various PVE backup code refactoring/improvements

Mostly preparation for our external backup plugin work, but fine to
already commit now.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

debian/changelog

@@ -1,3 +1,27 @@
+pve-qemu-kvm (9.0.2-4) bookworm; urgency=medium
+
+  * async snapshot: ensure any dynamic vCPU-throttling applied for
+    auto-converge gets always disabled again after finishing the snapshot.
+
+ -- Proxmox Support Team <support@proxmox.com>  Sun, 10 Nov 2024 11:23:09 +0100
+
+pve-qemu-kvm (9.0.2-3) bookworm; urgency=medium
+
+  * pick up fix for VirtIO PCI regressions
+
+  * pick up stable fixes for 9.0, including fixes for VirtIO-net, ARM and
+    x86(_64) emulation, CVEs to harden NBD server against malicious clients,
+    as well as a few others (VNC, physmem, Intel IOMMU, ...).
+
+ -- Proxmox Support Team <support@proxmox.com>  Fri, 06 Sep 2024 16:21:42 +0200
+
+pve-qemu-kvm (9.0.2-2) bookworm; urgency=medium
+
+  * actually update submodule to QEMU 9.0.2. The previous release was still
+    based on 9.0.0 by mistake.
+
+ -- Proxmox Support Team <support@proxmox.com>  Wed, 07 Aug 2024 10:16:01 +0200
+
 pve-qemu-kvm (9.0.2-1) bookworm; urgency=medium
 
   * update submodule and patches to QEMU 9.0.2. While our version had most

debian/patches/extra/0006-Revert-virtio-pci-fix-use-of-a-released-vector.patch

@@ -1,87 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Fiona Ebner <f.ebner@proxmox.com>
-Date: Thu, 16 May 2024 12:59:52 +0200
-Subject: [PATCH] Revert "virtio-pci: fix use of a released vector"
-
-This reverts commit 2ce6cff94df2650c460f809e5ad263f1d22507c0.
-
-The fix causes some issues:
-https://gitlab.com/qemu-project/qemu/-/issues/2321
-https://gitlab.com/qemu-project/qemu/-/issues/2334
-
-The CVE fixed by commit 2ce6cff94d ("virtio-pci: fix use of a released
-vector") is CVE-2024-4693 [0] and allows a malicious guest that
-controls the boot process in the guest to crash its QEMU process.
-
-The issues sound worse than the CVE, so revert until there is a proper
-fix.
-
-[0]: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4693
-
-Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
----
- hw/virtio/virtio-pci.c | 37 ++-----------------------------------
- 1 file changed, 2 insertions(+), 35 deletions(-)
-
-diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
-index e04218a9fb..fd66713848 100644
---- a/hw/virtio/virtio-pci.c
-+++ b/hw/virtio/virtio-pci.c
-@@ -1410,38 +1410,6 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
-     return offset;
- }
- 
--static void virtio_pci_set_vector(VirtIODevice *vdev,
--                                  VirtIOPCIProxy *proxy,
--                                  int queue_no, uint16_t old_vector,
--                                  uint16_t new_vector)
--{
--    bool kvm_irqfd = (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
--        msix_enabled(&proxy->pci_dev) && kvm_msi_via_irqfd_enabled();
--
--    if (new_vector == old_vector) {
--        return;
--    }
--
--    /*
--     * If the device uses irqfd and the vector changes after DRIVER_OK is
--     * set, we need to release the old vector and set up the new one.
--     * Otherwise just need to set the new vector on the device.
--     */
--    if (kvm_irqfd && old_vector != VIRTIO_NO_VECTOR) {
--        kvm_virtio_pci_vector_release_one(proxy, queue_no);
--    }
--    /* Set the new vector on the device. */
--    if (queue_no == VIRTIO_CONFIG_IRQ_IDX) {
--        vdev->config_vector = new_vector;
--    } else {
--        virtio_queue_set_vector(vdev, queue_no, new_vector);
--    }
--    /* If the new vector changed need to set it up. */
--    if (kvm_irqfd && new_vector != VIRTIO_NO_VECTOR) {
--        kvm_virtio_pci_vector_use_one(proxy, queue_no);
--    }
--}
--
- int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
-                            uint8_t bar, uint64_t offset, uint64_t length,
-                            uint8_t id)
-@@ -1588,8 +1556,7 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
-         } else {
-             val = VIRTIO_NO_VECTOR;
-         }
--        virtio_pci_set_vector(vdev, proxy, VIRTIO_CONFIG_IRQ_IDX,
--                              vdev->config_vector, val);
-+        vdev->config_vector = val;
-         break;
-     case VIRTIO_PCI_COMMON_STATUS:
-         if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
-@@ -1629,7 +1596,7 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
-         } else {
-             val = VIRTIO_NO_VECTOR;
-         }
--        virtio_pci_set_vector(vdev, proxy, vdev->queue_sel, vector, val);
-+        virtio_queue_set_vector(vdev, vdev->queue_sel, val);
-         break;
-     case VIRTIO_PCI_COMMON_Q_ENABLE:
-         if (val == 1) {

debian/patches/extra/0017-virtio-pci-Fix-the-use-of-an-uninitialized-irqfd.patch

@@ -0,0 +1,77 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Cindy Lu <lulu@redhat.com>
+Date: Tue, 6 Aug 2024 17:37:12 +0800
+Subject: [PATCH] virtio-pci: Fix the use of an uninitialized irqfd
+
+The crash was reported in MAC OS and NixOS, here is the link for this bug
+https://gitlab.com/qemu-project/qemu/-/issues/2334
+https://gitlab.com/qemu-project/qemu/-/issues/2321
+
+In this bug, they are using the virtio_input device. The guest notifier was
+not supported for this device, The function virtio_pci_set_guest_notifiers()
+was not called, and the vector_irqfd was not initialized.
+
+So the fix is adding the check for vector_irqfd in virtio_pci_get_notifier()
+
+The function virtio_pci_get_notifier() can be used in various devices.
+It could also be called when VIRTIO_CONFIG_S_DRIVER_OK is not set. In this situation,
+the vector_irqfd being NULL is acceptable. We can allow the device continue to boot
+
+If the vector_irqfd still hasn't been initialized after VIRTIO_CONFIG_S_DRIVER_OK
+is set, it means that the function set_guest_notifiers was not called before the
+driver started. This indicates that the device is not using the notifier.
+At this point, we will let the check fail.
+
+This fix is verified in vyatta,MacOS,NixOS,fedora system.
+
+The bt tree for this bug is:
+Thread 6 "CPU 0/KVM" received signal SIGSEGV, Segmentation fault.
+[Switching to Thread 0x7c817be006c0 (LWP 1269146)]
+kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817
+817         if (irqfd->users == 0) {
+(gdb) thread apply all bt
+...
+Thread 6 (Thread 0x7c817be006c0 (LWP 1269146) "CPU 0/KVM"):
+0  kvm_virtio_pci_vq_vector_use () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:817
+1  kvm_virtio_pci_vector_use_one () at ../qemu-9.0.0/hw/virtio/virtio-pci.c:893
+2  0x00005983657045e2 in memory_region_write_accessor () at ../qemu-9.0.0/system/memory.c:497
+3  0x0000598365704ba6 in access_with_adjusted_size () at ../qemu-9.0.0/system/memory.c:573
+4  0x0000598365705059 in memory_region_dispatch_write () at ../qemu-9.0.0/system/memory.c:1528
+5  0x00005983659b8e1f in flatview_write_continue_step.isra.0 () at ../qemu-9.0.0/system/physmem.c:2713
+6  0x000059836570ba7d in flatview_write_continue () at ../qemu-9.0.0/system/physmem.c:2743
+7  flatview_write () at ../qemu-9.0.0/system/physmem.c:2774
+8  0x000059836570bb76 in address_space_write () at ../qemu-9.0.0/system/physmem.c:2894
+9  0x0000598365763afe in address_space_rw () at ../qemu-9.0.0/system/physmem.c:2904
+10 kvm_cpu_exec () at ../qemu-9.0.0/accel/kvm/kvm-all.c:2917
+11 0x000059836576656e in kvm_vcpu_thread_fn () at ../qemu-9.0.0/accel/kvm/kvm-accel-ops.c:50
+12 0x0000598365926ca8 in qemu_thread_start () at ../qemu-9.0.0/util/qemu-thread-posix.c:541
+13 0x00007c8185bcd1cf in ??? () at /usr/lib/libc.so.6
+14 0x00007c8185c4e504 in clone () at /usr/lib/libc.so.6
+
+Fixes: 2ce6cff94d ("virtio-pci: fix use of a released vector")
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Cindy Lu <lulu@redhat.com>
+Message-Id: <20240806093715.65105-1-lulu@redhat.com>
+Acked-by: Jason Wang <jasowang@redhat.com>
+Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
+Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+(cherry picked from commit a8e63ff289d137197ad7a701a587cc432872d798)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ hw/virtio/virtio-pci.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
+index e04218a9fb..389bab003f 100644
+--- a/hw/virtio/virtio-pci.c
++++ b/hw/virtio/virtio-pci.c
+@@ -860,6 +860,9 @@ static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
+     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+     VirtQueue *vq;
+ 
++    if (!proxy->vector_irqfd && vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)
++        return -1;
++
+     if (queue_no == VIRTIO_CONFIG_IRQ_IDX) {
+         *n = virtio_config_get_guest_notifier(vdev);
+         *vector = vdev->config_vector;

debian/patches/extra/0018-virtio-net-Ensure-queue-index-fits-with-RSS.patch

@@ -0,0 +1,35 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Akihiko Odaki <akihiko.odaki@daynix.com>
+Date: Mon, 1 Jul 2024 20:58:04 +0900
+Subject: [PATCH] virtio-net: Ensure queue index fits with RSS
+
+Ensure the queue index points to a valid queue when software RSS
+enabled. The new calculation matches with the behavior of Linux's TAP
+device with the RSS eBPF program.
+
+Fixes: 4474e37a5b3a ("virtio-net: implement RX RSS processing")
+Reported-by: Zhibin Hu <huzhibin5@huawei.com>
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
+Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+(cherry picked from commit f1595ceb9aad36a6c1da95bcb77ab9509b38822d)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ hw/net/virtio-net.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
+index 3644bfd91b..f48588638d 100644
+--- a/hw/net/virtio-net.c
++++ b/hw/net/virtio-net.c
+@@ -1949,7 +1949,8 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
+     if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
+         int index = virtio_net_process_rss(nc, buf, size);
+         if (index >= 0) {
+-            NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
++            NetClientState *nc2 =
++                qemu_get_subqueue(n->nic, index % n->curr_queue_pairs);
+             return virtio_net_receive_rcu(nc2, buf, size, true);
+         }
+     }

debian/patches/extra/0019-virtio-net-Fix-network-stall-at-the-host-side-waitin.patch

@@ -0,0 +1,338 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: thomas <east.moutain.yang@gmail.com>
+Date: Fri, 12 Jul 2024 11:10:53 +0800
+Subject: [PATCH] virtio-net: Fix network stall at the host side waiting for
+ kick
+
+Patch 06b12970174 ("virtio-net: fix network stall under load")
+added double-check to test whether the available buffer size
+can satisfy the request or not, in case the guest has added
+some buffers to the avail ring simultaneously after the first
+check. It will be lucky if the available buffer size becomes
+okay after the double-check, then the host can send the packet
+to the guest. If the buffer size still can't satisfy the request,
+even if the guest has added some buffers, viritio-net would
+stall at the host side forever.
+
+The patch enables notification and checks whether the guest has
+added some buffers since last check of available buffers when
+the available buffers are insufficient. If no buffer is added,
+return false, else recheck the available buffers in the loop.
+If the available buffers are sufficient, disable notification
+and return true.
+
+Changes:
+1. Change the return type of virtqueue_get_avail_bytes() from void
+   to int, it returns an opaque that represents the shadow_avail_idx
+   of the virtqueue on success, else -1 on error.
+2. Add a new API: virtio_queue_enable_notification_and_check(),
+   it takes an opaque as input arg which is returned from
+   virtqueue_get_avail_bytes(). It enables notification firstly,
+   then checks whether the guest has added some buffers since
+   last check of available buffers or not by virtio_queue_poll(),
+   return ture if yes.
+
+The patch also reverts patch "06b12970174".
+
+The case below can reproduce the stall.
+
+                                       Guest 0
+                                     +--------+
+                                     | iperf  |
+                    ---------------> | server |
+         Host       |                +--------+
+       +--------+   |                    ...
+       | iperf  |----
+       | client |----                  Guest n
+       +--------+   |                +--------+
+                    |                | iperf  |
+                    ---------------> | server |
+                                     +--------+
+
+Boot many guests from qemu with virtio network:
+ qemu ... -netdev tap,id=net_x \
+    -device virtio-net-pci-non-transitional,\
+    iommu_platform=on,mac=xx:xx:xx:xx:xx:xx,netdev=net_x
+
+Each guest acts as iperf server with commands below:
+ iperf3 -s -D -i 10 -p 8001
+ iperf3 -s -D -i 10 -p 8002
+
+The host as iperf client:
+ iperf3 -c guest_IP -p 8001 -i 30 -w 256k -P 20 -t 40000
+ iperf3 -c guest_IP -p 8002 -i 30 -w 256k -P 20 -t 40000
+
+After some time, the host loses connection to the guest,
+the guest can send packet to the host, but can't receive
+packet from the host.
+
+It's more likely to happen if SWIOTLB is enabled in the guest,
+allocating and freeing bounce buffer takes some CPU ticks,
+copying from/to bounce buffer takes more CPU ticks, compared
+with that there is no bounce buffer in the guest.
+Once the rate of producing packets from the host approximates
+the rate of receiveing packets in the guest, the guest would
+loop in NAPI.
+
+         receive packets    ---
+               |             |
+               v             |
+           free buf      virtnet_poll
+               |             |
+               v             |
+     add buf to avail ring  ---
+               |
+               |  need kick the host?
+               |  NAPI continues
+               v
+         receive packets    ---
+               |             |
+               v             |
+           free buf      virtnet_poll
+               |             |
+               v             |
+     add buf to avail ring  ---
+               |
+               v
+              ...           ...
+
+On the other hand, the host fetches free buf from avail
+ring, if the buf in the avail ring is not enough, the
+host notifies the guest the event by writing the avail
+idx read from avail ring to the event idx of used ring,
+then the host goes to sleep, waiting for the kick signal
+from the guest.
+
+Once the guest finds the host is waiting for kick singal
+(in virtqueue_kick_prepare_split()), it kicks the host.
+
+The host may stall forever at the sequences below:
+
+         Host                        Guest
+     ------------                 -----------
+ fetch buf, send packet           receive packet ---
+         ...                          ...         |
+ fetch buf, send packet             add buf       |
+         ...                        add buf   virtnet_poll
+    buf not enough      avail idx-> add buf       |
+    read avail idx                  add buf       |
+                                    add buf      ---
+                                  receive packet ---
+    write event idx                   ...         |
+    wait for kick                   add buf   virtnet_poll
+                                      ...         |
+                                                 ---
+                                 no more packet, exit NAPI
+
+In the first loop of NAPI above, indicated in the range of
+virtnet_poll above, the host is sending packets while the
+guest is receiving packets and adding buffers.
+ step 1: The buf is not enough, for example, a big packet
+         needs 5 buf, but the available buf count is 3.
+         The host read current avail idx.
+ step 2: The guest adds some buf, then checks whether the
+         host is waiting for kick signal, not at this time.
+         The used ring is not empty, the guest continues
+         the second loop of NAPI.
+ step 3: The host writes the avail idx read from avail
+         ring to used ring as event idx via
+         virtio_queue_set_notification(q->rx_vq, 1).
+ step 4: At the end of the second loop of NAPI, recheck
+         whether kick is needed, as the event idx in the
+         used ring written by the host is beyound the
+         range of kick condition, the guest will not
+         send kick signal to the host.
+
+Fixes: 06b12970174 ("virtio-net: fix network stall under load")
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Wencheng Yang <east.moutain.yang@gmail.com>
+Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+(cherry picked from commit f937309fbdbb48c354220a3e7110c202ae4aa7fa)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ hw/net/virtio-net.c        | 28 ++++++++++-------
+ hw/virtio/virtio.c         | 64 +++++++++++++++++++++++++++++++++++---
+ include/hw/virtio/virtio.h | 21 +++++++++++--
+ 3 files changed, 94 insertions(+), 19 deletions(-)
+
+diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
+index f48588638d..d4b979d343 100644
+--- a/hw/net/virtio-net.c
++++ b/hw/net/virtio-net.c
+@@ -1680,24 +1680,28 @@ static bool virtio_net_can_receive(NetClientState *nc)
+ 
+ static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
+ {
++    int opaque;
++    unsigned int in_bytes;
+     VirtIONet *n = q->n;
+-    if (virtio_queue_empty(q->rx_vq) ||
+-        (n->mergeable_rx_bufs &&
+-         !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
+-        virtio_queue_set_notification(q->rx_vq, 1);
+-
+-        /* To avoid a race condition where the guest has made some buffers
+-         * available after the above check but before notification was
+-         * enabled, check for available buffers again.
+-         */
+-        if (virtio_queue_empty(q->rx_vq) ||
+-            (n->mergeable_rx_bufs &&
+-             !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
++
++    while (virtio_queue_empty(q->rx_vq) || n->mergeable_rx_bufs) {
++        opaque = virtqueue_get_avail_bytes(q->rx_vq, &in_bytes, NULL,
++                                           bufsize, 0);
++        /* Buffer is enough, disable notifiaction */
++        if (bufsize <= in_bytes) {
++            break;
++        }
++
++        if (virtio_queue_enable_notification_and_check(q->rx_vq, opaque)) {
++            /* Guest has added some buffers, try again */
++            continue;
++        } else {
+             return 0;
+         }
+     }
+ 
+     virtio_queue_set_notification(q->rx_vq, 0);
++
+     return 1;
+ }
+ 
+diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
+index fd2dfe3a6b..08fba6b2d8 100644
+--- a/hw/virtio/virtio.c
++++ b/hw/virtio/virtio.c
+@@ -743,6 +743,60 @@ int virtio_queue_empty(VirtQueue *vq)
+     }
+ }
+ 
++static bool virtio_queue_split_poll(VirtQueue *vq, unsigned shadow_idx)
++{
++    if (unlikely(!vq->vring.avail)) {
++        return false;
++    }
++
++    return (uint16_t)shadow_idx != vring_avail_idx(vq);
++}
++
++static bool virtio_queue_packed_poll(VirtQueue *vq, unsigned shadow_idx)
++{
++    VRingPackedDesc desc;
++    VRingMemoryRegionCaches *caches;
++
++    if (unlikely(!vq->vring.desc)) {
++        return false;
++    }
++
++    caches = vring_get_region_caches(vq);
++    if (!caches) {
++        return false;
++    }
++
++    vring_packed_desc_read(vq->vdev, &desc, &caches->desc,
++                           shadow_idx, true);
++
++    return is_desc_avail(desc.flags, vq->shadow_avail_wrap_counter);
++}
++
++static bool virtio_queue_poll(VirtQueue *vq, unsigned shadow_idx)
++{
++    if (virtio_device_disabled(vq->vdev)) {
++        return false;
++    }
++
++    if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) {
++        return virtio_queue_packed_poll(vq, shadow_idx);
++    } else {
++        return virtio_queue_split_poll(vq, shadow_idx);
++    }
++}
++
++bool virtio_queue_enable_notification_and_check(VirtQueue *vq,
++                                                int opaque)
++{
++    virtio_queue_set_notification(vq, 1);
++
++    if (opaque >= 0) {
++        return virtio_queue_poll(vq, (unsigned)opaque);
++    } else {
++        return false;
++    }
++}
++
+ static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,
+                                unsigned int len)
+ {
+@@ -1330,9 +1384,9 @@ err:
+     goto done;
+ }
+ 
+-void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+-                               unsigned int *out_bytes,
+-                               unsigned max_in_bytes, unsigned max_out_bytes)
++int virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
++                              unsigned int *out_bytes, unsigned max_in_bytes,
++                              unsigned max_out_bytes)
+ {
+     uint16_t desc_size;
+     VRingMemoryRegionCaches *caches;
+@@ -1365,7 +1419,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+                                         caches);
+     }
+ 
+-    return;
++    return (int)vq->shadow_avail_idx;
+ err:
+     if (in_bytes) {
+         *in_bytes = 0;
+@@ -1373,6 +1427,8 @@ err:
+     if (out_bytes) {
+         *out_bytes = 0;
+     }
++
++    return -1;
+ }
+ 
+ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
+index 2eafad17b8..8b4da92889 100644
+--- a/include/hw/virtio/virtio.h
++++ b/include/hw/virtio/virtio.h
+@@ -271,9 +271,13 @@ void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
+                                 VirtQueueElement *elem);
+ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+                           unsigned int out_bytes);
+-void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+-                               unsigned int *out_bytes,
+-                               unsigned max_in_bytes, unsigned max_out_bytes);
++/**
++ * Return <0 on error or an opaque >=0 to pass to
++ * virtio_queue_enable_notification_and_check on success.
++ */
++int virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
++                              unsigned int *out_bytes, unsigned max_in_bytes,
++                              unsigned max_out_bytes);
+ 
+ void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
+ void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
+@@ -307,6 +311,17 @@ int virtio_queue_ready(VirtQueue *vq);
+ 
+ int virtio_queue_empty(VirtQueue *vq);
+ 
++/**
++ * Enable notification and check whether guest has added some
++ * buffers since last call to virtqueue_get_avail_bytes.
++ *
++ * @opaque: value returned from virtqueue_get_avail_bytes
++ */
++bool virtio_queue_enable_notification_and_check(VirtQueue *vq,
++                                                int opaque);
++
++void virtio_queue_set_shadow_avail_idx(VirtQueue *vq, uint16_t idx);
++
+ /* Host binding interface.  */
+ 
+ uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);

debian/patches/extra/0020-net-Reinstate-net-nic-model-help-output-as-documente.patch

@@ -0,0 +1,70 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: David Woodhouse <dwmw@amazon.co.uk>
+Date: Tue, 9 Jul 2024 13:34:44 +0100
+Subject: [PATCH] net: Reinstate '-net nic, model=help' output as documented in
+ man page
+
+While refactoring the NIC initialization code, I broke '-net nic,model=help'
+which no longer outputs a list of available NIC models.
+
+Fixes: 2cdeca04adab ("net: report list of available models according to platform")
+Cc: qemu-stable@nongnu.org
+Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
+Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+(cherry picked from commit 64f75f57f9d2c8c12ac6d9355fa5d3a2af5879ca)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ net/net.c | 25 ++++++++++++++++++++++---
+ 1 file changed, 22 insertions(+), 3 deletions(-)
+
+diff --git a/net/net.c b/net/net.c
+index a2f0c828bb..e6ca2529bb 100644
+--- a/net/net.c
++++ b/net/net.c
+@@ -1150,6 +1150,21 @@ NICInfo *qemu_find_nic_info(const char *typename, bool match_default,
+     return NULL;
+ }
+ 
++static bool is_nic_model_help_option(const char *model)
++{
++    if (model && is_help_option(model)) {
++        /*
++         * Trigger the help output by instantiating the hash table which
++         * will gather tha available models as they get registered.
++         */
++        if (!nic_model_help) {
++            nic_model_help = g_hash_table_new_full(g_str_hash, g_str_equal,
++                                                   g_free, NULL);
++        }
++        return true;
++    }
++    return false;
++}
+ 
+ /* "I have created a device. Please configure it if you can" */
+ bool qemu_configure_nic_device(DeviceState *dev, bool match_default,
+@@ -1733,6 +1748,12 @@ void net_check_clients(void)
+ 
+ static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
+ {
++    const char *model = qemu_opt_get_del(opts, "model");
++
++    if (is_nic_model_help_option(model)) {
++        return 0;
++    }
++
+     return net_client_init(opts, false, errp);
+ }
+ 
+@@ -1789,9 +1810,7 @@ static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
+     memset(ni, 0, sizeof(*ni));
+     ni->model = qemu_opt_get_del(opts, "model");
+ 
+-    if (!nic_model_help && !g_strcmp0(ni->model, "help")) {
+-        nic_model_help = g_hash_table_new_full(g_str_hash, g_str_equal,
+-                                               g_free, NULL);
++    if (is_nic_model_help_option(ni->model)) {
+         return 0;
+     }
+ 

debian/patches/extra/0021-net-Fix-net-nic-model-for-non-help-arguments.patch

@@ -0,0 +1,32 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: David Woodhouse <dwmw@amazon.co.uk>
+Date: Tue, 6 Aug 2024 18:21:37 +0100
+Subject: [PATCH] net: Fix '-net nic,model=' for non-help arguments
+
+Oops, don't *delete* the model option when checking for 'help'.
+
+Fixes: 64f75f57f9d2 ("net: Reinstate '-net nic, model=help' output as documented in man page")
+Reported-by: Hans <sungdgdhtryrt@gmail.com>
+Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
+Cc: qemu-stable@nongnu.org
+Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+(cherry picked from commit fa62cb989a9146c82f8f172715042852f5d36200)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ net/net.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/net/net.c b/net/net.c
+index e6ca2529bb..897bb936cf 100644
+--- a/net/net.c
++++ b/net/net.c
+@@ -1748,7 +1748,7 @@ void net_check_clients(void)
+ 
+ static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
+ {
+-    const char *model = qemu_opt_get_del(opts, "model");
++    const char *model = qemu_opt_get(opts, "model");
+ 
+     if (is_nic_model_help_option(model)) {
+         return 0;

debian/patches/extra/0022-target-arm-Don-t-assert-for-128-bit-tile-accesses-wh.patch

@@ -0,0 +1,57 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Peter Maydell <peter.maydell@linaro.org>
+Date: Mon, 22 Jul 2024 18:29:54 +0100
+Subject: [PATCH] target/arm: Don't assert for 128-bit tile accesses when SVL
+ is 128
+
+For an instruction which accesses a 128-bit element tile when
+the SVL is also 128 (for example MOV z0.Q, p0/M, ZA0H.Q[w0,0]),
+we will assert in get_tile_rowcol():
+
+qemu-system-aarch64: ../../tcg/tcg-op.c:926: tcg_gen_deposit_z_i32: Assertion `len > 0' failed.
+
+This happens because we calculate
+    len = ctz32(streaming_vec_reg_size(s)) - esz;$
+but if the SVL and the element size are the same len is 0, and
+the deposit operation asserts.
+
+In this case the ZA storage contains exactly one 128 bit
+element ZA tile, and the horizontal or vertical slice is just
+that tile. This means that regardless of the index value in
+the Ws register, we always access that tile. (In pseudocode terms,
+we calculate (index + offset) MOD 1, which is 0.)
+
+Special case the len == 0 case to avoid hitting the assertion
+in tcg_gen_deposit_z_i32().
+
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
+Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
+Message-id: 20240722172957.1041231-2-peter.maydell@linaro.org
+(cherry picked from commit 56f1c0db928aae0b83fd91c89ddb226b137e2b21)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/arm/tcg/translate-sme.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/target/arm/tcg/translate-sme.c b/target/arm/tcg/translate-sme.c
+index 185a8a917b..a50a419af2 100644
+--- a/target/arm/tcg/translate-sme.c
++++ b/target/arm/tcg/translate-sme.c
+@@ -49,7 +49,15 @@ static TCGv_ptr get_tile_rowcol(DisasContext *s, int esz, int rs,
+     /* Prepare a power-of-two modulo via extraction of @len bits. */
+     len = ctz32(streaming_vec_reg_size(s)) - esz;
+ 
+-    if (vertical) {
++    if (!len) {
++        /*
++         * SVL is 128 and the element size is 128. There is exactly
++         * one 128x128 tile in the ZA storage, and so we calculate
++         * (Rs + imm) MOD 1, which is always 0. We need to special case
++         * this because TCG doesn't allow deposit ops with len 0.
++         */
++        tcg_gen_movi_i32(tmp, 0);
++    } else if (vertical) {
+         /*
+          * Compute the byte offset of the index within the tile:
+          *     (index % (svl / size)) * size

debian/patches/extra/0023-target-arm-Fix-UMOPA-UMOPS-of-16-bit-values.patch

@@ -0,0 +1,59 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Peter Maydell <peter.maydell@linaro.org>
+Date: Mon, 22 Jul 2024 18:29:55 +0100
+Subject: [PATCH] target/arm: Fix UMOPA/UMOPS of 16-bit values
+
+The UMOPA/UMOPS instructions are supposed to multiply unsigned 8 or
+16 bit elements and accumulate the products into a 64-bit element.
+In the Arm ARM pseudocode, this is done with the usual
+infinite-precision signed arithmetic.  However our implementation
+doesn't quite get it right, because in the DEF_IMOP_64() macro we do:
+  sum += (NTYPE)(n >> 0) * (MTYPE)(m >> 0);
+
+where NTYPE and MTYPE are uint16_t or int16_t.  In the uint16_t case,
+the C usual arithmetic conversions mean the values are converted to
+"int" type and the multiply is done as a 32-bit multiply.  This means
+that if the inputs are, for example, 0xffff and 0xffff then the
+result is 0xFFFE0001 as an int, which is then promoted to uint64_t
+for the accumulation into sum; this promotion incorrectly sign
+extends the multiply.
+
+Avoid the incorrect sign extension by casting to int64_t before
+the multiply, so we do the multiply as 64-bit signed arithmetic,
+which is a type large enough that the multiply can never
+overflow into the sign bit.
+
+(The equivalent 8-bit operations in DEF_IMOP_32() are fine, because
+the 8-bit multiplies can never overflow into the sign bit of a
+32-bit integer.)
+
+Cc: qemu-stable@nongnu.org
+Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2372
+Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
+Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
+Message-id: 20240722172957.1041231-3-peter.maydell@linaro.org
+(cherry picked from commit ea3f5a90f036734522e9af3bffd77e69e9f47355)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/arm/tcg/sme_helper.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/target/arm/tcg/sme_helper.c b/target/arm/tcg/sme_helper.c
+index 5a6dd76489..f9001f5213 100644
+--- a/target/arm/tcg/sme_helper.c
++++ b/target/arm/tcg/sme_helper.c
+@@ -1146,10 +1146,10 @@ static uint64_t NAME(uint64_t n, uint64_t m, uint64_t a, uint8_t p, bool neg) \
+     uint64_t sum = 0;                                                       \
+     /* Apply P to N as a mask, making the inactive elements 0. */           \
+     n &= expand_pred_h(p);                                                  \
+-    sum += (NTYPE)(n >> 0) * (MTYPE)(m >> 0);                               \
+-    sum += (NTYPE)(n >> 16) * (MTYPE)(m >> 16);                             \
+-    sum += (NTYPE)(n >> 32) * (MTYPE)(m >> 32);                             \
+-    sum += (NTYPE)(n >> 48) * (MTYPE)(m >> 48);                             \
++    sum += (int64_t)(NTYPE)(n >> 0) * (MTYPE)(m >> 0);                      \
++    sum += (int64_t)(NTYPE)(n >> 16) * (MTYPE)(m >> 16);                    \
++    sum += (int64_t)(NTYPE)(n >> 32) * (MTYPE)(m >> 32);                    \
++    sum += (int64_t)(NTYPE)(n >> 48) * (MTYPE)(m >> 48);                    \
+     return neg ? a - sum : a + sum;                                         \
+ }
+ 

debian/patches/extra/0024-target-arm-Avoid-shifts-by-1-in-tszimm_shr-and-tszim.patch

@@ -0,0 +1,62 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Peter Maydell <peter.maydell@linaro.org>
+Date: Mon, 22 Jul 2024 18:29:56 +0100
+Subject: [PATCH] target/arm: Avoid shifts by -1 in tszimm_shr() and
+ tszimm_shl()
+
+The function tszimm_esz() returns a shift amount, or possibly -1 in
+certain cases that correspond to unallocated encodings in the
+instruction set.  We catch these later in the trans_ functions
+(generally with an "a-esz < 0" check), but before we do the
+decodetree-generated code will also call tszimm_shr() or tszimm_sl(),
+which will use the tszimm_esz() return value as a shift count without
+checking that it is not negative, which is undefined behaviour.
+
+Avoid the UB by checking the return value in tszimm_shr() and
+tszimm_shl().
+
+Cc: qemu-stable@nongnu.org
+Resolves: Coverity CID 1547617, 1547694
+Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
+Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
+Message-id: 20240722172957.1041231-4-peter.maydell@linaro.org
+(cherry picked from commit 76916dfa89e8900639c1055c07a295c06628a0bc)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/arm/tcg/translate-sve.c | 18 ++++++++++++++++--
+ 1 file changed, 16 insertions(+), 2 deletions(-)
+
+diff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c
+index ada05aa530..466a19c25a 100644
+--- a/target/arm/tcg/translate-sve.c
++++ b/target/arm/tcg/translate-sve.c
+@@ -50,13 +50,27 @@ static int tszimm_esz(DisasContext *s, int x)
+ 
+ static int tszimm_shr(DisasContext *s, int x)
+ {
+-    return (16 << tszimm_esz(s, x)) - x;
++    /*
++     * We won't use the tszimm_shr() value if tszimm_esz() returns -1 (the
++     * trans function will check for esz < 0), so we can return any
++     * value we like from here in that case as long as we avoid UB.
++     */
++    int esz = tszimm_esz(s, x);
++    if (esz < 0) {
++        return esz;
++    }
++    return (16 << esz) - x;
+ }
+ 
+ /* See e.g. LSL (immediate, predicated).  */
+ static int tszimm_shl(DisasContext *s, int x)
+ {
+-    return x - (8 << tszimm_esz(s, x));
++    /* As with tszimm_shr(), value will be unused if esz < 0 */
++    int esz = tszimm_esz(s, x);
++    if (esz < 0) {
++        return esz;
++    }
++    return x - (8 << esz);
+ }
+ 
+ /* The SH bit is in bit 8.  Extract the low 8 and shift.  */

debian/patches/extra/0025-target-arm-Ignore-SMCR_EL2.LEN-and-SVCR_EL2.LEN-if-E.patch

@@ -0,0 +1,41 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Peter Maydell <peter.maydell@linaro.org>
+Date: Mon, 22 Jul 2024 18:29:57 +0100
+Subject: [PATCH] target/arm: Ignore SMCR_EL2.LEN and SVCR_EL2.LEN if EL2 is
+ not enabled
+
+When determining the current vector length, the SMCR_EL2.LEN and
+SVCR_EL2.LEN settings should only be considered if EL2 is enabled
+(compare the pseudocode CurrentSVL and CurrentNSVL which call
+EL2Enabled()).
+
+We were checking against ARM_FEATURE_EL2 rather than calling
+arm_is_el2_enabled(), which meant that we would look at
+SMCR_EL2/SVCR_EL2 when in Secure EL1 or Secure EL0 even if Secure EL2
+was not enabled.
+
+Use the correct check in sve_vqm1_for_el_sm().
+
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
+Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
+Message-id: 20240722172957.1041231-5-peter.maydell@linaro.org
+(cherry picked from commit f573ac059ed060234fcef4299fae9e500d357c33)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/arm/helper.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/target/arm/helper.c b/target/arm/helper.c
+index a620481d7c..42044ae14b 100644
+--- a/target/arm/helper.c
++++ b/target/arm/helper.c
+@@ -7191,7 +7191,7 @@ uint32_t sve_vqm1_for_el_sm(CPUARMState *env, int el, bool sm)
+     if (el <= 1 && !el_is_in_host(env, el)) {
+         len = MIN(len, 0xf & (uint32_t)cr[1]);
+     }
+-    if (el <= 2 && arm_feature(env, ARM_FEATURE_EL2)) {
++    if (el <= 2 && arm_is_el2_enabled(env)) {
+         len = MIN(len, 0xf & (uint32_t)cr[2]);
+     }
+     if (arm_feature(env, ARM_FEATURE_EL3)) {

debian/patches/extra/0026-target-arm-Handle-denormals-correctly-for-FMOPA-wide.patch

@@ -0,0 +1,164 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Peter Maydell <peter.maydell@linaro.org>
+Date: Thu, 1 Aug 2024 10:15:03 +0100
+Subject: [PATCH] target/arm: Handle denormals correctly for FMOPA (widening)
+
+The FMOPA (widening) SME instruction takes pairs of half-precision
+floating point values, widens them to single-precision, does a
+two-way dot product and accumulates the results into a
+single-precision destination.  We don't quite correctly handle the
+FPCR bits FZ and FZ16 which control flushing of denormal inputs and
+outputs.  This is because at the moment we pass a single float_status
+value to the helper function, which then uses that configuration for
+all the fp operations it does.  However, because the inputs to this
+operation are float16 and the outputs are float32 we need to use the
+fp_status_f16 for the float16 input widening but the normal fp_status
+for everything else.  Otherwise we will apply the flushing control
+FPCR.FZ16 to the 32-bit output rather than the FPCR.FZ control, and
+incorrectly flush a denormal output to zero when we should not (or
+vice-versa).
+
+(In commit 207d30b5fdb5b we tried to fix the FZ handling but
+didn't get it right, switching from "use FPCR.FZ for everything" to
+"use FPCR.FZ16 for everything".)
+
+Pass the CPU env to the sme_fmopa_h helper instead of an fp_status
+pointer, and have the helper pass an extra fp_status into the
+f16_dotadd() function so that we can use the right status for the
+right parts of this operation.
+
+Cc: qemu-stable@nongnu.org
+Fixes: 207d30b5fdb5 ("target/arm: Use FPST_F16 for SME FMOPA (widening)")
+Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2373
+Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
+Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
+(cherry picked from commit 55f9f4ee018c5ccea81d8c8c586756d7711ae46f)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/arm/tcg/helper-sme.h    |  2 +-
+ target/arm/tcg/sme_helper.c    | 39 +++++++++++++++++++++++-----------
+ target/arm/tcg/translate-sme.c | 25 ++++++++++++++++++++--
+ 3 files changed, 51 insertions(+), 15 deletions(-)
+
+diff --git a/target/arm/tcg/helper-sme.h b/target/arm/tcg/helper-sme.h
+index 27eef49a11..d22bf9d21b 100644
+--- a/target/arm/tcg/helper-sme.h
++++ b/target/arm/tcg/helper-sme.h
+@@ -121,7 +121,7 @@ DEF_HELPER_FLAGS_5(sme_addha_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+ DEF_HELPER_FLAGS_5(sme_addva_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+ 
+ DEF_HELPER_FLAGS_7(sme_fmopa_h, TCG_CALL_NO_RWG,
+-                   void, ptr, ptr, ptr, ptr, ptr, ptr, i32)
++                   void, ptr, ptr, ptr, ptr, ptr, env, i32)
+ DEF_HELPER_FLAGS_7(sme_fmopa_s, TCG_CALL_NO_RWG,
+                    void, ptr, ptr, ptr, ptr, ptr, ptr, i32)
+ DEF_HELPER_FLAGS_7(sme_fmopa_d, TCG_CALL_NO_RWG,
+diff --git a/target/arm/tcg/sme_helper.c b/target/arm/tcg/sme_helper.c
+index f9001f5213..3906bb51c0 100644
+--- a/target/arm/tcg/sme_helper.c
++++ b/target/arm/tcg/sme_helper.c
+@@ -976,12 +976,23 @@ static inline uint32_t f16mop_adj_pair(uint32_t pair, uint32_t pg, uint32_t neg)
+ }
+ 
+ static float32 f16_dotadd(float32 sum, uint32_t e1, uint32_t e2,
+-                          float_status *s_std, float_status *s_odd)
++                          float_status *s_f16, float_status *s_std,
++                          float_status *s_odd)
+ {
+-    float64 e1r = float16_to_float64(e1 & 0xffff, true, s_std);
+-    float64 e1c = float16_to_float64(e1 >> 16, true, s_std);
+-    float64 e2r = float16_to_float64(e2 & 0xffff, true, s_std);
+-    float64 e2c = float16_to_float64(e2 >> 16, true, s_std);
++    /*
++     * We need three different float_status for different parts of this
++     * operation:
++     *  - the input conversion of the float16 values must use the
++     *    f16-specific float_status, so that the FPCR.FZ16 control is applied
++     *  - operations on float32 including the final accumulation must use
++     *    the normal float_status, so that FPCR.FZ is applied
++     *  - we have pre-set-up copy of s_std which is set to round-to-odd,
++     *    for the multiply (see below)
++     */
++    float64 e1r = float16_to_float64(e1 & 0xffff, true, s_f16);
++    float64 e1c = float16_to_float64(e1 >> 16, true, s_f16);
++    float64 e2r = float16_to_float64(e2 & 0xffff, true, s_f16);
++    float64 e2c = float16_to_float64(e2 >> 16, true, s_f16);
+     float64 t64;
+     float32 t32;
+ 
+@@ -1003,20 +1014,23 @@ static float32 f16_dotadd(float32 sum, uint32_t e1, uint32_t e2,
+ }
+ 
+ void HELPER(sme_fmopa_h)(void *vza, void *vzn, void *vzm, void *vpn,
+-                         void *vpm, void *vst, uint32_t desc)
++                         void *vpm, CPUARMState *env, uint32_t desc)
+ {
+     intptr_t row, col, oprsz = simd_maxsz(desc);
+     uint32_t neg = simd_data(desc) * 0x80008000u;
+     uint16_t *pn = vpn, *pm = vpm;
+-    float_status fpst_odd, fpst_std;
++    float_status fpst_odd, fpst_std, fpst_f16;
+ 
+     /*
+-     * Make a copy of float_status because this operation does not
+-     * update the cumulative fp exception status.  It also produces
+-     * default nans.  Make a second copy with round-to-odd -- see above.
++     * Make copies of fp_status and fp_status_f16, because this operation
++     * does not update the cumulative fp exception status.  It also
++     * produces default NaNs. We also need a second copy of fp_status with
++     * round-to-odd -- see above.
+      */
+-    fpst_std = *(float_status *)vst;
++    fpst_f16 = env->vfp.fp_status_f16;
++    fpst_std = env->vfp.fp_status;
+     set_default_nan_mode(true, &fpst_std);
++    set_default_nan_mode(true, &fpst_f16);
+     fpst_odd = fpst_std;
+     set_float_rounding_mode(float_round_to_odd, &fpst_odd);
+ 
+@@ -1036,7 +1050,8 @@ void HELPER(sme_fmopa_h)(void *vza, void *vzn, void *vzm, void *vpn,
+                         uint32_t m = *(uint32_t *)(vzm + H1_4(col));
+ 
+                         m = f16mop_adj_pair(m, pcol, 0);
+-                        *a = f16_dotadd(*a, n, m, &fpst_std, &fpst_odd);
++                        *a = f16_dotadd(*a, n, m,
++                                        &fpst_f16, &fpst_std, &fpst_odd);
+                     }
+                     col += 4;
+                     pcol >>= 4;
+diff --git a/target/arm/tcg/translate-sme.c b/target/arm/tcg/translate-sme.c
+index a50a419af2..ae42ddef7b 100644
+--- a/target/arm/tcg/translate-sme.c
++++ b/target/arm/tcg/translate-sme.c
+@@ -334,8 +334,29 @@ static bool do_outprod_fpst(DisasContext *s, arg_op *a, MemOp esz,
+     return true;
+ }
+ 
+-TRANS_FEAT(FMOPA_h, aa64_sme, do_outprod_fpst, a,
+-           MO_32, FPST_FPCR_F16, gen_helper_sme_fmopa_h)
++static bool do_outprod_env(DisasContext *s, arg_op *a, MemOp esz,
++                           gen_helper_gvec_5_ptr *fn)
++{
++    int svl = streaming_vec_reg_size(s);
++    uint32_t desc = simd_desc(svl, svl, a->sub);
++    TCGv_ptr za, zn, zm, pn, pm;
++
++    if (!sme_smza_enabled_check(s)) {
++        return true;
++    }
++
++    za = get_tile(s, esz, a->zad);
++    zn = vec_full_reg_ptr(s, a->zn);
++    zm = vec_full_reg_ptr(s, a->zm);
++    pn = pred_full_reg_ptr(s, a->pn);
++    pm = pred_full_reg_ptr(s, a->pm);
++
++    fn(za, zn, zm, pn, pm, tcg_env, tcg_constant_i32(desc));
++    return true;
++}
++
++TRANS_FEAT(FMOPA_h, aa64_sme, do_outprod_env, a,
++           MO_32, gen_helper_sme_fmopa_h)
+ TRANS_FEAT(FMOPA_s, aa64_sme, do_outprod_fpst, a,
+            MO_32, FPST_FPCR, gen_helper_sme_fmopa_s)
+ TRANS_FEAT(FMOPA_d, aa64_sme_f64f64, do_outprod_fpst, a,

debian/patches/extra/0027-intel_iommu-fix-FRCD-construction-macro.patch

@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Cl=C3=A9ment=20Mathieu--Drif?=
+ <clement.mathieu--drif@eviden.com>
+Date: Tue, 9 Jul 2024 14:26:08 +0000
+Subject: [PATCH] intel_iommu: fix FRCD construction macro
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The constant must be unsigned, otherwise the two's complement
+overrides the other fields when a PASID is present.
+
+Fixes: 1b2b12376c8a ("intel-iommu: PASID support")
+Signed-off-by: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>
+Reviewed-by: Yi Liu <yi.l.liu@intel.com>
+Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
+Reviewed-by: Minwoo Im <minwoo.im@samsung.com>
+Message-Id: <20240709142557.317271-2-clement.mathieu--drif@eviden.com>
+Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
+Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+(cherry picked from commit a3c8d7e38550c3d5a46e6fa94ffadfa625a4861d)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ hw/i386/intel_iommu_internal.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
+index f8cf99bddf..cbc4030031 100644
+--- a/hw/i386/intel_iommu_internal.h
++++ b/hw/i386/intel_iommu_internal.h
+@@ -267,7 +267,7 @@
+ /* For the low 64-bit of 128-bit */
+ #define VTD_FRCD_FI(val)        ((val) & ~0xfffULL)
+ #define VTD_FRCD_PV(val)        (((val) & 0xffffULL) << 40)
+-#define VTD_FRCD_PP(val)        (((val) & 0x1) << 31)
++#define VTD_FRCD_PP(val)        (((val) & 0x1ULL) << 31)
+ #define VTD_FRCD_IR_IDX(val)    (((val) & 0xffffULL) << 48)
+ 
+ /* DMA Remapping Fault Conditions */

debian/patches/extra/0028-target-i386-Do-not-apply-REX-to-MMX-operands.patch

@@ -0,0 +1,33 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Richard Henderson <richard.henderson@linaro.org>
+Date: Mon, 12 Aug 2024 12:58:42 +1000
+Subject: [PATCH] target/i386: Do not apply REX to MMX operands
+
+Cc: qemu-stable@nongnu.org
+Fixes: b3e22b2318a ("target/i386: add core of new i386 decoder")
+Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2495
+Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
+Link: https://lore.kernel.org/r/20240812025844.58956-2-richard.henderson@linaro.org
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+(cherry picked from commit 416f2b16c02c618c0f233372ebfe343f9ee667d4)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ target/i386/tcg/decode-new.c.inc | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/target/i386/tcg/decode-new.c.inc b/target/i386/tcg/decode-new.c.inc
+index 4209d59ca8..09b8d2314a 100644
+--- a/target/i386/tcg/decode-new.c.inc
++++ b/target/i386/tcg/decode-new.c.inc
+@@ -1271,7 +1271,10 @@ static bool decode_op(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode,
+             op->unit = X86_OP_SSE;
+         }
+     get_reg:
+-        op->n = ((get_modrm(s, env) >> 3) & 7) | REX_R(s);
++        op->n = ((get_modrm(s, env) >> 3) & 7);
++        if (op->unit != X86_OP_MMX) {
++            op->n |= REX_R(s);
++        }
+         break;
+ 
+     case X86_TYPE_E:  /* ALU modrm operand */

debian/patches/extra/0029-module-Prevent-crash-by-resetting-local_err-in-modul.patch

@@ -0,0 +1,42 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
+Date: Fri, 9 Aug 2024 14:13:40 +0200
+Subject: [PATCH] module: Prevent crash by resetting local_err in
+ module_load_qom_all()
+
+Set local_err to NULL after it has been freed in error_report_err(). This
+avoids triggering assert(*errp == NULL) failure in error_setv() when
+local_err is reused in the loop.
+
+Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
+Reviewed-by: Claudio Fontana <cfontana@suse.de>
+Reviewed-by: Denis V. Lunev <den@openvz.org>
+Link: https://lore.kernel.org/r/20240809121340.992049-2-alexander.ivanov@virtuozzo.com
+[Do the same by moving the declaration instead. - Paolo]
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+(cherry picked from commit 940d802b24e63650e0eacad3714e2ce171cba17c)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ util/module.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/util/module.c b/util/module.c
+index 32e263163c..3eb0f06df1 100644
+--- a/util/module.c
++++ b/util/module.c
+@@ -354,13 +354,13 @@ int module_load_qom(const char *type, Error **errp)
+ void module_load_qom_all(void)
+ {
+     const QemuModinfo *modinfo;
+-    Error *local_err = NULL;
+ 
+     if (module_loaded_qom_all) {
+         return;
+     }
+ 
+     for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
++        Error *local_err = NULL;
+         if (!modinfo->objs) {
+             continue;
+         }

debian/patches/extra/0030-nbd-server-Plumb-in-new-args-to-nbd_client_add.patch

@@ -0,0 +1,164 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Wed, 7 Aug 2024 08:50:01 -0500
+Subject: [PATCH] nbd/server: Plumb in new args to nbd_client_add()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Upcoming patches to fix a CVE need to track an opaque pointer passed
+in by the owner of a client object, as well as request for a time
+limit on how fast negotiation must complete.  Prepare for that by
+changing the signature of nbd_client_new() and adding an accessor to
+get at the opaque pointer, although for now the two servers
+(qemu-nbd.c and blockdev-nbd.c) do not change behavior even though
+they pass in a new default timeout value.
+
+Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-ID: <20240807174943.771624-11-eblake@redhat.com>
+Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
+[eblake: s/LIMIT/MAX_SECS/ as suggested by Dan]
+Signed-off-by: Eric Blake <eblake@redhat.com>
+(cherry picked from commit fb1c2aaa981e0a2fa6362c9985f1296b74f055ac)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ blockdev-nbd.c      |  6 ++++--
+ include/block/nbd.h | 11 ++++++++++-
+ nbd/server.c        | 20 +++++++++++++++++---
+ qemu-nbd.c          |  4 +++-
+ 4 files changed, 34 insertions(+), 7 deletions(-)
+
+diff --git a/blockdev-nbd.c b/blockdev-nbd.c
+index 213012435f..267a1de903 100644
+--- a/blockdev-nbd.c
++++ b/blockdev-nbd.c
+@@ -64,8 +64,10 @@ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
+     nbd_update_server_watch(nbd_server);
+ 
+     qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
+-    nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz,
+-                   nbd_blockdev_client_closed);
++    /* TODO - expose handshake timeout as QMP option */
++    nbd_client_new(cioc, NBD_DEFAULT_HANDSHAKE_MAX_SECS,
++                   nbd_server->tlscreds, nbd_server->tlsauthz,
++                   nbd_blockdev_client_closed, NULL);
+ }
+ 
+ static void nbd_update_server_watch(NBDServerData *s)
+diff --git a/include/block/nbd.h b/include/block/nbd.h
+index 4e7bd6342f..1d4d65922d 100644
+--- a/include/block/nbd.h
++++ b/include/block/nbd.h
+@@ -33,6 +33,12 @@ typedef struct NBDMetaContexts NBDMetaContexts;
+ 
+ extern const BlockExportDriver blk_exp_nbd;
+ 
++/*
++ * NBD_DEFAULT_HANDSHAKE_MAX_SECS: Number of seconds in which client must
++ * succeed at NBD_OPT_GO before being forcefully dropped as too slow.
++ */
++#define NBD_DEFAULT_HANDSHAKE_MAX_SECS 10
++
+ /* Handshake phase structs - this struct is passed on the wire */
+ 
+ typedef struct NBDOption {
+@@ -403,9 +409,12 @@ AioContext *nbd_export_aio_context(NBDExport *exp);
+ NBDExport *nbd_export_find(const char *name);
+ 
+ void nbd_client_new(QIOChannelSocket *sioc,
++                    uint32_t handshake_max_secs,
+                     QCryptoTLSCreds *tlscreds,
+                     const char *tlsauthz,
+-                    void (*close_fn)(NBDClient *, bool));
++                    void (*close_fn)(NBDClient *, bool),
++                    void *owner);
++void *nbd_client_owner(NBDClient *client);
+ void nbd_client_get(NBDClient *client);
+ void nbd_client_put(NBDClient *client);
+ 
+diff --git a/nbd/server.c b/nbd/server.c
+index 892797bb11..e50012499f 100644
+--- a/nbd/server.c
++++ b/nbd/server.c
+@@ -124,12 +124,14 @@ struct NBDMetaContexts {
+ struct NBDClient {
+     int refcount; /* atomic */
+     void (*close_fn)(NBDClient *client, bool negotiated);
++    void *owner;
+ 
+     QemuMutex lock;
+ 
+     NBDExport *exp;
+     QCryptoTLSCreds *tlscreds;
+     char *tlsauthz;
++    uint32_t handshake_max_secs;
+     QIOChannelSocket *sioc; /* The underlying data channel */
+     QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
+ 
+@@ -3191,6 +3193,7 @@ static coroutine_fn void nbd_co_client_start(void *opaque)
+ 
+     qemu_co_mutex_init(&client->send_lock);
+ 
++    /* TODO - utilize client->handshake_max_secs */
+     if (nbd_negotiate(client, &local_err)) {
+         if (local_err) {
+             error_report_err(local_err);
+@@ -3205,14 +3208,17 @@ static coroutine_fn void nbd_co_client_start(void *opaque)
+ }
+ 
+ /*
+- * Create a new client listener using the given channel @sioc.
++ * Create a new client listener using the given channel @sioc and @owner.
+  * Begin servicing it in a coroutine.  When the connection closes, call
+- * @close_fn with an indication of whether the client completed negotiation.
++ * @close_fn with an indication of whether the client completed negotiation
++ * within @handshake_max_secs seconds (0 for unbounded).
+  */
+ void nbd_client_new(QIOChannelSocket *sioc,
++                    uint32_t handshake_max_secs,
+                     QCryptoTLSCreds *tlscreds,
+                     const char *tlsauthz,
+-                    void (*close_fn)(NBDClient *, bool))
++                    void (*close_fn)(NBDClient *, bool),
++                    void *owner)
+ {
+     NBDClient *client;
+     Coroutine *co;
+@@ -3225,13 +3231,21 @@ void nbd_client_new(QIOChannelSocket *sioc,
+         object_ref(OBJECT(client->tlscreds));
+     }
+     client->tlsauthz = g_strdup(tlsauthz);
++    client->handshake_max_secs = handshake_max_secs;
+     client->sioc = sioc;
+     qio_channel_set_delay(QIO_CHANNEL(sioc), false);
+     object_ref(OBJECT(client->sioc));
+     client->ioc = QIO_CHANNEL(sioc);
+     object_ref(OBJECT(client->ioc));
+     client->close_fn = close_fn;
++    client->owner = owner;
+ 
+     co = qemu_coroutine_create(nbd_co_client_start, client);
+     qemu_coroutine_enter(co);
+ }
++
++void *
++nbd_client_owner(NBDClient *client)
++{
++    return client->owner;
++}
+diff --git a/qemu-nbd.c b/qemu-nbd.c
+index d7b3ccab21..48e2fa5858 100644
+--- a/qemu-nbd.c
++++ b/qemu-nbd.c
+@@ -390,7 +390,9 @@ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
+ 
+     nb_fds++;
+     nbd_update_server_watch();
+-    nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
++    /* TODO - expose handshake timeout as command line option */
++    nbd_client_new(cioc, NBD_DEFAULT_HANDSHAKE_MAX_SECS,
++                   tlscreds, tlsauthz, nbd_client_closed, NULL);
+ }
+ 
+ static void nbd_update_server_watch(void)

debian/patches/extra/0031-nbd-server-CVE-2024-7409-Cap-default-max-connections.patch

@@ -0,0 +1,172 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Tue, 6 Aug 2024 13:53:00 -0500
+Subject: [PATCH] nbd/server: CVE-2024-7409: Cap default max-connections to 100
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Allowing an unlimited number of clients to any web service is a recipe
+for a rudimentary denial of service attack: the client merely needs to
+open lots of sockets without closing them, until qemu no longer has
+any more fds available to allocate.
+
+For qemu-nbd, we default to allowing only 1 connection unless more are
+explicitly asked for (-e or --shared); this was historically picked as
+a nice default (without an explicit -t, a non-persistent qemu-nbd goes
+away after a client disconnects, without needing any additional
+follow-up commands), and we are not going to change that interface now
+(besides, someday we want to point people towards qemu-storage-daemon
+instead of qemu-nbd).
+
+But for qemu proper, and the newer qemu-storage-daemon, the QMP
+nbd-server-start command has historically had a default of unlimited
+number of connections, in part because unlike qemu-nbd it is
+inherently persistent until nbd-server-stop.  Allowing multiple client
+sockets is particularly useful for clients that can take advantage of
+MULTI_CONN (creating parallel sockets to increase throughput),
+although known clients that do so (such as libnbd's nbdcopy) typically
+use only 8 or 16 connections (the benefits of scaling diminish once
+more sockets are competing for kernel attention).  Picking a number
+large enough for typical use cases, but not unlimited, makes it
+slightly harder for a malicious client to perform a denial of service
+merely by opening lots of connections withot progressing through the
+handshake.
+
+This change does not eliminate CVE-2024-7409 on its own, but reduces
+the chance for fd exhaustion or unlimited memory usage as an attack
+surface.  On the other hand, by itself, it makes it more obvious that
+with a finite limit, we have the problem of an unauthenticated client
+holding 100 fds opened as a way to block out a legitimate client from
+being able to connect; thus, later patches will further add timeouts
+to reject clients that are not making progress.
+
+This is an INTENTIONAL change in behavior, and will break any client
+of nbd-server-start that was not passing an explicit max-connections
+parameter, yet expects more than 100 simultaneous connections.  We are
+not aware of any such client (as stated above, most clients aware of
+MULTI_CONN get by just fine on 8 or 16 connections, and probably cope
+with later connections failing by relying on the earlier connections;
+libvirt has not yet been passing max-connections, but generally
+creates NBD servers with the intent for a single client for the sake
+of live storage migration; meanwhile, the KubeSAN project anticipates
+a large cluster sharing multiple clients [up to 8 per node, and up to
+100 nodes in a cluster], but it currently uses qemu-nbd with an
+explicit --shared=0 rather than qemu-storage-daemon with
+nbd-server-start).
+
+We considered using a deprecation period (declare that omitting
+max-parameters is deprecated, and make it mandatory in 3 releases -
+then we don't need to pick an arbitrary default); that has zero risk
+of breaking any apps that accidentally depended on more than 100
+connections, and where such breakage might not be noticed under unit
+testing but only under the larger loads of production usage.  But it
+does not close the denial-of-service hole until far into the future,
+and requires all apps to change to add the parameter even if 100 was
+good enough.  It also has a drawback that any app (like libvirt) that
+is accidentally relying on an unlimited default should seriously
+consider their own CVE now, at which point they are going to change to
+pass explicit max-connections sooner than waiting for 3 qemu releases.
+Finally, if our changed default breaks an app, that app can always
+pass in an explicit max-parameters with a larger value.
+
+It is also intentional that the HMP interface to nbd-server-start is
+not changed to expose max-connections (any client needing to fine-tune
+things should be using QMP).
+
+Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-ID: <20240807174943.771624-12-eblake@redhat.com>
+Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
+[ericb: Expand commit message to summarize Dan's argument for why we
+break corner-case back-compat behavior without a deprecation period]
+Signed-off-by: Eric Blake <eblake@redhat.com>
+(cherry picked from commit c8a76dbd90c2f48df89b75bef74917f90a59b623)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ block/monitor/block-hmp-cmds.c | 3 ++-
+ blockdev-nbd.c                 | 8 ++++++++
+ include/block/nbd.h            | 7 +++++++
+ qapi/block-export.json         | 4 ++--
+ 4 files changed, 19 insertions(+), 3 deletions(-)
+
+diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
+index d954bec6f1..bdf2eb50b6 100644
+--- a/block/monitor/block-hmp-cmds.c
++++ b/block/monitor/block-hmp-cmds.c
+@@ -402,7 +402,8 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict)
+         goto exit;
+     }
+ 
+-    nbd_server_start(addr, NULL, NULL, 0, &local_err);
++    nbd_server_start(addr, NULL, NULL, NBD_DEFAULT_MAX_CONNECTIONS,
++                     &local_err);
+     qapi_free_SocketAddress(addr);
+     if (local_err != NULL) {
+         goto exit;
+diff --git a/blockdev-nbd.c b/blockdev-nbd.c
+index 267a1de903..24ba5382db 100644
+--- a/blockdev-nbd.c
++++ b/blockdev-nbd.c
+@@ -170,6 +170,10 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds,
+ 
+ void nbd_server_start_options(NbdServerOptions *arg, Error **errp)
+ {
++    if (!arg->has_max_connections) {
++        arg->max_connections = NBD_DEFAULT_MAX_CONNECTIONS;
++    }
++
+     nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz,
+                      arg->max_connections, errp);
+ }
+@@ -182,6 +186,10 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
+ {
+     SocketAddress *addr_flat = socket_address_flatten(addr);
+ 
++    if (!has_max_connections) {
++        max_connections = NBD_DEFAULT_MAX_CONNECTIONS;
++    }
++
+     nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp);
+     qapi_free_SocketAddress(addr_flat);
+ }
+diff --git a/include/block/nbd.h b/include/block/nbd.h
+index 1d4d65922d..d4f8b21aec 100644
+--- a/include/block/nbd.h
++++ b/include/block/nbd.h
+@@ -39,6 +39,13 @@ extern const BlockExportDriver blk_exp_nbd;
+  */
+ #define NBD_DEFAULT_HANDSHAKE_MAX_SECS 10
+ 
++/*
++ * NBD_DEFAULT_MAX_CONNECTIONS: Number of client sockets to allow at
++ * once; must be large enough to allow a MULTI_CONN-aware client like
++ * nbdcopy to create its typical number of 8-16 sockets.
++ */
++#define NBD_DEFAULT_MAX_CONNECTIONS 100
++
+ /* Handshake phase structs - this struct is passed on the wire */
+ 
+ typedef struct NBDOption {
+diff --git a/qapi/block-export.json b/qapi/block-export.json
+index 3919a2d5b9..f45e4fd481 100644
+--- a/qapi/block-export.json
++++ b/qapi/block-export.json
+@@ -28,7 +28,7 @@
+ # @max-connections: The maximum number of connections to allow at the
+ #     same time, 0 for unlimited.  Setting this to 1 also stops the
+ #     server from advertising multiple client support (since 5.2;
+-#     default: 0)
++#     default: 100)
+ #
+ # Since: 4.2
+ ##
+@@ -63,7 +63,7 @@
+ # @max-connections: The maximum number of connections to allow at the
+ #     same time, 0 for unlimited.  Setting this to 1 also stops the
+ #     server from advertising multiple client support (since 5.2;
+-#     default: 0).
++#     default: 100).
+ #
+ # Errors:
+ #     - if the server is already running

debian/patches/extra/0032-nbd-server-CVE-2024-7409-Drop-non-negotiating-client.patch

@@ -0,0 +1,123 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Thu, 8 Aug 2024 16:05:08 -0500
+Subject: [PATCH] nbd/server: CVE-2024-7409: Drop non-negotiating clients
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+A client that opens a socket but does not negotiate is merely hogging
+qemu's resources (an open fd and a small amount of memory); and a
+malicious client that can access the port where NBD is listening can
+attempt a denial of service attack by intentionally opening and
+abandoning lots of unfinished connections.  The previous patch put a
+default bound on the number of such ongoing connections, but once that
+limit is hit, no more clients can connect (including legitimate ones).
+The solution is to insist that clients complete handshake within a
+reasonable time limit, defaulting to 10 seconds.  A client that has
+not successfully completed NBD_OPT_GO by then (including the case of
+where the client didn't know TLS credentials to even reach the point
+of NBD_OPT_GO) is wasting our time and does not deserve to stay
+connected.  Later patches will allow fine-tuning the limit away from
+the default value (including disabling it for doing integration
+testing of the handshake process itself).
+
+Note that this patch in isolation actually makes it more likely to see
+qemu SEGV after nbd-server-stop, as any client socket still connected
+when the server shuts down will now be closed after 10 seconds rather
+than at the client's whims.  That will be addressed in the next patch.
+
+For a demo of this patch in action:
+$ qemu-nbd -f raw -r -t -e 10 file &
+$ nbdsh --opt-mode -c '
+H = list()
+for i in range(20):
+  print(i)
+  H.insert(i, nbd.NBD())
+  H[i].set_opt_mode(True)
+  H[i].connect_uri("nbd://localhost")
+'
+$ kill $!
+
+where later connections get to start progressing once earlier ones are
+forcefully dropped for taking too long, rather than hanging.
+
+Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-ID: <20240807174943.771624-13-eblake@redhat.com>
+Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
+[eblake: rebase to changes earlier in series, reduce scope of timer]
+Signed-off-by: Eric Blake <eblake@redhat.com>
+(cherry picked from commit b9b72cb3ce15b693148bd09cef7e50110566d8a0)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ nbd/server.c     | 28 +++++++++++++++++++++++++++-
+ nbd/trace-events |  1 +
+ 2 files changed, 28 insertions(+), 1 deletion(-)
+
+diff --git a/nbd/server.c b/nbd/server.c
+index e50012499f..39285cc971 100644
+--- a/nbd/server.c
++++ b/nbd/server.c
+@@ -3186,22 +3186,48 @@ static void nbd_client_receive_next_request(NBDClient *client)
+     }
+ }
+ 
++static void nbd_handshake_timer_cb(void *opaque)
++{
++    QIOChannel *ioc = opaque;
++
++    trace_nbd_handshake_timer_cb();
++    qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
++}
++
+ static coroutine_fn void nbd_co_client_start(void *opaque)
+ {
+     NBDClient *client = opaque;
+     Error *local_err = NULL;
++    QEMUTimer *handshake_timer = NULL;
+ 
+     qemu_co_mutex_init(&client->send_lock);
+ 
+-    /* TODO - utilize client->handshake_max_secs */
++    /*
++     * Create a timer to bound the time spent in negotiation. If the
++     * timer expires, it is likely nbd_negotiate will fail because the
++     * socket was shutdown.
++     */
++    if (client->handshake_max_secs > 0) {
++        handshake_timer = aio_timer_new(qemu_get_aio_context(),
++                                        QEMU_CLOCK_REALTIME,
++                                        SCALE_NS,
++                                        nbd_handshake_timer_cb,
++                                        client->sioc);
++        timer_mod(handshake_timer,
++                  qemu_clock_get_ns(QEMU_CLOCK_REALTIME) +
++                  client->handshake_max_secs * NANOSECONDS_PER_SECOND);
++    }
++
+     if (nbd_negotiate(client, &local_err)) {
+         if (local_err) {
+             error_report_err(local_err);
+         }
++        timer_free(handshake_timer);
+         client_close(client, false);
+         return;
+     }
+ 
++    timer_free(handshake_timer);
+     WITH_QEMU_LOCK_GUARD(&client->lock) {
+         nbd_client_receive_next_request(client);
+     }
+diff --git a/nbd/trace-events b/nbd/trace-events
+index 00ae3216a1..cbd0a4ab7e 100644
+--- a/nbd/trace-events
++++ b/nbd/trace-events
+@@ -76,6 +76,7 @@ nbd_co_receive_request_payload_received(uint64_t cookie, uint64_t len) "Payload
+ nbd_co_receive_ext_payload_compliance(uint64_t from, uint64_t len) "client sent non-compliant write without payload flag: from=0x%" PRIx64 ", len=0x%" PRIx64
+ nbd_co_receive_align_compliance(const char *op, uint64_t from, uint64_t len, uint32_t align) "client sent non-compliant unaligned %s request: from=0x%" PRIx64 ", len=0x%" PRIx64 ", align=0x%" PRIx32
+ nbd_trip(void) "Reading request"
++nbd_handshake_timer_cb(void) "client took too long to negotiate"
+ 
+ # client-connection.c
+ nbd_connect_thread_sleep(uint64_t timeout) "timeout %" PRIu64

debian/patches/extra/0033-nbd-server-CVE-2024-7409-Close-stray-clients-at-serv.patch

@@ -0,0 +1,161 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Wed, 7 Aug 2024 12:23:13 -0500
+Subject: [PATCH] nbd/server: CVE-2024-7409: Close stray clients at server-stop
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+A malicious client can attempt to connect to an NBD server, and then
+intentionally delay progress in the handshake, including if it does
+not know the TLS secrets.  Although the previous two patches reduce
+this behavior by capping the default max-connections parameter and
+killing slow clients, they did not eliminate the possibility of a
+client waiting to close the socket until after the QMP nbd-server-stop
+command is executed, at which point qemu would SEGV when trying to
+dereference the NULL nbd_server global which is no longer present.
+This amounts to a denial of service attack.  Worse, if another NBD
+server is started before the malicious client disconnects, I cannot
+rule out additional adverse effects when the old client interferes
+with the connection count of the new server (although the most likely
+is a crash due to an assertion failure when checking
+nbd_server->connections > 0).
+
+For environments without this patch, the CVE can be mitigated by
+ensuring (such as via a firewall) that only trusted clients can
+connect to an NBD server.  Note that using frameworks like libvirt
+that ensure that TLS is used and that nbd-server-stop is not executed
+while any trusted clients are still connected will only help if there
+is also no possibility for an untrusted client to open a connection
+but then stall on the NBD handshake.
+
+Given the previous patches, it would be possible to guarantee that no
+clients remain connected by having nbd-server-stop sleep for longer
+than the default handshake deadline before finally freeing the global
+nbd_server object, but that could make QMP non-responsive for a long
+time.  So intead, this patch fixes the problem by tracking all client
+sockets opened while the server is running, and forcefully closing any
+such sockets remaining without a completed handshake at the time of
+nbd-server-stop, then waiting until the coroutines servicing those
+sockets notice the state change.  nbd-server-stop now has a second
+AIO_WAIT_WHILE_UNLOCKED (the first is indirectly through the
+blk_exp_close_all_type() that disconnects all clients that completed
+handshakes), but forced socket shutdown is enough to progress the
+coroutines and quickly tear down all clients before the server is
+freed, thus finally fixing the CVE.
+
+This patch relies heavily on the fact that nbd/server.c guarantees
+that it only calls nbd_blockdev_client_closed() from the main loop
+(see the assertion in nbd_client_put() and the hoops used in
+nbd_client_put_nonzero() to achieve that); if we did not have that
+guarantee, we would also need a mutex protecting our accesses of the
+list of connections to survive re-entrancy from independent iothreads.
+
+Although I did not actually try to test old builds, it looks like this
+problem has existed since at least commit 862172f45c (v2.12.0, 2017) -
+even back when that patch started using a QIONetListener to handle
+listening on multiple sockets, nbd_server_free() was already unaware
+that the nbd_blockdev_client_closed callback can be reached later by a
+client thread that has not completed handshakes (and therefore the
+client's socket never got added to the list closed in
+nbd_export_close_all), despite that patch intentionally tearing down
+the QIONetListener to prevent new clients.
+
+Reported-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
+Fixes: CVE-2024-7409
+CC: qemu-stable@nongnu.org
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-ID: <20240807174943.771624-14-eblake@redhat.com>
+Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
+(cherry picked from commit 3e7ef738c8462c45043a1d39f702a0990406a3b3)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ blockdev-nbd.c | 35 ++++++++++++++++++++++++++++++++++-
+ 1 file changed, 34 insertions(+), 1 deletion(-)
+
+diff --git a/blockdev-nbd.c b/blockdev-nbd.c
+index 24ba5382db..f73409ae49 100644
+--- a/blockdev-nbd.c
++++ b/blockdev-nbd.c
+@@ -21,12 +21,18 @@
+ #include "io/channel-socket.h"
+ #include "io/net-listener.h"
+ 
++typedef struct NBDConn {
++    QIOChannelSocket *cioc;
++    QLIST_ENTRY(NBDConn) next;
++} NBDConn;
++
+ typedef struct NBDServerData {
+     QIONetListener *listener;
+     QCryptoTLSCreds *tlscreds;
+     char *tlsauthz;
+     uint32_t max_connections;
+     uint32_t connections;
++    QLIST_HEAD(, NBDConn) conns;
+ } NBDServerData;
+ 
+ static NBDServerData *nbd_server;
+@@ -51,6 +57,14 @@ int nbd_server_max_connections(void)
+ 
+ static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
+ {
++    NBDConn *conn = nbd_client_owner(client);
++
++    assert(qemu_in_main_thread() && nbd_server);
++
++    object_unref(OBJECT(conn->cioc));
++    QLIST_REMOVE(conn, next);
++    g_free(conn);
++
+     nbd_client_put(client);
+     assert(nbd_server->connections > 0);
+     nbd_server->connections--;
+@@ -60,14 +74,20 @@ static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
+ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
+                        gpointer opaque)
+ {
++    NBDConn *conn = g_new0(NBDConn, 1);
++
++    assert(qemu_in_main_thread() && nbd_server);
+     nbd_server->connections++;
++    object_ref(OBJECT(cioc));
++    conn->cioc = cioc;
++    QLIST_INSERT_HEAD(&nbd_server->conns, conn, next);
+     nbd_update_server_watch(nbd_server);
+ 
+     qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
+     /* TODO - expose handshake timeout as QMP option */
+     nbd_client_new(cioc, NBD_DEFAULT_HANDSHAKE_MAX_SECS,
+                    nbd_server->tlscreds, nbd_server->tlsauthz,
+-                   nbd_blockdev_client_closed, NULL);
++                   nbd_blockdev_client_closed, conn);
+ }
+ 
+ static void nbd_update_server_watch(NBDServerData *s)
+@@ -81,12 +101,25 @@ static void nbd_update_server_watch(NBDServerData *s)
+ 
+ static void nbd_server_free(NBDServerData *server)
+ {
++    NBDConn *conn, *tmp;
++
+     if (!server) {
+         return;
+     }
+ 
++    /*
++     * Forcefully close the listener socket, and any clients that have
++     * not yet disconnected on their own.
++     */
+     qio_net_listener_disconnect(server->listener);
+     object_unref(OBJECT(server->listener));
++    QLIST_FOREACH_SAFE(conn, &server->conns, next, tmp) {
++        qio_channel_shutdown(QIO_CHANNEL(conn->cioc), QIO_CHANNEL_SHUTDOWN_BOTH,
++                             NULL);
++    }
++
++    AIO_WAIT_WHILE_UNLOCKED(NULL, server->connections > 0);
++
+     if (server->tlscreds) {
+         object_unref(OBJECT(server->tlscreds));
+     }

debian/patches/extra/0034-vnc-fix-crash-when-no-console-attached.patch

@@ -0,0 +1,47 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
+Date: Tue, 20 Aug 2024 17:11:12 +0400
+Subject: [PATCH] vnc: fix crash when no console attached
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Since commit e99441a3793b5 ("ui/curses: Do not use console_select()")
+qemu_text_console_put_keysym() no longer checks for NULL console
+argument, which leads to a later crash:
+
+Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
+0x00005555559ee186 in qemu_text_console_handle_keysym (s=0x0, keysym=31) at ../ui/console-vc.c:332
+332	        } else if (s->echo && (keysym == '\r' || keysym == '\n')) {
+(gdb) bt
+ #0  0x00005555559ee186 in qemu_text_console_handle_keysym (s=0x0, keysym=31) at ../ui/console-vc.c:332
+ #1  0x00005555559e18e5 in qemu_text_console_put_keysym (s=<optimized out>, keysym=<optimized out>) at ../ui/console.c:303
+ #2  0x00005555559f2e88 in do_key_event (vs=vs@entry=0x5555579045c0, down=down@entry=1, keycode=keycode@entry=60, sym=sym@entry=65471) at ../ui/vnc.c:2034
+ #3  0x00005555559f845c in ext_key_event (vs=0x5555579045c0, down=1, sym=65471, keycode=<optimized out>) at ../ui/vnc.c:2070
+ #4  protocol_client_msg (vs=0x5555579045c0, data=<optimized out>, len=<optimized out>) at ../ui/vnc.c:2514
+ #5  0x00005555559f515c in vnc_client_read (vs=0x5555579045c0) at ../ui/vnc.c:1607
+
+Fixes: e99441a3793b5 ("ui/curses: Do not use console_select()")
+Fixes: https://issues.redhat.com/browse/RHEL-50529
+Cc: qemu-stable@nongnu.org
+Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
+(picked from https://lore.kernel.org/qemu-devel/20240820131112.1267954-1-marcandre.lureau@redhat.com/)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ ui/vnc.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/ui/vnc.c b/ui/vnc.c
+index b3fd78022b..953ea38318 100644
+--- a/ui/vnc.c
++++ b/ui/vnc.c
+@@ -1935,7 +1935,7 @@ static void do_key_event(VncState *vs, int down, int keycode, int sym)
+     }
+ 
+     qkbd_state_key_event(vs->vd->kbd, qcode, down);
+-    if (!qemu_console_is_graphic(vs->vd->dcl.con)) {
++    if (QEMU_IS_TEXT_CONSOLE(vs->vd->dcl.con)) {
+         QemuTextConsole *con = QEMU_TEXT_CONSOLE(vs->vd->dcl.con);
+         bool numlock = qkbd_state_modifier_get(vs->vd->kbd, QKBD_MOD_NUMLOCK);
+         bool control = qkbd_state_modifier_get(vs->vd->kbd, QKBD_MOD_CTRL);

debian/patches/extra/0035-nbd-server-CVE-2024-7409-Avoid-use-after-free-when-c.patch

@@ -0,0 +1,89 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Thu, 22 Aug 2024 09:35:29 -0500
+Subject: [PATCH] nbd/server: CVE-2024-7409: Avoid use-after-free when closing
+ server
+
+Commit 3e7ef738 plugged the use-after-free of the global nbd_server
+object, but overlooked a use-after-free of nbd_server->listener.
+Although this race is harder to hit, notice that our shutdown path
+first drops the reference count of nbd_server->listener, then triggers
+actions that can result in a pending client reaching the
+nbd_blockdev_client_closed() callback, which in turn calls
+qio_net_listener_set_client_func on a potentially stale object.
+
+If we know we don't want any more clients to connect, and have already
+told the listener socket to shut down, then we should not be trying to
+update the listener socket's associated function.
+
+Reproducer:
+
+> #!/usr/bin/python3
+>
+> import os
+> from threading import Thread
+>
+> def start_stop():
+>     while 1:
+>         os.system('virsh qemu-monitor-command VM \'{"execute": "nbd-server-start",
++"arguments":{"addr":{"type":"unix","data":{"path":"/tmp/nbd-sock"}}}}\'')
+>         os.system('virsh qemu-monitor-command VM \'{"execute": "nbd-server-stop"}\'')
+>
+> def nbd_list():
+>     while 1:
+>         os.system('/path/to/build/qemu-nbd -L -k /tmp/nbd-sock')
+>
+> def test():
+>     sst = Thread(target=start_stop)
+>     sst.start()
+>     nlt = Thread(target=nbd_list)
+>     nlt.start()
+>
+>     sst.join()
+>     nlt.join()
+>
+> test()
+
+Fixes: CVE-2024-7409
+Fixes: 3e7ef738c8 ("nbd/server: CVE-2024-7409: Close stray clients at server-stop")
+CC: qemu-stable@nongnu.org
+Reported-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-ID: <20240822143617.800419-2-eblake@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+(cherry picked from commit 3874f5f73c441c52f1c699c848d463b0eda01e4c)
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ blockdev-nbd.c | 12 ++++++++----
+ 1 file changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/blockdev-nbd.c b/blockdev-nbd.c
+index f73409ae49..b36f41b7c5 100644
+--- a/blockdev-nbd.c
++++ b/blockdev-nbd.c
+@@ -92,10 +92,13 @@ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
+ 
+ static void nbd_update_server_watch(NBDServerData *s)
+ {
+-    if (!s->max_connections || s->connections < s->max_connections) {
+-        qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL);
+-    } else {
+-        qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL);
++    if (s->listener) {
++        if (!s->max_connections || s->connections < s->max_connections) {
++            qio_net_listener_set_client_func(s->listener, nbd_accept, NULL,
++                                             NULL);
++        } else {
++            qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL);
++        }
+     }
+ }
+ 
+@@ -113,6 +116,7 @@ static void nbd_server_free(NBDServerData *server)
+      */
+     qio_net_listener_disconnect(server->listener);
+     object_unref(OBJECT(server->listener));
++    server->listener = NULL;
+     QLIST_FOREACH_SAFE(conn, &server->conns, next, tmp) {
+         qio_channel_shutdown(QIO_CHANNEL(conn->cioc), QIO_CHANNEL_SHUTDOWN_BOTH,
+                              NULL);

debian/patches/extra/0036-softmmu-physmem-fix-memory-leak-in-dirty_memory_exte.patch

@@ -0,0 +1,134 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: David Hildenbrand <david@redhat.com>
+Date: Wed, 28 Aug 2024 11:07:43 +0200
+Subject: [PATCH] softmmu/physmem: fix memory leak in dirty_memory_extend()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+As reported by Peter, we might be leaking memory when removing the
+highest RAMBlock (in the weird ram_addr_t space), and adding a new one.
+
+We will fail to realize that we already allocated bitmaps for more
+dirty memory blocks, and effectively discard the pointers to them.
+
+Fix it by getting rid of last_ram_page() and by remembering the number
+of dirty memory blocks that have been allocated already.
+
+While at it, let's use "unsigned int" for the number of blocks, which
+should be sufficient until we reach ~32 exabytes.
+
+Looks like this leak was introduced as we switched from using a single
+bitmap_zero_extend() to allocating multiple bitmaps:
+bitmap_zero_extend() relies on g_renew() which should have taken care of
+this.
+
+Resolves: https://lkml.kernel.org/r/CAFEAcA-k7a+VObGAfCFNygQNfCKL=AfX6A4kScq=VSSK0peqPg@mail.gmail.com
+Reported-by: Peter Maydell <peter.maydell@linaro.org>
+Fixes: 5b82b703b69a ("memory: RCU ram_list.dirty_memory[] for safe RAM hotplug")
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Peter Xu <peterx@redhat.com>
+Tested-by: Peter Maydell <peter.maydell@linaro.org>
+Cc: qemu-stable@nongnu.org
+Cc: Stefan Hajnoczi <stefanha@redhat.com>
+Cc: Paolo Bonzini <pbonzini@redhat.com>
+Cc: Peter Xu <peterx@redhat.com>
+Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>
+Signed-off-by: David Hildenbrand <david@redhat.com>
+(picked from https://lore.kernel.org/qemu-devel/20240828090743.128647-1-david@redhat.com/)
+[FE: backport - remove not-yet-existing variable in context of hunk touching ram_block_add()]
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ include/exec/ramlist.h |  1 +
+ system/physmem.c       | 35 +++++++++--------------------------
+ 2 files changed, 10 insertions(+), 26 deletions(-)
+
+diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
+index 2ad2a81acc..d9cfe530be 100644
+--- a/include/exec/ramlist.h
++++ b/include/exec/ramlist.h
+@@ -50,6 +50,7 @@ typedef struct RAMList {
+     /* RCU-enabled, writes protected by the ramlist lock. */
+     QLIST_HEAD(, RAMBlock) blocks;
+     DirtyMemoryBlocks *dirty_memory[DIRTY_MEMORY_NUM];
++    unsigned int num_dirty_blocks;
+     uint32_t version;
+     QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
+ } RAMList;
+diff --git a/system/physmem.c b/system/physmem.c
+index a4fe3d2bf8..78f7db1121 100644
+--- a/system/physmem.c
++++ b/system/physmem.c
+@@ -1497,18 +1497,6 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
+     return offset;
+ }
+ 
+-static unsigned long last_ram_page(void)
+-{
+-    RAMBlock *block;
+-    ram_addr_t last = 0;
+-
+-    RCU_READ_LOCK_GUARD();
+-    RAMBLOCK_FOREACH(block) {
+-        last = MAX(last, block->offset + block->max_length);
+-    }
+-    return last >> TARGET_PAGE_BITS;
+-}
+-
+ static void qemu_ram_setup_dump(void *addr, ram_addr_t size)
+ {
+     int ret;
+@@ -1762,13 +1750,11 @@ void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length)
+ }
+ 
+ /* Called with ram_list.mutex held */
+-static void dirty_memory_extend(ram_addr_t old_ram_size,
+-                                ram_addr_t new_ram_size)
++static void dirty_memory_extend(ram_addr_t new_ram_size)
+ {
+-    ram_addr_t old_num_blocks = DIV_ROUND_UP(old_ram_size,
+-                                             DIRTY_MEMORY_BLOCK_SIZE);
+-    ram_addr_t new_num_blocks = DIV_ROUND_UP(new_ram_size,
+-                                             DIRTY_MEMORY_BLOCK_SIZE);
++    unsigned int old_num_blocks = ram_list.num_dirty_blocks;
++    unsigned int new_num_blocks = DIV_ROUND_UP(new_ram_size,
++                                               DIRTY_MEMORY_BLOCK_SIZE);
+     int i;
+ 
+     /* Only need to extend if block count increased */
+@@ -1800,6 +1786,8 @@ static void dirty_memory_extend(ram_addr_t old_ram_size,
+             g_free_rcu(old_blocks, rcu);
+         }
+     }
++
++    ram_list.num_dirty_blocks = new_num_blocks;
+ }
+ 
+ static void ram_block_add(RAMBlock *new_block, Error **errp)
+@@ -1808,11 +1796,9 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
+     const bool shared = qemu_ram_is_shared(new_block);
+     RAMBlock *block;
+     RAMBlock *last_block = NULL;
+-    ram_addr_t old_ram_size, new_ram_size;
++    ram_addr_t ram_size;
+     Error *err = NULL;
+ 
+-    old_ram_size = last_ram_page();
+-
+     qemu_mutex_lock_ramlist();
+     new_block->offset = find_ram_offset(new_block->max_length);
+ 
+@@ -1840,11 +1826,8 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
+         }
+     }
+ 
+-    new_ram_size = MAX(old_ram_size,
+-              (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS);
+-    if (new_ram_size > old_ram_size) {
+-        dirty_memory_extend(old_ram_size, new_ram_size);
+-    }
++    ram_size = (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS;
++    dirty_memory_extend(ram_size);
+     /* Keep the list sorted from biggest to smallest block.  Unlike QTAILQ,
+      * QLIST (which has an RCU-friendly variant) does not have insertion at
+      * tail, so save the last element in last_block.

debian/patches/extra/0037-block-reqlist-allow-adding-overlapping-requests.patch

@@ -0,0 +1,104 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fiona Ebner <f.ebner@proxmox.com>
+Date: Thu, 7 Nov 2024 17:51:13 +0100
+Subject: [PATCH] block/reqlist: allow adding overlapping requests
+
+Allow overlapping request by removing the assert that made it
+impossible. There are only two callers:
+
+1. block_copy_task_create()
+
+It already asserts the very same condition before calling
+reqlist_init_req().
+
+2. cbw_snapshot_read_lock()
+
+There is no need to have read requests be non-overlapping in
+copy-before-write when used for snapshot-access. In fact, there was no
+protection against two callers of cbw_snapshot_read_lock() calling
+reqlist_init_req() with overlapping ranges and this could lead to an
+assertion failure [1].
+
+In particular, with the reproducer script below [0], two
+cbw_co_snapshot_block_status() callers could race, with the second
+calling reqlist_init_req() before the first one finishes and removes
+its conflicting request.
+
+[0]:
+
+> #!/bin/bash -e
+> dd if=/dev/urandom of=/tmp/disk.raw bs=1M count=1024
+> ./qemu-img create /tmp/fleecing.raw -f raw 1G
+> (
+> ./qemu-system-x86_64 --qmp stdio \
+> --blockdev raw,node-name=node0,file.driver=file,file.filename=/tmp/disk.raw \
+> --blockdev raw,node-name=node1,file.driver=file,file.filename=/tmp/fleecing.raw \
+> <<EOF
+> {"execute": "qmp_capabilities"}
+> {"execute": "blockdev-add", "arguments": { "driver": "copy-before-write", "file": "node0", "target": "node1", "node-name": "node3" } }
+> {"execute": "blockdev-add", "arguments": { "driver": "snapshot-access", "file": "node3", "node-name": "snap0" } }
+> {"execute": "nbd-server-start", "arguments": {"addr": { "type": "unix", "data": { "path": "/tmp/nbd.socket" } } } }
+> {"execute": "block-export-add", "arguments": {"id": "exp0", "node-name": "snap0", "type": "nbd", "name": "exp0"}}
+> EOF
+> ) &
+> sleep 5
+> while true; do
+> ./qemu-nbd -d /dev/nbd0
+> ./qemu-nbd -c /dev/nbd0 nbd:unix:/tmp/nbd.socket:exportname=exp0 -f raw -r
+> nbdinfo --map 'nbd+unix:///exp0?socket=/tmp/nbd.socket'
+> done
+
+[1]:
+
+> #5  0x000071e5f0088eb2 in __GI___assert_fail (...) at ./assert/assert.c:101
+> #6  0x0000615285438017 in reqlist_init_req (...) at ../block/reqlist.c:23
+> #7  0x00006152853e2d98 in cbw_snapshot_read_lock (...) at ../block/copy-before-write.c:237
+> #8  0x00006152853e3068 in cbw_co_snapshot_block_status (...) at ../block/copy-before-write.c:304
+> #9  0x00006152853f4d22 in bdrv_co_snapshot_block_status (...) at ../block/io.c:3726
+> #10 0x000061528543a63e in snapshot_access_co_block_status (...) at ../block/snapshot-access.c:48
+> #11 0x00006152853f1a0a in bdrv_co_do_block_status (...) at ../block/io.c:2474
+> #12 0x00006152853f2016 in bdrv_co_common_block_status_above (...) at ../block/io.c:2652
+> #13 0x00006152853f22cf in bdrv_co_block_status_above (...) at ../block/io.c:2732
+> #14 0x00006152853d9a86 in blk_co_block_status_above (...) at ../block/block-backend.c:1473
+> #15 0x000061528538da6c in blockstatus_to_extents (...) at ../nbd/server.c:2374
+> #16 0x000061528538deb1 in nbd_co_send_block_status (...) at ../nbd/server.c:2481
+> #17 0x000061528538f424 in nbd_handle_request (...) at ../nbd/server.c:2978
+> #18 0x000061528538f906 in nbd_trip (...) at ../nbd/server.c:3121
+> #19 0x00006152855a7caf in coroutine_trampoline (...) at ../util/coroutine-ucontext.c:175
+
+Cc: qemu-stable@nongnu.org
+Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
+---
+ block/copy-before-write.c | 3 ++-
+ block/reqlist.c           | 2 --
+ 2 files changed, 2 insertions(+), 3 deletions(-)
+
+diff --git a/block/copy-before-write.c b/block/copy-before-write.c
+index 8aba27a71d..3698b3bc60 100644
+--- a/block/copy-before-write.c
++++ b/block/copy-before-write.c
+@@ -65,7 +65,8 @@ typedef struct BDRVCopyBeforeWriteState {
+ 
+     /*
+      * @frozen_read_reqs: current read requests for fleecing user in bs->file
+-     * node. These areas must not be rewritten by guest.
++     * node. These areas must not be rewritten by guest. There can be multiple
++     * overlapping read requests.
+      */
+     BlockReqList frozen_read_reqs;
+ 
+diff --git a/block/reqlist.c b/block/reqlist.c
+index 08cb57cfa4..098e807378 100644
+--- a/block/reqlist.c
++++ b/block/reqlist.c
+@@ -20,8 +20,6 @@
+ void reqlist_init_req(BlockReqList *reqs, BlockReq *req, int64_t offset,
+                       int64_t bytes)
+ {
+-    assert(!reqlist_find_conflict(reqs, offset, bytes));
+-
+     *req = (BlockReq) {
+         .offset = offset,
+         .bytes = bytes,

debian/patches/pve/0017-PVE-add-savevm-async-for-background-state-snapshots.patch

@@ -28,7 +28,8 @@ Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
      adapt to removal of QEMUFileOps
      improve condition for entering final stage
      adapt to QAPI and other changes for 8.2
-     make sure to not call vm_start() from coroutine]
+     make sure to not call vm_start() from coroutine
+     stop CPU throttling after finishing]
 Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
 ---
  hmp-commands-info.hx         |  13 +
@@ -36,13 +37,13 @@ Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
  include/migration/snapshot.h |   2 +
  include/monitor/hmp.h        |   3 +
  migration/meson.build        |   1 +
- migration/savevm-async.c     | 538 +++++++++++++++++++++++++++++++++++
+ migration/savevm-async.c     | 545 +++++++++++++++++++++++++++++++++++
  monitor/hmp-cmds.c           |  38 +++
  qapi/migration.json          |  34 +++
  qapi/misc.json               |  18 ++
  qemu-options.hx              |  12 +
  system/vl.c                  |  10 +
- 11 files changed, 686 insertions(+)
+ 11 files changed, 693 insertions(+)
  create mode 100644 migration/savevm-async.c
 
 diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
@@ -140,10 +141,10 @@ index 95d1cf2250..800f12a60d 100644
    'threadinfo.c',
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
 new file mode 100644
-index 0000000000..72cf6588c2
+index 0000000000..1af32604c7
 --- /dev/null
 +++ b/migration/savevm-async.c
-@@ -0,0 +1,538 @@
+@@ -0,0 +1,545 @@
 +#include "qemu/osdep.h"
 +#include "migration/channel-savevm-async.h"
 +#include "migration/migration.h"
@@ -154,6 +155,7 @@ index 0000000000..72cf6588c2
 +#include "migration/global_state.h"
 +#include "migration/ram.h"
 +#include "migration/qemu-file.h"
++#include "sysemu/cpu-throttle.h"
 +#include "sysemu/sysemu.h"
 +#include "sysemu/runstate.h"
 +#include "block/block.h"
@@ -342,6 +344,12 @@ index 0000000000..72cf6588c2
 +        ret || aborted ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED);
 +    ms->to_dst_file = NULL;
 +
++    /*
++     * Same as in migration_iteration_finish(): saving RAM might've turned on CPU throttling for
++     * auto-converge, make sure to disable it.
++     */
++    cpu_throttle_stop();
++
 +    qemu_savevm_state_cleanup();
 +
 +    ret = save_snapshot_cleanup();

debian/patches/pve/0018-PVE-add-optional-buffer-size-to-QEMUFile.patch

@@ -193,10 +193,10 @@ index 32fd4a34fd..36a0cd8cc8 100644
  
  /*
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
-index 72cf6588c2..fb4e8ea689 100644
+index 1af32604c7..be2035cd2e 100644
 --- a/migration/savevm-async.c
 +++ b/migration/savevm-async.c
-@@ -379,7 +379,7 @@ void qmp_savevm_start(const char *statefile, Error **errp)
+@@ -386,7 +386,7 @@ void qmp_savevm_start(const char *statefile, Error **errp)
  
      QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(snap_state.target,
                                                                 &snap_state.bs_pos));
@@ -205,7 +205,7 @@ index 72cf6588c2..fb4e8ea689 100644
  
      if (!snap_state.file) {
          error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
-@@ -503,7 +503,8 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
+@@ -510,7 +510,8 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
      blk_op_block_all(be, blocker);
  
      /* restore the VM state */

debian/patches/pve/0030-PVE-Backup-Proxmox-backup-patches-for-QEMU.patch

@@ -120,10 +120,10 @@ index e99914eaa4..6bba803f94 100644
  system_ss.add(when: 'CONFIG_TCG', if_true: files('blkreplay.c'))
  system_ss.add(files('block-ram-registrar.c'))
 diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
-index d954bec6f1..5000c084c5 100644
+index bdf2eb50b6..439a7a14c8 100644
 --- a/block/monitor/block-hmp-cmds.c
 +++ b/block/monitor/block-hmp-cmds.c
-@@ -1008,3 +1008,42 @@ void hmp_change_medium(Monitor *mon, const char *device, const char *target,
+@@ -1009,3 +1009,42 @@ void hmp_change_medium(Monitor *mon, const char *device, const char *target,
      qmp_blockdev_change_medium(device, NULL, target, arg, true, force,
                                 !!read_only, read_only_mode, errp);
  }

debian/patches/pve/0044-copy-before-write-allow-specifying-minimum-cluster-s.patch

@@ -82,10 +82,10 @@ index cc618e4561..12d662e9d4 100644
          return NULL;
      }
 diff --git a/block/copy-before-write.c b/block/copy-before-write.c
-index 853e01a1eb..47b3cdd09f 100644
+index 28f6a096cd..ef4e666303 100644
 --- a/block/copy-before-write.c
 +++ b/block/copy-before-write.c
-@@ -477,7 +477,8 @@ static int cbw_open(BlockDriverState *bs, QDict *options, int flags,
+@@ -478,7 +478,8 @@ static int cbw_open(BlockDriverState *bs, QDict *options, int flags,
  
      s->discard_source = flags & BDRV_O_CBW_DISCARD_SOURCE;
      s->bcs = block_copy_state_new(bs->file, s->target, bs, bitmap,

debian/patches/pve/0045-backup-add-minimum-cluster-size-to-performance-optio.patch

@@ -36,10 +36,10 @@ index 1963e47ab9..fe69723ada 100644
          goto error;
      }
 diff --git a/block/copy-before-write.c b/block/copy-before-write.c
-index 47b3cdd09f..bba58326d7 100644
+index ef4e666303..adb27649a8 100644
 --- a/block/copy-before-write.c
 +++ b/block/copy-before-write.c
-@@ -546,6 +546,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
+@@ -547,6 +547,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
                                    BlockDriverState *target,
                                    const char *filter_node_name,
                                    bool discard_source,
@@ -47,7 +47,7 @@ index 47b3cdd09f..bba58326d7 100644
                                    BlockCopyState **bcs,
                                    Error **errp)
  {
-@@ -564,6 +565,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
+@@ -565,6 +566,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
      }
      qdict_put_str(opts, "file", bdrv_get_node_name(source));
      qdict_put_str(opts, "target", bdrv_get_node_name(target));

debian/patches/pve/0046-PVE-backup-add-fleecing-option.patch

@@ -68,10 +68,10 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  3 files changed, 142 insertions(+), 4 deletions(-)
 
 diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
-index 5000c084c5..70b3de4c7e 100644
+index 439a7a14c8..d0e7771dcc 100644
 --- a/block/monitor/block-hmp-cmds.c
 +++ b/block/monitor/block-hmp-cmds.c
-@@ -1043,6 +1043,7 @@ void coroutine_fn hmp_backup(Monitor *mon, const QDict *qdict)
+@@ -1044,6 +1044,7 @@ void coroutine_fn hmp_backup(Monitor *mon, const QDict *qdict)
          NULL, NULL,
          devlist, qdict_haskey(qdict, "speed"), speed,
          false, 0, // BackupPerf max-workers

debian/patches/pve/0047-PVE-backup-improve-error-when-copy-before-write-fail.patch

@@ -21,7 +21,7 @@ Tested-by: Friedrich Weber <f.weber@proxmox.com>
  3 files changed, 22 insertions(+), 6 deletions(-)
 
 diff --git a/block/copy-before-write.c b/block/copy-before-write.c
-index bba58326d7..50cc4c7aae 100644
+index adb27649a8..a5bb4d14f6 100644
 --- a/block/copy-before-write.c
 +++ b/block/copy-before-write.c
 @@ -27,6 +27,7 @@
@@ -32,7 +32,7 @@ index bba58326d7..50cc4c7aae 100644
  #include "qemu/cutils.h"
  #include "qapi/error.h"
  #include "block/block_int.h"
-@@ -74,7 +75,8 @@ typedef struct BDRVCopyBeforeWriteState {
+@@ -75,7 +76,8 @@ typedef struct BDRVCopyBeforeWriteState {
       * @snapshot_error is normally zero. But on first copy-before-write failure
       * when @on_cbw_error == ON_CBW_ERROR_BREAK_SNAPSHOT, @snapshot_error takes
       * value of this error (<0). After that all in-flight and further
@@ -42,7 +42,7 @@ index bba58326d7..50cc4c7aae 100644
       */
      int snapshot_error;
  } BDRVCopyBeforeWriteState;
-@@ -114,7 +116,7 @@ static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
+@@ -115,7 +117,7 @@ static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
          return 0;
      }
  
@@ -51,7 +51,7 @@ index bba58326d7..50cc4c7aae 100644
          return 0;
      }
  
-@@ -138,9 +140,7 @@ static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
+@@ -139,9 +141,7 @@ static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs,
      WITH_QEMU_LOCK_GUARD(&s->lock) {
          if (ret < 0) {
              assert(s->on_cbw_error == ON_CBW_ERROR_BREAK_SNAPSHOT);
@@ -62,7 +62,7 @@ index bba58326d7..50cc4c7aae 100644
          } else {
              bdrv_set_dirty_bitmap(s->done_bitmap, off, end - off);
          }
-@@ -214,7 +214,7 @@ cbw_snapshot_read_lock(BlockDriverState *bs, int64_t offset, int64_t bytes,
+@@ -215,7 +215,7 @@ cbw_snapshot_read_lock(BlockDriverState *bs, int64_t offset, int64_t bytes,
  
      QEMU_LOCK_GUARD(&s->lock);
  
@@ -71,7 +71,7 @@ index bba58326d7..50cc4c7aae 100644
          g_free(req);
          return NULL;
      }
-@@ -585,6 +585,12 @@ void bdrv_cbw_drop(BlockDriverState *bs)
+@@ -586,6 +586,12 @@ void bdrv_cbw_drop(BlockDriverState *bs)
      bdrv_unref(bs);
  }
  

debian/patches/pve/0048-PVE-backup-fixup-error-handling-for-fleecing.patch

@@ -0,0 +1,103 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fiona Ebner <f.ebner@proxmox.com>
+Date: Thu, 7 Nov 2024 17:51:14 +0100
+Subject: [PATCH] PVE backup: fixup error handling for fleecing
+
+The drained section needs to be terminated before breaking out of the
+loop in the error scenarios. Otherwise, guest IO on the drive would
+become stuck.
+
+If the job is created successfully, then the job completion callback
+will clean up the snapshot access block nodes. In case failure
+happened before the job is created, there was no cleanup for the
+snapshot access block nodes yet. Add it.
+
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ pve-backup.c | 38 +++++++++++++++++++++++++-------------
+ 1 file changed, 25 insertions(+), 13 deletions(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index 4e730aa3da..c4178758b3 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -357,22 +357,23 @@ static void coroutine_fn pvebackup_co_complete_stream(void *opaque)
+     qemu_co_mutex_unlock(&backup_state.backup_mutex);
+ }
+ 
+-static void pvebackup_complete_cb(void *opaque, int ret)
++static void cleanup_snapshot_access(PVEBackupDevInfo *di)
+ {
+-    PVEBackupDevInfo *di = opaque;
+-    di->completed_ret = ret;
+-
+-    /*
+-     * Handle block-graph specific cleanup (for fleecing) outside of the coroutine, because the work
+-     * won't be done as a coroutine anyways:
+-     * - For snapshot_access, allows doing bdrv_unref() directly. Doing it via bdrv_co_unref() would
+-     *   just spawn a BH calling bdrv_unref().
+-     * - For cbw, draining would need to spawn a BH.
+-     */
+     if (di->fleecing.snapshot_access) {
+         bdrv_unref(di->fleecing.snapshot_access);
+         di->fleecing.snapshot_access = NULL;
+     }
++    if (di->fleecing.cbw) {
++        bdrv_cbw_drop(di->fleecing.cbw);
++        di->fleecing.cbw = NULL;
++    }
++}
++
++static void pvebackup_complete_cb(void *opaque, int ret)
++{
++    PVEBackupDevInfo *di = opaque;
++    di->completed_ret = ret;
++
+     if (di->fleecing.cbw) {
+         /*
+          * With fleecing, failure for cbw does not fail the guest write, but only sets the snapshot
+@@ -383,10 +384,17 @@ static void pvebackup_complete_cb(void *opaque, int ret)
+         if (di->completed_ret == -EACCES && snapshot_error) {
+             di->completed_ret = snapshot_error;
+         }
+-        bdrv_cbw_drop(di->fleecing.cbw);
+-        di->fleecing.cbw = NULL;
+     }
+ 
++    /*
++     * Handle block-graph specific cleanup (for fleecing) outside of the coroutine, because the work
++     * won't be done as a coroutine anyways:
++     * - For snapshot_access, allows doing bdrv_unref() directly. Doing it via bdrv_co_unref() would
++     *   just spawn a BH calling bdrv_unref().
++     * - For cbw, draining would need to spawn a BH.
++     */
++    cleanup_snapshot_access(di);
++
+     /*
+      * Needs to happen outside of coroutine, because it takes the graph write lock.
+      */
+@@ -587,6 +595,7 @@ static void create_backup_jobs_bh(void *opaque) {
+             if (!di->fleecing.cbw) {
+                 error_setg(errp, "appending cbw node for fleecing failed: %s",
+                            local_err ? error_get_pretty(local_err) : "unknown error");
++                bdrv_drained_end(di->bs);
+                 break;
+             }
+ 
+@@ -599,6 +608,8 @@ static void create_backup_jobs_bh(void *opaque) {
+             if (!di->fleecing.snapshot_access) {
+                 error_setg(errp, "setting up snapshot access for fleecing failed: %s",
+                            local_err ? error_get_pretty(local_err) : "unknown error");
++                cleanup_snapshot_access(di);
++                bdrv_drained_end(di->bs);
+                 break;
+             }
+             source_bs = di->fleecing.snapshot_access;
+@@ -637,6 +648,7 @@ static void create_backup_jobs_bh(void *opaque) {
+         }
+ 
+         if (!job || local_err) {
++            cleanup_snapshot_access(di);
+             error_setg(errp, "backup_job_create failed: %s",
+                        local_err ? error_get_pretty(local_err) : "null");
+             break;

debian/patches/pve/0049-PVE-backup-factor-out-setting-up-snapshot-access-for.patch

@@ -0,0 +1,135 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fiona Ebner <f.ebner@proxmox.com>
+Date: Thu, 7 Nov 2024 17:51:15 +0100
+Subject: [PATCH] PVE backup: factor out setting up snapshot access for
+ fleecing
+
+Avoids some line bloat in the create_backup_jobs_bh() function and is
+in preparation for setting up the snapshot access independently of
+fleecing, in particular that will be useful for providing access to
+the snapshot via NBD.
+
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ pve-backup.c | 95 ++++++++++++++++++++++++++++++++--------------------
+ 1 file changed, 58 insertions(+), 37 deletions(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index c4178758b3..051ebffe48 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -525,6 +525,62 @@ static int coroutine_fn pvebackup_co_add_config(
+     goto out;
+ }
+ 
++/*
++ * Setup a snapshot-access block node for a device with associated fleecing image.
++ */
++static int setup_snapshot_access(PVEBackupDevInfo *di, Error **errp)
++{
++    Error *local_err = NULL;
++
++    if (!di->fleecing.bs) {
++        error_setg(errp, "no associated fleecing image");
++        return -1;
++    }
++
++    QDict *cbw_opts = qdict_new();
++    qdict_put_str(cbw_opts, "driver", "copy-before-write");
++    qdict_put_str(cbw_opts, "file", bdrv_get_node_name(di->bs));
++    qdict_put_str(cbw_opts, "target", bdrv_get_node_name(di->fleecing.bs));
++
++    if (di->bitmap) {
++        /*
++         * Only guest writes to parts relevant for the backup need to be intercepted with
++         * old data being copied to the fleecing image.
++         */
++        qdict_put_str(cbw_opts, "bitmap.node", bdrv_get_node_name(di->bs));
++        qdict_put_str(cbw_opts, "bitmap.name", bdrv_dirty_bitmap_name(di->bitmap));
++    }
++    /*
++     * Fleecing storage is supposed to be fast and it's better to break backup than guest
++     * writes. Certain guest drivers like VirtIO-win have 60 seconds timeout by default, so
++     * abort a bit before that.
++     */
++    qdict_put_str(cbw_opts, "on-cbw-error", "break-snapshot");
++    qdict_put_int(cbw_opts, "cbw-timeout", 45);
++
++    di->fleecing.cbw = bdrv_insert_node(di->bs, cbw_opts, BDRV_O_RDWR, &local_err);
++
++    if (!di->fleecing.cbw) {
++        error_setg(errp, "appending cbw node for fleecing failed: %s",
++                   local_err ? error_get_pretty(local_err) : "unknown error");
++        return -1;
++    }
++
++    QDict *snapshot_access_opts = qdict_new();
++    qdict_put_str(snapshot_access_opts, "driver", "snapshot-access");
++    qdict_put_str(snapshot_access_opts, "file", bdrv_get_node_name(di->fleecing.cbw));
++
++    di->fleecing.snapshot_access =
++        bdrv_open(NULL, NULL, snapshot_access_opts, BDRV_O_RDWR | BDRV_O_UNMAP, &local_err);
++    if (!di->fleecing.snapshot_access) {
++        error_setg(errp, "setting up snapshot access for fleecing failed: %s",
++                   local_err ? error_get_pretty(local_err) : "unknown error");
++        return -1;
++    }
++
++    return 0;
++}
++
+ /*
+  * backup_job_create can *not* be run from a coroutine, so this can't either.
+  * The caller is responsible that backup_mutex is held nonetheless.
+@@ -569,49 +625,14 @@ static void create_backup_jobs_bh(void *opaque) {
+         const char *job_id = bdrv_get_device_name(di->bs);
+         bdrv_graph_co_rdunlock();
+         if (di->fleecing.bs) {
+-            QDict *cbw_opts = qdict_new();
+-            qdict_put_str(cbw_opts, "driver", "copy-before-write");
+-            qdict_put_str(cbw_opts, "file", bdrv_get_node_name(di->bs));
+-            qdict_put_str(cbw_opts, "target", bdrv_get_node_name(di->fleecing.bs));
+-
+-            if (di->bitmap) {
+-                /*
+-                 * Only guest writes to parts relevant for the backup need to be intercepted with
+-                 * old data being copied to the fleecing image.
+-                 */
+-                qdict_put_str(cbw_opts, "bitmap.node", bdrv_get_node_name(di->bs));
+-                qdict_put_str(cbw_opts, "bitmap.name", bdrv_dirty_bitmap_name(di->bitmap));
+-            }
+-            /*
+-             * Fleecing storage is supposed to be fast and it's better to break backup than guest
+-             * writes. Certain guest drivers like VirtIO-win have 60 seconds timeout by default, so
+-             * abort a bit before that.
+-             */
+-            qdict_put_str(cbw_opts, "on-cbw-error", "break-snapshot");
+-            qdict_put_int(cbw_opts, "cbw-timeout", 45);
+-
+-            di->fleecing.cbw = bdrv_insert_node(di->bs, cbw_opts, BDRV_O_RDWR, &local_err);
+-
+-            if (!di->fleecing.cbw) {
+-                error_setg(errp, "appending cbw node for fleecing failed: %s",
+-                           local_err ? error_get_pretty(local_err) : "unknown error");
+-                bdrv_drained_end(di->bs);
+-                break;
+-            }
+-
+-            QDict *snapshot_access_opts = qdict_new();
+-            qdict_put_str(snapshot_access_opts, "driver", "snapshot-access");
+-            qdict_put_str(snapshot_access_opts, "file", bdrv_get_node_name(di->fleecing.cbw));
+-
+-            di->fleecing.snapshot_access =
+-                bdrv_open(NULL, NULL, snapshot_access_opts, BDRV_O_RDWR | BDRV_O_UNMAP, &local_err);
+-            if (!di->fleecing.snapshot_access) {
++            if (setup_snapshot_access(di, &local_err) < 0) {
+                 error_setg(errp, "setting up snapshot access for fleecing failed: %s",
+                            local_err ? error_get_pretty(local_err) : "unknown error");
+                 cleanup_snapshot_access(di);
+                 bdrv_drained_end(di->bs);
+                 break;
+             }
++
+             source_bs = di->fleecing.snapshot_access;
+             discard_source = true;
+ 

debian/patches/pve/0050-PVE-backup-save-device-name-in-device-info-structure.patch

@@ -0,0 +1,135 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fiona Ebner <f.ebner@proxmox.com>
+Date: Thu, 7 Nov 2024 17:51:16 +0100
+Subject: [PATCH] PVE backup: save device name in device info structure
+
+The device name needs to be queried while holding the graph read lock
+and since it doesn't change during the whole operation, just get it
+once during setup and avoid the need to query it again in different
+places.
+
+Also in preparation to use it more often in error messages and for the
+upcoming external backup access API.
+
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ pve-backup.c | 29 +++++++++++++++--------------
+ 1 file changed, 15 insertions(+), 14 deletions(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index 051ebffe48..33c23e53c2 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -94,6 +94,7 @@ typedef struct PVEBackupDevInfo {
+     size_t size;
+     uint64_t block_size;
+     uint8_t dev_id;
++    char* device_name;
+     int completed_ret; // INT_MAX if not completed
+     BdrvDirtyBitmap *bitmap;
+     BlockDriverState *target;
+@@ -327,6 +328,8 @@ static void coroutine_fn pvebackup_co_complete_stream(void *opaque)
+     }
+ 
+     di->bs = NULL;
++    g_free(di->device_name);
++    di->device_name = NULL;
+ 
+     assert(di->target == NULL);
+ 
+@@ -621,9 +624,6 @@ static void create_backup_jobs_bh(void *opaque) {
+ 
+         BlockDriverState *source_bs = di->bs;
+         bool discard_source = false;
+-        bdrv_graph_co_rdlock();
+-        const char *job_id = bdrv_get_device_name(di->bs);
+-        bdrv_graph_co_rdunlock();
+         if (di->fleecing.bs) {
+             if (setup_snapshot_access(di, &local_err) < 0) {
+                 error_setg(errp, "setting up snapshot access for fleecing failed: %s",
+@@ -654,7 +654,7 @@ static void create_backup_jobs_bh(void *opaque) {
+         }
+ 
+         BlockJob *job = backup_job_create(
+-            job_id, source_bs, di->target, backup_state.speed, sync_mode, di->bitmap,
++            di->device_name, source_bs, di->target, backup_state.speed, sync_mode, di->bitmap,
+             bitmap_mode, false, discard_source, NULL, &perf, BLOCKDEV_ON_ERROR_REPORT,
+             BLOCKDEV_ON_ERROR_REPORT, JOB_DEFAULT, pvebackup_complete_cb, di, backup_state.txn,
+             &local_err);
+@@ -751,6 +751,7 @@ static GList coroutine_fn GRAPH_RDLOCK *get_device_info(
+             }
+             PVEBackupDevInfo *di = g_new0(PVEBackupDevInfo, 1);
+             di->bs = bs;
++            di->device_name = g_strdup(bdrv_get_device_name(bs));
+ 
+             if (fleecing && device_uses_fleecing(*d)) {
+                 g_autofree gchar *fleecing_devid = g_strconcat(*d, "-fleecing", NULL);
+@@ -789,6 +790,7 @@ static GList coroutine_fn GRAPH_RDLOCK *get_device_info(
+ 
+             PVEBackupDevInfo *di = g_new0(PVEBackupDevInfo, 1);
+             di->bs = bs;
++            di->device_name = g_strdup(bdrv_get_device_name(bs));
+             di_list = g_list_append(di_list, di);
+         }
+     }
+@@ -956,9 +958,6 @@ UuidInfo coroutine_fn *qmp_backup(
+ 
+             di->block_size = dump_cb_block_size;
+ 
+-            bdrv_graph_co_rdlock();
+-            const char *devname = bdrv_get_device_name(di->bs);
+-            bdrv_graph_co_rdunlock();
+             PBSBitmapAction action = PBS_BITMAP_ACTION_NOT_USED;
+             size_t dirty = di->size;
+ 
+@@ -973,7 +972,8 @@ UuidInfo coroutine_fn *qmp_backup(
+                     }
+                     action = PBS_BITMAP_ACTION_NEW;
+                 } else {
+-                    expect_only_dirty = proxmox_backup_check_incremental(pbs, devname, di->size) != 0;
++                    expect_only_dirty =
++                        proxmox_backup_check_incremental(pbs, di->device_name, di->size) != 0;
+                 }
+ 
+                 if (expect_only_dirty) {
+@@ -997,7 +997,8 @@ UuidInfo coroutine_fn *qmp_backup(
+                 }
+             }
+ 
+-            int dev_id = proxmox_backup_co_register_image(pbs, devname, di->size, expect_only_dirty, errp);
++            int dev_id = proxmox_backup_co_register_image(pbs, di->device_name, di->size,
++                                                          expect_only_dirty, errp);
+             if (dev_id < 0) {
+                 goto err_mutex;
+             }
+@@ -1009,7 +1010,7 @@ UuidInfo coroutine_fn *qmp_backup(
+             di->dev_id = dev_id;
+ 
+             PBSBitmapInfo *info = g_malloc(sizeof(*info));
+-            info->drive = g_strdup(devname);
++            info->drive = g_strdup(di->device_name);
+             info->action = action;
+             info->size = di->size;
+             info->dirty = dirty;
+@@ -1034,10 +1035,7 @@ UuidInfo coroutine_fn *qmp_backup(
+                 goto err_mutex;
+             }
+ 
+-            bdrv_graph_co_rdlock();
+-            const char *devname = bdrv_get_device_name(di->bs);
+-            bdrv_graph_co_rdunlock();
+-            di->dev_id = vma_writer_register_stream(vmaw, devname, di->size);
++            di->dev_id = vma_writer_register_stream(vmaw, di->device_name, di->size);
+             if (di->dev_id <= 0) {
+                 error_set(errp, ERROR_CLASS_GENERIC_ERROR,
+                           "register_stream failed");
+@@ -1148,6 +1146,9 @@ err:
+             bdrv_co_unref(di->target);
+         }
+ 
++        g_free(di->device_name);
++        di->device_name = NULL;
++
+         g_free(di);
+     }
+     g_list_free(di_list);

debian/patches/pve/0051-PVE-backup-include-device-name-in-error-when-setting.patch

@@ -0,0 +1,25 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fiona Ebner <f.ebner@proxmox.com>
+Date: Thu, 7 Nov 2024 17:51:17 +0100
+Subject: [PATCH] PVE backup: include device name in error when setting up
+ snapshot access fails
+
+Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
+---
+ pve-backup.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index 33c23e53c2..d931746453 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -626,7 +626,8 @@ static void create_backup_jobs_bh(void *opaque) {
+         bool discard_source = false;
+         if (di->fleecing.bs) {
+             if (setup_snapshot_access(di, &local_err) < 0) {
+-                error_setg(errp, "setting up snapshot access for fleecing failed: %s",
++                error_setg(errp, "%s - setting up snapshot access for fleecing failed: %s",
++                           di->device_name,
+                            local_err ? error_get_pretty(local_err) : "unknown error");
+                 cleanup_snapshot_access(di);
+                 bdrv_drained_end(di->bs);

debian/patches/series

@@ -3,18 +3,38 @@ extra/0002-scsi-megasas-Internal-cdbs-have-16-byte-length.patch
 extra/0003-ide-avoid-potential-deadlock-when-draining-during-tr.patch
 extra/0004-Revert-x86-acpi-workaround-Windows-not-handling-name.patch
 extra/0005-block-copy-before-write-use-uint64_t-for-timeout-in-.patch
-extra/0006-Revert-virtio-pci-fix-use-of-a-released-vector.patch
+extra/0006-block-copy-before-write-fix-permission.patch
-extra/0007-block-copy-before-write-fix-permission.patch
+extra/0007-block-copy-before-write-support-unligned-snapshot-di.patch
-extra/0008-block-copy-before-write-support-unligned-snapshot-di.patch
+extra/0008-block-copy-before-write-create-block_copy-bitmap-in-.patch
-extra/0009-block-copy-before-write-create-block_copy-bitmap-in-.patch
+extra/0009-qapi-blockdev-backup-add-discard-source-parameter.patch
-extra/0010-qapi-blockdev-backup-add-discard-source-parameter.patch
+extra/0010-hw-virtio-Fix-the-de-initialization-of-vhost-user-de.patch
-extra/0011-hw-virtio-Fix-the-de-initialization-of-vhost-user-de.patch
+extra/0011-target-arm-Use-float_status-copy-in-sme_fmopa_s.patch
-extra/0012-target-arm-Use-float_status-copy-in-sme_fmopa_s.patch
+extra/0012-target-arm-Use-FPST_F16-for-SME-FMOPA-widening.patch
-extra/0013-target-arm-Use-FPST_F16-for-SME-FMOPA-widening.patch
+extra/0013-scsi-fix-regression-and-honor-bootindex-again-for-le.patch
-extra/0014-scsi-fix-regression-and-honor-bootindex-again-for-le.patch
+extra/0014-hw-scsi-lsi53c895a-bump-instruction-limit-in-scripts.patch
-extra/0015-hw-scsi-lsi53c895a-bump-instruction-limit-in-scripts.patch
+extra/0015-block-copy-Fix-missing-graph-lock.patch
-extra/0016-block-copy-Fix-missing-graph-lock.patch
+extra/0016-Revert-qemu-char-do-not-operate-on-sources-from-fina.patch
-extra/0017-Revert-qemu-char-do-not-operate-on-sources-from-fina.patch
+extra/0017-virtio-pci-Fix-the-use-of-an-uninitialized-irqfd.patch
+extra/0018-virtio-net-Ensure-queue-index-fits-with-RSS.patch
+extra/0019-virtio-net-Fix-network-stall-at-the-host-side-waitin.patch
+extra/0020-net-Reinstate-net-nic-model-help-output-as-documente.patch
+extra/0021-net-Fix-net-nic-model-for-non-help-arguments.patch
+extra/0022-target-arm-Don-t-assert-for-128-bit-tile-accesses-wh.patch
+extra/0023-target-arm-Fix-UMOPA-UMOPS-of-16-bit-values.patch
+extra/0024-target-arm-Avoid-shifts-by-1-in-tszimm_shr-and-tszim.patch
+extra/0025-target-arm-Ignore-SMCR_EL2.LEN-and-SVCR_EL2.LEN-if-E.patch
+extra/0026-target-arm-Handle-denormals-correctly-for-FMOPA-wide.patch
+extra/0027-intel_iommu-fix-FRCD-construction-macro.patch
+extra/0028-target-i386-Do-not-apply-REX-to-MMX-operands.patch
+extra/0029-module-Prevent-crash-by-resetting-local_err-in-modul.patch
+extra/0030-nbd-server-Plumb-in-new-args-to-nbd_client_add.patch
+extra/0031-nbd-server-CVE-2024-7409-Cap-default-max-connections.patch
+extra/0032-nbd-server-CVE-2024-7409-Drop-non-negotiating-client.patch
+extra/0033-nbd-server-CVE-2024-7409-Close-stray-clients-at-serv.patch
+extra/0034-vnc-fix-crash-when-no-console-attached.patch
+extra/0035-nbd-server-CVE-2024-7409-Avoid-use-after-free-when-c.patch
+extra/0036-softmmu-physmem-fix-memory-leak-in-dirty_memory_exte.patch
+extra/0037-block-reqlist-allow-adding-overlapping-requests.patch
 bitmap-mirror/0001-drive-mirror-add-support-for-sync-bitmap-mode-never.patch
 bitmap-mirror/0002-drive-mirror-add-support-for-conditional-and-always-.patch
 bitmap-mirror/0003-mirror-add-check-for-bitmap-mode-without-bitmap.patch
@@ -68,3 +88,7 @@ pve/0044-copy-before-write-allow-specifying-minimum-cluster-s.patch
 pve/0045-backup-add-minimum-cluster-size-to-performance-optio.patch
 pve/0046-PVE-backup-add-fleecing-option.patch
 pve/0047-PVE-backup-improve-error-when-copy-before-write-fail.patch
+pve/0048-PVE-backup-fixup-error-handling-for-fleecing.patch
+pve/0049-PVE-backup-factor-out-setting-up-snapshot-access-for.patch
+pve/0050-PVE-backup-save-device-name-in-device-info-structure.patch
+pve/0051-PVE-backup-include-device-name-in-error-when-setting.patch

qemu

@@ -1 +1 @@
-Subproject commit c25df57ae8f9fe1c72eee2dab37d76d904ac382e
+Subproject commit 5ebde3b5c00e15f560f73055fac4ab31c0cac6d2