2020-05-04 15:35:01 +03:00
|
|
|
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
|
|
|
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
|
|
|
|
|
Date: Mon, 4 May 2020 11:05:08 +0200
|
2021-02-11 19:11:11 +03:00
|
|
|
Subject: [PATCH] PVE: add optional buffer size to QEMUFile
|
2020-05-04 15:35:01 +03:00
|
|
|
|
|
|
|
|
So we can use a 4M buffer for savevm-async which should
|
|
|
|
|
increase performance storing the state onto ceph.
|
|
|
|
|
|
|
|
|
|
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
|
2021-02-11 19:11:11 +03:00
|
|
|
[increase max IOV count in QEMUFile to actually write more data]
|
|
|
|
|
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
|
2022-01-13 12:34:33 +03:00
|
|
|
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
[FE: adapt to removal of QEMUFileOps]
|
|
|
|
|
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
|
2020-05-04 15:35:01 +03:00
|
|
|
---
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
migration/qemu-file.c | 50 +++++++++++++++++++++++++++-------------
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
migration/qemu-file.h | 2 ++
|
|
|
|
|
migration/savevm-async.c | 5 ++--
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
3 files changed, 39 insertions(+), 18 deletions(-)
|
2020-05-04 15:35:01 +03:00
|
|
|
|
|
|
|
|
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
|
2024-04-25 18:21:29 +03:00
|
|
|
index a10882d47f..19c1de0472 100644
|
2020-05-04 15:35:01 +03:00
|
|
|
--- a/migration/qemu-file.c
|
|
|
|
|
+++ b/migration/qemu-file.c
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -35,8 +35,8 @@
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
#include "rdma.h"
|
2024-04-25 18:21:29 +03:00
|
|
|
#include "io/channel-file.h"
|
2020-05-04 15:35:01 +03:00
|
|
|
|
|
|
|
|
-#define IO_BUF_SIZE 32768
|
2021-02-11 19:11:11 +03:00
|
|
|
-#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 64)
|
2020-05-04 15:35:01 +03:00
|
|
|
+#define DEFAULT_IO_BUF_SIZE 32768
|
2021-02-11 19:11:11 +03:00
|
|
|
+#define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 256)
|
2020-05-04 15:35:01 +03:00
|
|
|
|
|
|
|
|
struct QEMUFile {
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
QIOChannel *ioc;
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -44,7 +44,8 @@ struct QEMUFile {
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
|
2020-05-04 15:35:01 +03:00
|
|
|
int buf_index;
|
|
|
|
|
int buf_size; /* 0 when writing */
|
|
|
|
|
- uint8_t buf[IO_BUF_SIZE];
|
|
|
|
|
+ size_t buf_allocated_size;
|
|
|
|
|
+ uint8_t *buf;
|
|
|
|
|
|
|
|
|
|
DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
|
|
|
|
|
struct iovec iov[MAX_IOV_SIZE];
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -101,7 +102,9 @@ int qemu_file_shutdown(QEMUFile *f)
|
2023-10-17 15:10:09 +03:00
|
|
|
return 0;
|
2020-05-04 15:35:01 +03:00
|
|
|
}
|
|
|
|
|
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
-static QEMUFile *qemu_file_new_impl(QIOChannel *ioc, bool is_writable)
|
|
|
|
|
+static QEMUFile *qemu_file_new_impl(QIOChannel *ioc,
|
|
|
|
|
+ bool is_writable,
|
|
|
|
|
+ size_t buffer_size)
|
2020-05-04 15:35:01 +03:00
|
|
|
{
|
|
|
|
|
QEMUFile *f;
|
|
|
|
|
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -110,6 +113,8 @@ static QEMUFile *qemu_file_new_impl(QIOChannel *ioc, bool is_writable)
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
object_ref(ioc);
|
|
|
|
|
f->ioc = ioc;
|
|
|
|
|
f->is_writable = is_writable;
|
2020-05-04 15:35:01 +03:00
|
|
|
+ f->buf_allocated_size = buffer_size;
|
|
|
|
|
+ f->buf = malloc(buffer_size);
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
|
2020-05-04 15:35:01 +03:00
|
|
|
return f;
|
|
|
|
|
}
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -120,17 +125,27 @@ static QEMUFile *qemu_file_new_impl(QIOChannel *ioc, bool is_writable)
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
*/
|
|
|
|
|
QEMUFile *qemu_file_get_return_path(QEMUFile *f)
|
|
|
|
|
{
|
|
|
|
|
- return qemu_file_new_impl(f->ioc, !f->is_writable);
|
|
|
|
|
+ return qemu_file_new_impl(f->ioc, !f->is_writable, DEFAULT_IO_BUF_SIZE);
|
|
|
|
|
}
|
2020-05-04 15:35:01 +03:00
|
|
|
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
QEMUFile *qemu_file_new_output(QIOChannel *ioc)
|
|
|
|
|
{
|
|
|
|
|
- return qemu_file_new_impl(ioc, true);
|
|
|
|
|
+ return qemu_file_new_impl(ioc, true, DEFAULT_IO_BUF_SIZE);
|
|
|
|
|
+}
|
|
|
|
|
+
|
|
|
|
|
+QEMUFile *qemu_file_new_output_sized(QIOChannel *ioc, size_t buffer_size)
|
2020-05-04 15:35:01 +03:00
|
|
|
+{
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
+ return qemu_file_new_impl(ioc, true, buffer_size);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
QEMUFile *qemu_file_new_input(QIOChannel *ioc)
|
|
|
|
|
{
|
|
|
|
|
- return qemu_file_new_impl(ioc, false);
|
|
|
|
|
+ return qemu_file_new_impl(ioc, false, DEFAULT_IO_BUF_SIZE);
|
2020-05-04 15:35:01 +03:00
|
|
|
+}
|
|
|
|
|
+
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
+QEMUFile *qemu_file_new_input_sized(QIOChannel *ioc, size_t buffer_size)
|
|
|
|
|
+{
|
|
|
|
|
+ return qemu_file_new_impl(ioc, false, buffer_size);
|
|
|
|
|
}
|
2020-05-04 15:35:01 +03:00
|
|
|
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
/*
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -328,7 +343,7 @@ static ssize_t coroutine_mixed_fn qemu_fill_buffer(QEMUFile *f)
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
do {
|
|
|
|
|
len = qio_channel_read(f->ioc,
|
|
|
|
|
(char *)f->buf + pending,
|
|
|
|
|
- IO_BUF_SIZE - pending,
|
|
|
|
|
+ f->buf_allocated_size - pending,
|
|
|
|
|
&local_error);
|
|
|
|
|
if (len == QIO_CHANNEL_ERR_BLOCK) {
|
|
|
|
|
if (qemu_in_coroutine()) {
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -368,6 +383,9 @@ int qemu_fclose(QEMUFile *f)
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
ret = ret2;
|
2020-05-04 15:35:01 +03:00
|
|
|
}
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
g_clear_pointer(&f->ioc, object_unref);
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
+
|
2020-05-04 15:35:01 +03:00
|
|
|
+ free(f->buf);
|
|
|
|
|
+
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
error_free(f->last_error_obj);
|
|
|
|
|
g_free(f);
|
|
|
|
|
trace_qemu_file_fclose();
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -416,7 +434,7 @@ static void add_buf_to_iovec(QEMUFile *f, size_t len)
|
2020-05-04 15:35:01 +03:00
|
|
|
{
|
|
|
|
|
if (!add_to_iovec(f, f->buf + f->buf_index, len, false)) {
|
|
|
|
|
f->buf_index += len;
|
|
|
|
|
- if (f->buf_index == IO_BUF_SIZE) {
|
|
|
|
|
+ if (f->buf_index == f->buf_allocated_size) {
|
|
|
|
|
qemu_fflush(f);
|
|
|
|
|
}
|
|
|
|
|
}
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -441,7 +459,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
|
2020-05-04 15:35:01 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
while (size > 0) {
|
|
|
|
|
- l = IO_BUF_SIZE - f->buf_index;
|
|
|
|
|
+ l = f->buf_allocated_size - f->buf_index;
|
|
|
|
|
if (l > size) {
|
|
|
|
|
l = size;
|
|
|
|
|
}
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -587,8 +605,8 @@ size_t coroutine_mixed_fn qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t si
|
2020-05-04 15:35:01 +03:00
|
|
|
size_t index;
|
|
|
|
|
|
|
|
|
|
assert(!qemu_file_is_writable(f));
|
|
|
|
|
- assert(offset < IO_BUF_SIZE);
|
|
|
|
|
- assert(size <= IO_BUF_SIZE - offset);
|
|
|
|
|
+ assert(offset < f->buf_allocated_size);
|
|
|
|
|
+ assert(size <= f->buf_allocated_size - offset);
|
|
|
|
|
|
|
|
|
|
/* The 1st byte to read from */
|
|
|
|
|
index = f->buf_index + offset;
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -638,7 +656,7 @@ size_t coroutine_mixed_fn qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size
|
2020-05-04 15:35:01 +03:00
|
|
|
size_t res;
|
|
|
|
|
uint8_t *src;
|
|
|
|
|
|
|
|
|
|
- res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0);
|
|
|
|
|
+ res = qemu_peek_buffer(f, &src, MIN(pending, f->buf_allocated_size), 0);
|
|
|
|
|
if (res == 0) {
|
|
|
|
|
return done;
|
|
|
|
|
}
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -672,7 +690,7 @@ size_t coroutine_mixed_fn qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size
|
2020-05-04 15:35:01 +03:00
|
|
|
*/
|
2023-10-17 15:10:09 +03:00
|
|
|
size_t coroutine_mixed_fn qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
|
2020-05-04 15:35:01 +03:00
|
|
|
{
|
|
|
|
|
- if (size < IO_BUF_SIZE) {
|
|
|
|
|
+ if (size < f->buf_allocated_size) {
|
|
|
|
|
size_t res;
|
2021-05-27 13:43:32 +03:00
|
|
|
uint8_t *src = NULL;
|
2020-05-04 15:35:01 +03:00
|
|
|
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -697,7 +715,7 @@ int coroutine_mixed_fn qemu_peek_byte(QEMUFile *f, int offset)
|
2020-05-04 15:35:01 +03:00
|
|
|
int index = f->buf_index + offset;
|
|
|
|
|
|
|
|
|
|
assert(!qemu_file_is_writable(f));
|
|
|
|
|
- assert(offset < IO_BUF_SIZE);
|
|
|
|
|
+ assert(offset < f->buf_allocated_size);
|
|
|
|
|
|
|
|
|
|
if (index >= f->buf_size) {
|
|
|
|
|
qemu_fill_buffer(f);
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -811,7 +829,7 @@ static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
|
2020-05-04 15:35:01 +03:00
|
|
|
ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
|
|
|
|
|
const uint8_t *p, size_t size)
|
|
|
|
|
{
|
|
|
|
|
- ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
|
|
|
|
|
+ ssize_t blen = f->buf_allocated_size - f->buf_index - sizeof(int32_t);
|
|
|
|
|
|
|
|
|
|
if (blen < compressBound(size)) {
|
|
|
|
|
return -1;
|
|
|
|
|
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
|
2024-04-25 18:21:29 +03:00
|
|
|
index 32fd4a34fd..36a0cd8cc8 100644
|
2020-05-04 15:35:01 +03:00
|
|
|
--- a/migration/qemu-file.h
|
|
|
|
|
+++ b/migration/qemu-file.h
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
@@ -30,7 +30,9 @@
|
|
|
|
|
#include "io/channel.h"
|
2020-05-04 15:35:01 +03:00
|
|
|
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
QEMUFile *qemu_file_new_input(QIOChannel *ioc);
|
|
|
|
|
+QEMUFile *qemu_file_new_input_sized(QIOChannel *ioc, size_t buffer_size);
|
|
|
|
|
QEMUFile *qemu_file_new_output(QIOChannel *ioc);
|
|
|
|
|
+QEMUFile *qemu_file_new_output_sized(QIOChannel *ioc, size_t buffer_size);
|
2020-05-04 15:35:01 +03:00
|
|
|
int qemu_fclose(QEMUFile *f);
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
|
update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.
During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.
The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.
Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.
Major changes only affect alloc-track:
* It is not possible to call a generated co-wrapper like
bdrv_get_info() while holding the block graph lock exclusively [0],
which does happen during initialization of alloc-track when the
backing hd is set and the refresh_limits driver callback is invoked.
The bdrv_get_info() call to get the cluster size is moved to
directly after opening the file child in track_open().
The important thing is that at least the request alignment for the
write target is used, because then the RMW cycle in bdrv_pwritev
will gather enough data from the backing file. Partial cluster
allocations in the target are not a fundamental issue, because the
driver returns its allocation status based on the bitmap, so any
other data that maps to the same cluster will still be copied later
by a stream job (or during writes to that cluster).
* Replacing the node cannot be done in the
track_co_change_backing_file() callback, because it is a coroutine
and cannot hold the block graph lock exclusively. So it is moved to
the stream job itself with the auto-remove option not having an
effect anymore (qemu-server would always set it anyways).
In the future, there could either be a special option for the stream
job, or maybe the upcoming blockdev-replace QMP command can be used.
Replacing the backing child is actually already done in the stream
job, so no need to do it in the track_co_change_backing_file()
callback. It also cannot be called from a coroutine. Looking at the
implementation in the qcow2 driver, it doesn't seem to be intended
to change the backing child itself, just update driver-internal
state.
Other changes:
* alloc-track: Error out early when used without auto-remove. Since
replacing the node now happens in the stream job, where the option
cannot be read from (it's internal to the driver), it will always be
treated as 'on'. Makes sure to have users beside qemu-server notice
the change (should they even exist). The option can be fully dropped
in the future while adding a version guard in qemu-server.
* alloc-track: Avoid seemingly superfluous child permission update.
Doesn't seem necessary nowadays (maybe after commit "alloc-track:
fix deadlock during drop" where the dropping is not rescheduled and
delayed anymore or some upstream change). Replacing the block node
will already update the permissions of the new node (which was the
file child before). Should there really be some issue, instead of
having a drop state, this could also be just based off the fact
whether there is still a backing child.
Dumping the cumulative (shared) permissions for the BDS with a debug
print yields the same values after this patch and with QEMU 8.1,
namely 3 and 5.
* PBS block driver: compile unconditionally. Proxmox VE always needs
it and something in the build process changed to make it not enabled
by default. Probably would need to move the build option to meson
otherwise.
* backup: job unreferencing during cleanup needs to happen outside of
coroutine, so it was moved to before invoking the clean
* mirror: Cherry-pick stable fix to avoid potential deadlock.
* savevm-async: migrate_init now can fail, so propagate potential
error.
* savevm-async: compression counters are not accessible outside
migration/ram-compress now, so drop code that prophylactically set
it to zero.
[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-25 18:21:28 +03:00
|
|
|
/*
|
2021-02-11 19:11:11 +03:00
|
|
|
diff --git a/migration/savevm-async.c b/migration/savevm-async.c
|
2024-04-25 18:21:29 +03:00
|
|
|
index 779e4e2a78..bf36fc06d2 100644
|
2021-02-11 19:11:11 +03:00
|
|
|
--- a/migration/savevm-async.c
|
|
|
|
|
+++ b/migration/savevm-async.c
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -379,7 +379,7 @@ void qmp_savevm_start(const char *statefile, Error **errp)
|
2020-05-04 15:35:01 +03:00
|
|
|
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(snap_state.target,
|
|
|
|
|
&snap_state.bs_pos));
|
|
|
|
|
- snap_state.file = qemu_file_new_output(ioc);
|
|
|
|
|
+ snap_state.file = qemu_file_new_output_sized(ioc, 4 * 1024 * 1024);
|
2020-05-04 15:35:01 +03:00
|
|
|
|
|
|
|
|
if (!snap_state.file) {
|
|
|
|
|
error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
|
2024-04-25 18:21:29 +03:00
|
|
|
@@ -496,7 +496,8 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
|
2020-05-04 15:35:01 +03:00
|
|
|
blk_op_block_all(be, blocker);
|
|
|
|
|
|
|
|
|
|
/* restore the VM state */
|
update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 15:07:13 +03:00
|
|
|
- f = qemu_file_new_input(QIO_CHANNEL(qio_channel_savevm_async_new(be, &bs_pos)));
|
|
|
|
|
+ f = qemu_file_new_input_sized(QIO_CHANNEL(qio_channel_savevm_async_new(be, &bs_pos)),
|
|
|
|
|
+ 4 * 1024 * 1024);
|
2020-05-04 15:35:01 +03:00
|
|
|
if (!f) {
|
|
|
|
|
error_setg(errp, "Could not open VM state file");
|
|
|
|
|
goto the_end;
|