Commit Graph

63 Commits (8275e2f6be8b10c2b3da0fe6927d0ce7ad438c80)

Author SHA1 Message Date
Stefan Hajnoczi 297a75e6c5 virtio: add virtqueue_rewind()
virtqueue_discard() requires a VirtQueueElement but virtio-balloon does
not migrate its in-use element.  Introduce a new function that is
similar to virtqueue_discard() but doesn't require a VirtQueueElement.

This will allow virtio-balloon to access element again after migration
with the usual proviso that the guest may have modified the vring since
last time.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-09 20:58:34 +03:00
Dr. David Alan Gilbert 5943124cc0 virtio: Migration helper function and macro
To make conversion of virtio devices to VMState simple
at first add a helper function for the simple virtio_save
case and a helper macro that defines the VMState structure.
These will probably go away or change as more of the virtio
code gets converted.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-21 20:44:19 +03:00
Fam Zheng 872dd82c83 virtio: Introduce virtio_add_queue_aio
Using this function instead of virtio_add_queue marks the vq as aio
based. This differentiation will be useful in later patches.

Distinguish between virtqueue processing in the iohandler context and main loop
AioContext.  iohandler context is isolated from AioContexts and therefore does
not run during aio_poll().

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-21 20:44:19 +03:00
Fam Zheng bf1780b0d5 virtio: Add typedef for handle_output
The function pointer signature has been repeated a few times, using a
typedef may make coding easier.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-21 20:44:19 +03:00
Markus Armbruster 2a6a4076e1 Clean up ill-advised or unusual header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Stefan Hajnoczi 3a90c4ace2 virtio: drop duplicate virtio_queue_get_id() function
The virtio_queue_get_id() function is the lesser used duplicate of
virtio_get_queue_index().  Use the latter instead.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1463767461-17922-1-git-send-email-stefanha@redhat.com
2016-06-07 14:40:51 +01:00
Paolo Bonzini a378b49a43 virtio: merge virtio_queue_aio_set_host_notifier_handler with virtio_queue_set_aio
Eliminating the reentrancy is actually a nice thing that we can do
with the API that Michael proposed, so let's make it first class.
This also hides the complex assign/set_handler conventions from
callers of virtio_queue_aio_set_host_notifier_handler, which in
fact was always called with assign=true.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-04-07 19:57:33 +03:00
Michael S. Tsirkin 344dc16fae virtio: add aio handler
In addition to handling IO in vcpu thread and in io thread, blk dataplane
introduces yet another mode: handling it by AioContext.

Currently, this reuses the same handler as previous modes,
which triggers races as these were not designed to be reentrant.
Add instead a separate handler just for aio; this will make
it possible to disable regular handlers when dataplane is active.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-04-07 19:57:33 +03:00
Paolo Bonzini 2b2cbcadc1 virtio: make virtio_queue_notify_vq static
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-04-07 19:57:33 +03:00
Paolo Bonzini adb3feda8d virtio: export vring_notify as virtio_should_notify
Virtio dataplane needs to trigger the irq manually through the
guest notifier.  Export virtio_should_notify so that it can be
used around event_notifier_set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-25 13:14:18 +02:00
Paolo Bonzini a1afb6062e virtio: add AioContext-specific function for host notifiers
This is used to register ioeventfd with a dataplane thread.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-25 13:14:18 +02:00
Victor Kaplansky 5669655aaf vhost-user interrupt management fixes
Since guest_mask_notifier can not be used in vhost-user mode due
to buffering implied by unix control socket, force
use_mask_notifier on virtio devices of vhost-user interfaces, and
send correct callfd to the guest at vhost start.

Using guest_notifier_mask function in vhost-user case may
break interrupt mask paradigm, because mask/unmask is not
really done when returning from guest_notifier_mask call, instead
message is posted in a unix socket, and processed later.

Add an option boolean flag 'use_mask_notifier' to disable the use
of guest_notifier_mask in virtio pci.

Signed-off-by: Didier Pallard <didier.pallard@6wind.com>
Signed-off-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-18 16:13:56 +02:00
Paolo Bonzini 3724650db0 virtio: introduce virtqueue_alloc_element
Allocate the arrays for in_addr/out_addr/in_sg/out_sg outside the
VirtQueueElement.  For now, virtqueue_pop and vring_pop keep
allocating a very large VirtQueueElement.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06 20:44:08 +02:00
Paolo Bonzini ab281c1781 virtio: introduce qemu_get/put_virtqueue_element
Move allocation to virtio functions also when loading/saving a
VirtQueueElement.  This will also let the load/save functions
keep backwards compatibility when the VirtQueueElement layout
is changed.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06 20:44:08 +02:00
Paolo Bonzini 51b19ebe43 virtio: move allocation to virtqueue_pop/vring_pop
The return code of virtqueue_pop/vring_pop is unused except to check for
errors or 0.  We can thus easily move allocation inside the functions
and just return a pointer to the VirtQueueElement.

The advantage is that we will be able to allocate only the space that
is needed for the actual size of the s/g list instead of the full
VIRTQUEUE_MAX_SIZE items.  Currently VirtQueueElement takes about 48K
of memory, and this kind of allocation puts a lot of stress on malloc.
By cutting the size by two or three orders of magnitude, malloc can
use much more efficient algorithms.

The patch is pretty large, but changes to each device are testable
more or less independently.  Splitting it would mostly add churn.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-02-06 20:39:07 +02:00
Michael S. Tsirkin 3945ecf1ec virtio: drop virtqueue_map_sg
Deprecated in favor of virtqueue_map.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
2015-10-29 11:05:24 +02:00
Michael S. Tsirkin 8059feee00 virtio: introduce virtio_map
virtio_map_sg currently fails if one of the entries it's mapping is
contigious in GPA but not HVA address space.  Introduce virtio_map which
handles this by splitting sg entries.

This new API generally turns out to be a good idea since it's harder to
misuse: at least in one case the existing one was used incorrectly.

This will still fail if there's no space left in the sg, but luckily max
queue size in use is currently 256, while max sg size is 1024, so we
should be OK even is all entries happen to cross a single DIMM boundary.

Won't work well with very small DIMM sizes, unfortunately:
e.g. this will fail with 4K DIMMs where a single
request might span a large number of DIMMs.

Let's hope these are uncommon - at least we are not breaking things.

Note: virtio-scsi calls virtio_map_sg on data loaded from network, and
validates input, asserting on failure.  Copy the validating code here -
it will be dropped from virtio-scsi in a follow-up patch.

Reported-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
2015-10-29 11:05:24 +02:00
Jason Wang 29b9f5efd7 virtio: introduce virtqueue_discard()
This patch introduces virtqueue_discard() to discard a descriptor and
unmap the sgs. This will be used by the patch that will discard
descriptor when packet is truncated.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-01 16:16:52 +03:00
Cornelia Huck 95129d6fc9 virtio: avoid leading underscores for helpers
Commit ef546f1275 ("virtio: add
feature checking helpers") introduced a helper __virtio_has_feature.
We don't want to use reserved identifiers, though, so let's
rename __virtio_has_feature to virtio_has_feature and virtio_has_feature
to virtio_vdev_has_feature.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-10 11:06:05 +03:00
Jason Wang 74aae7b22b virtio: fix 1.0 virtqueue migration
1.0 does not requires physically-contiguous pages layout for a
virtqueue. So we could not infer avail and used from desc. This means
we need to migrate vring.avail and vring.used when host support virtio
1.0. This fixes malfunction of virtio 1.0 device after migration.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-08-05 16:56:34 +03:00
Jason Wang 9d5b731dd2 virtio: get_features() can fail
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-27 18:11:53 +03:00
Michael S. Tsirkin 09999a5f7f virtio: set any_layout in virtio core
Exceptions:
    - virtio-blk
    - compat machine types

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-27 11:24:48 +03:00
Michael S. Tsirkin 5f456073aa virtio: hide legacy features from modern guests
NOTIFY_ON_EMPTY, ANY_LAYOUT and BAD are only valid on the legacy
interface.

Hide them from modern guests.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-27 09:08:50 +03:00
Michael S. Tsirkin adfb743c90 virtio: add modern config accessors
virtio 1.0 defines config space as LE,
as opposed to pre-1.0 which was native endian.

Add API for transports to execute word/dword accesses in
little endian format - will be useful for mmio
and pci (byte access is also wrapped, for completeness).

For simplicity, we still keep config in host native
endian format, byteswap to LE on guest access.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:05 +02:00
Michael S. Tsirkin b8f059081d virtio: generation counter support
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:05 +02:00
Cornelia Huck 0b352fd680 virtio: allow to fail setting status
virtio-1 allow setting of the FEATURES_OK status bit to fail if
the negotiated feature bits are inconsistent: let's fail
virtio_set_status() in that case and update virtio-ccw to post an
error to the guest.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:04 +02:00
Cornelia Huck ab223c9518 virtio: allow virtio-1 queue layout
For virtio-1 devices, we allow a more complex queue layout that doesn't
require descriptor table and rings on a physically-contigous memory area:
add virtio_queue_set_rings() to allow transports to set this up.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:04 +02:00
Cornelia Huck 3c185597c8 virtio: endianness checks for virtio 1.0 devices
Add code that checks for the VERSION_1 feature bit in order to make
decisions about the device's endianness. This allows us to support
transitional devices.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10 18:15:04 +02:00
Gerd Hoffmann d5aaa1b045 virtio: 64bit features fixups.
Commit "019a3ed virtio: make features 64bit wide" missed a few changes,
as I've noticed while trying to rebase the virtio-1 branch to latest
master.  This patch adds them.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-03 18:19:16 +02:00
Gerd Hoffmann 019a3edbb2 virtio: make features 64bit wide
Make features 64bit wide everywhere.

On migration a full 64bit guest_features field is sent if one of the
high bits is set, in addition to the lower 32bit guest_features field
which must stay for compatibility reasons.  That way we send the lower
32 feature bits twice, but the code is simpler because we don't have
to split and compose the 64bit features into two 32bit fields.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-01 14:18:55 +02:00
Jason Wang b829c2a98f virtio: increase the queue limit to 1024
Increase the queue limit to 1024. But virtio-ccw and s390-virtio won't
support this, this is done through failing device_plugged() for those
two transports if the number of virtqueues is greater than 64.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-31 16:50:10 +02:00
Jason Wang 87b3bd1c85 virtio: rename VIRTIO_PCI_QUEUE_MAX to VIRTIO_QUEUE_MAX
VIRTIO_PCI_QUEUE_MAX is not only used for pci, so rename it be generic.

Cc: Amit Shah <amit.shah@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-31 16:50:10 +02:00
Jason Wang 8ad176aaed virtio: introduce virtio_get_num_queues()
This patch introduces virtio_get_num_queues() which iterates the vqs
array and return the number of virtqueues used by device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-31 16:45:38 +02:00
Cornelia Huck cf34f533a1 virtio: move VIRTIO_F_NOTIFY_ON_EMPTY into core
Nearly all transports have been offering VIRTIO_F_NOTIFY_ON_EMPTY,
s390-virtio being the exception. There's no reason why it shouldn't
offer it as well, though (handling is done in core anyway), so let's
move it to the common virtio features.

While we're changing it anyway, fix the indentation for the
DEFINE_VIRTIO_COMMON_FEATURES macro.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-31 16:27:25 +02:00
Cornelia Huck 6b8f102054 virtio: move host_features
Move host_features from the individual transport proxies into
the virtio device. Transports may continue to add feature bits
during device plugging.

This should it make easier to offer different sets of host features
for virtio-1/transitional support.

Tested-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-05-31 16:27:18 +02:00
Gerd Hoffmann f73ddbad39 virtio-input: core code & base class [device]
This patch adds virtio-input support to qemu.  It brings a abstract
base class providing core support, other classes can build on it to
actually implement input devices.

virtio-input basically sends linux input layer events (evdev) over
virtio.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-05-29 10:30:26 +02:00
Michael S. Tsirkin 850d00700b virtio: coding style tweak
no space needed after *.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-04-27 21:02:42 +02:00
Jason Wang e0d686bf4b virtio: introduce vector to virtqueues mapping
Currently we will try to traverse all virtqueues to find a subset that
using a specific vector. This is sub optimal when we will support
hundreds or even thousands of virtqueues. So this patch introduces a
method which could be used by transport to get all virtqueues that
using a same vector. This is done through QLISTs and the number of
QLISTs was queried through a transport specific method. When guest
setting vectors, the virtqueue will be linked and helpers for traverse
the list was also introduced.

The first user will be virtio pci which will use this to speed up
MSI-X masking and unmasking handling.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-04-27 21:02:41 +02:00
Cornelia Huck ef546f1275 virtio: add feature checking helpers
Add a helper function for checking whether a bit is set in the guest
features for a vdev as well as one that works on a feature bit set.

Convert code that open-coded this: It cleans up the code and makes it
easier to extend the guest feature bits.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-02-26 13:04:07 +01:00
Cornelia Huck 0cd09c3a6c virtio: feature bit manipulation helpers
Add virtio_{add,clear}_feature helper functions for manipulating a
feature bits variable. This has some benefits over open coding:
- add check that the bit is in a sane range
- make it obvious at a glance what is going on
- have a central point to change when we want to extend feature bits

Convert existing code manipulating features to use the new helpers.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-02-26 13:04:07 +01:00
Michael S. Tsirkin e9600c6ca9 virtio: use standard-headers
Drop a bunch of code duplicated from virtio_config.h and virtio_ring.h.
This makes us rename event index accessors which conflict,
as reusing the ones from virtio_ring.h isn't trivial.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2015-02-26 13:04:03 +01:00
Gonglei 7766aa0c0e virtio: remove useless declaration of virtio_net_init()
commit 1773d9ee (virtio-net: cleanup: init and exit function)
removed the definition of virtio_net_init(), but didn't remove its
declaration in the header.  Clean that up.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-12-10 11:52:21 +03:00
Gonglei c8075caf19 virtio: add a wrapper for virtio-backend initialization
For better code sharing, add a helper function that handles
reference counting of the virtio backend for virtio proxy devices.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-30 11:09:59 +02:00
Greg Kurz 616a655219 virtio: add endian-ambivalent support to VirtIODevice
Some CPU families can dynamically change their endianness. This means we
can have little endian ppc or big endian arm guests for example. This has
an impact on legacy virtio data structures since they are target endian.
We hence introduce a new property to track the endianness of each virtio
device. It is reasonnably assumed that endianness won't change while the
device is in use : we hence capture the device endianness when it gets
reset.

We migrate this property in a subsection, after the device descriptor. This
means the load code must not rely on it until it is restored. As a consequence,
the vring sanity checks had to be moved after the call to vmstate_load_state().
We enforce paranoia by poisoning the property at the begining of virtio_load().

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-29 19:39:42 +03:00
Greg Kurz 98ed8ecfc9 exec: introduce target_words_bigendian() helper
We currently have a virtio_is_big_endian() helper that provides the target
endianness to the virtio code. As of today, the helper returns a fixed
compile-time value. Of course, this will have to change if we want to
support target endianness changes at run-time.

Let's move the TARGET_WORDS_BIGENDIAN bits out to a new helper and have
virtio_is_big_endian() implemented on top of it.

This patch doesn't change any functionality.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-29 19:39:42 +03:00
Greg Kurz 1b5fc0dea4 virtio: introduce device specific migration calls
In order to migrate virtio subsections, they should be streamed after
the device itself. We need the device specific code to be called from
the common migration code to achieve this. This patch introduces load
and save methods for this purpose.

Suggested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-29 19:39:41 +03:00
Andreas Färber 306ec6c3ce virtio: Convert exit to unrealize
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-09 21:46:49 +01:00
Andreas Färber 0ba94b6f94 virtio: Complete converting VirtioDevice to QOM realize
Drop VirtioDeviceClass::init.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-09 21:46:49 +01:00
Andreas Färber 1d244b42d2 virtio: Start converting VirtioDevice to QOM realize
Temporarily allow either VirtioDeviceClass::init or
VirtioDeviceClass::realize.

Introduce VirtioDeviceClass::unrealize for symmetry.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-09 21:46:49 +01:00
Paolo Bonzini 5e96f5d2f8 virtio-bus: cleanup plug/unplug interface
Right now we have these pairs:

- virtio_bus_plug_device/virtio_bus_destroy_device.  The first
  takes a VirtIODevice, the second takes a VirtioBusState

- device_plugged/device_unplug callbacks in the VirtioBusClass
  (here it's just the naming that is inconsistent)

- virtio_bus_destroy_device is not called by anyone (and since
  it calls qdev_free, it would be called by the proxies---but
  then the callback is useless since the proxies can do whatever
  they want before calling virtio_bus_destroy_device)

And there is a k->init but no k->exit, hence virtio_device_exit is
overwritten by subclasses (except virtio-9p).  This cleans it up by:

- renaming the device_unplug callback to device_unplugged

- renaming virtio_bus_plug_device to virtio_bus_device_plugged,
  matching the callback name

- renaming virtio_bus_destroy_device to virtio_bus_device_unplugged,
  removing the qdev_free, making it take a VirtIODevice and calling it
  from virtio_device_exit

- adding a k->exit callback

virtio_device_exit is still overwritten, the next patches will fix that.

Cc: qemu-stable@nongnu.org
Acked-by: Andreas Faerber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-12-09 21:46:48 +01:00