Commit Graph

583 Commits

Author SHA1 Message Date
Stefan Hajnoczi a7c8215e3b virtio: disable virtqueue notifications during polling
This is a performance optimization to eliminate vmexits during polling.
It also avoids spurious ioeventfd processing after polling ends.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-12-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03 16:38:50 +00:00
Stefan Hajnoczi aff8fd18f1 virtio: turn vq->notification into a nested counter
Polling should disable virtqueue notifications but that requires nested
virtio_queue_set_notification() calls.  Turn vq->notification into a
counter so it is possible to do nesting.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-10-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03 16:38:49 +00:00
Stefan Hajnoczi 0062ea0fd6 virtio: poll virtqueues for new buffers
Add an AioContext poll handler to detect new virtqueue buffers without
waiting for a guest->host notification.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03 16:38:48 +00:00
Stefan Hajnoczi f6a51c84cd aio: add AioPollFn and io_poll() interface
The new AioPollFn io_poll() argument to aio_set_fd_handler() and
aio_set_event_handler() is used in the next patch.

Keep this code change separate due to the number of files it touches.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03 16:38:48 +00:00
Wei Huang 2858bc6870 virtio: avoid using guest_notifier_mask in vhost-user mode
Because guest mask notifier cannot be used in vhost-user mode, a boolean
flag "use_guest_notifier_mask" was added in commit 5669655aaf to disable
the use of guest mask notifier under virtio-pci. However this flag wasn't
checked in other virtio devices, such as virtio-mmio. In our tests, it
caused assertion error under "vhost-user + virtio-mmio". This patch
addresses this problem by adding a check before guest_notifier_mask is
called.

Signed-off-by: Wei Huang <wei@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-12-16 01:14:54 +02:00
Maxime Coquelin 66d1c4c19f virtio-pci: Fix cross-version migration with older machines
This patch fixes a cross-version migration regression introduced
by commit d1b4259f ("virtio-bus: Plug devices after features are
negotiated").

The problem is encountered when host's vhost backend does not support
VIRTIO_F_VERSION_1, and migration is initiated from a v2.7 or prior
machine with virtio-pci modern capabilities enabled to a v2.8 machine.

In this case, modern capabilities get exposed to the guest by the source,
whereas the target will detect version 1 is not supported so will only
expose legacy capabilities.

The problem is fixed by introducing a new "x-ignore-backend-features"
property, which is set in v2.7 and prior compatibility modes. Doing this,
v2.7 machine keeps its broken behaviour (enabling modern while version
is not supported), and newer machines will behave correctly.

Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-id: 20161214163035.3297-1-maxime.coquelin@redhat.com
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-12-15 07:35:19 +00:00
Gonglei 9730280d54 virtio-crypto: fix uninitialized variables
Though crypto_cfg.reserve is an unused field, let me
initialize the structure in order to make coverity happy.

*** CID 1365923:  Uninitialized variables  (UNINIT)
/hw/virtio/virtio-crypto.c: 851 in virtio_crypto_get_config()
845         stl_le_p(&crypto_cfg.mac_algo_h, c->conf.mac_algo_h);
846         stl_le_p(&crypto_cfg.aead_algo, c->conf.aead_algo);
847         stl_le_p(&crypto_cfg.max_cipher_key_len, c->conf.max_cipher_key_len);
848         stl_le_p(&crypto_cfg.max_auth_key_len, c->conf.max_auth_key_len);
849         stq_le_p(&crypto_cfg.max_size, c->conf.max_size);
850
>>>     CID 1365923:  Uninitialized variables  (UNINIT)
>>>     Using uninitialized value "crypto_cfg". Field "crypto_cfg.reserve"
       is uninitialized when calling "memcpy".
      [Note: The source code implementation of the function
       has been overridden by a builtin model.]
851         memcpy(config, &crypto_cfg, c->config_size);
852     }
853

Rported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-30 04:22:18 +02:00
Paolo Bonzini 83d768b564 virtio: set ISR on dataplane notifications
Dataplane has been omitting forever the step of setting ISR when
an interrupt is raised.  This caused little breakage, because the
specification actually says that ISR may not be updated in MSI mode.

Some versions of the Windows drivers however didn't clear MSI mode
correctly, and proceeded using polling mode (using ISR, not the used
ring index!) for crashdump and hibernation.  If it were just crashdump
and hibernation it would not be a big deal, but recent releases of
Windows do not really shut down, but rather log out and hibernate to
make the next startup faster.  Hence, this manifested as a more serious
hang during shutdown with e.g. Windows 8.1 and virtio-win 1.8.0 RPMs.
Newer versions fixed this, while older versions do not use MSI at all.

The failure has always been there for virtio dataplane, but it became
visible after commits 9ffe337 ("virtio-blk: always use dataplane path
if ioeventfd is active", 2016-10-30) and ad07cd6 ("virtio-scsi: always
use dataplane path if ioeventfd is active", 2016-10-30) made virtio-blk
and virtio-scsi always use the dataplane code under KVM.  The good news
therefore is that it was not a bug in the patches---they were doing
exactly what they were meant for, i.e. shake out remaining dataplane bugs.

The fix is not hard, so it's worth arranging for the broken drivers.
The virtio_should_notify+event_notifier_set pair that is common to
virtio-blk and virtio-scsi dataplane is replaced with a new public
function virtio_notify_irqfd that also sets ISR.  The irqfd emulation
code now need not set ISR anymore, so virtio_irq is removed.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Tested-by: Alex Williamson <alex.williamson@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>
2016-11-18 17:29:25 +02:00
Paolo Bonzini 0687c37c5e virtio: access ISR atomically
This will be needed once dataplane will be able to set it outside
the big QEMU lock.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Tested-by: Alex Williamson <alex.williamson@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>
2016-11-18 17:29:25 +02:00
Paolo Bonzini 310837de6c virtio: introduce grab/release_ioeventfd to fix vhost
Following the recent refactoring of virtio notifiers [1], more specifically
the patch ed08a2a0b ("virtio: use virtio_bus_set_host_notifier to
start/stop ioeventfd") that uses virtio_bus_set_host_notifier [2]
by default, core virtio code requires 'ioeventfd_started' to be set
to true/false when the host notifiers are configured.

When vhost is stopped and started, however, there is a stop followed by
another start. Since ioeventfd_started was never set to true, the 'stop'
operation triggered by virtio_bus_set_host_notifier() will not result
in a call to virtio_pci_ioeventfd_assign(assign=false). This leaves
the memory regions with stale notifiers and results on the next start
triggering the following assertion:

  kvm_mem_ioeventfd_add: error adding ioeventfd: File exists
  Aborted

This patch reintroduces (hopefully in a cleaner way) the concept
that was present with ioeventfd_disabled before the refactoring.
When ioeventfd_grabbed>0, ioeventfd_started tracks whether ioeventfd
should be enabled or not, but ioeventfd is actually not started at
all until vhost releases the host notifiers.

[1] http://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg07748.html
[2] http://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg07760.html

Reported-by: Felipe Franciosi <felipe@nutanix.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Fixes: ed08a2a0b ("virtio: use virtio_bus_set_host_notifier to start/stop ioeventfd")
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Tested-by: Alex Williamson <alex.williamson@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>
2016-11-18 17:29:25 +02:00
Stefan Hajnoczi 600f5ce356 virtio-crypto: fix virtio_queue_set_notification() race
We must check for new virtqueue buffers after re-enabling notifications.
This prevents the race condition where the guest added buffers just
after we stopped popping the virtqueue but before we re-enabled
notifications.

I think the virtio-crypto code was based on virtio-net but this crucial
detail was missed.  virtio-net does not have the race condition because
it processes the virtqueue one more time after re-enabling
notifications.

Cc: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2016-11-18 17:14:10 +02:00
Greg Kurz 435346d748 virtio: drop virtio_queue_get_ring_{size,addr}()
These are not used anymore.

Signed-off-by: Greg Kurz <groug@kaod.org>
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>
2016-11-15 17:20:38 +02:00
Greg Kurz 1cdce7c54d vhost: drop legacy vring layout bits
The legacy vring layout is not used anymore as we use the separate
mappings even for legacy devices.
This patch simply removes it.

This also fixes a bug with virtio 1 devices when the vring descriptor table
is mapped at a higher address than the used vring because the following
function may return an insanely great value:

hwaddr virtio_queue_get_ring_size(VirtIODevice *vdev, int n)
{
    return vdev->vq[n].vring.used - vdev->vq[n].vring.desc +
           virtio_queue_get_used_size(vdev, n);
}

and the mapping fails.

Signed-off-by: Greg Kurz <groug@kaod.org>
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>
2016-11-15 17:20:38 +02:00
Greg Kurz f1f9e6c596 vhost: adapt vhost_verify_ring_mappings() to virtio 1 ring layout
With virtio 1, the vring layout is split in 3 separate regions of
contiguous memory for the descriptor table, the available ring and the
used ring, as opposed with legacy virtio which uses a single region.

In case of memory re-mapping, the code ensures it doesn't affect the
vring mapping. This is done in vhost_verify_ring_mappings() which assumes
the device is legacy.

This patch changes vhost_verify_ring_mappings() to check the mappings of
each part of the vring separately.

This works for legacy mappings as well.

Cc: qemu-stable@nongnu.org
Signed-off-by: Greg Kurz <groug@kaod.org>
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>
2016-11-15 17:20:38 +02:00
Rafael David Tinoco 0d34fbabc1 vhost: migration blocker only if shared log is used
Commit 31190ed7 added a migration blocker in vhost_dev_init() to
check if memfd would succeed. It is better if this blocker first
checks if vhost backend requires shared log. This will avoid a
situation where a blocker is added inappropriately (e.g. shared
log allocation fails when vhost backend doesn't support it).

Signed-off-by: Rafael David Tinoco <rafael.tinoco@canonical.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-15 17:20:37 +02:00
Michael S. Tsirkin 9b706dbbbb virtio: allow per-device-class legacy features
Legacy features are those that transitional devices only
expose on the legacy interface.
Allow different ones per device class.

Cc: qemu-stable@nongnu.org # dependency for the next patch
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-11-15 17:20:36 +02:00
Gonglei 6e724d9d99 virtio-crypto: tag as not hotpluggable and migration
Currently the virtio-crypto device hasn't supported
hotpluggable and live migration well. Let's tag it
as not hotpluggable and migration actively and reopen
them once we support them well.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-15 17:20:36 +02:00
Ladi Prosek bf91bd2792 virtio: make virtqueue_alloc_element static
The function does not fully initialize the returned VirtQueueElement and should
be used only internally from the virtio module.

Signed-off-by: Ladi Prosek <lprosek@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>
2016-11-15 17:20:36 +02:00
Ladi Prosek 27e57efe32 virtio: rename virtqueue_discard to virtqueue_unpop
The function undoes the effect of virtqueue_pop and doesn't do anything
destructive or irreversible so virtqueue_unpop is a more fitting name.

Signed-off-by: Ladi Prosek <lprosek@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>
2016-11-15 17:20:36 +02:00
Gonglei 20cb2ffd5f virtio-crypto: using bh to handle dataq's requests
Make crypto operations are executed asynchronously,
so that other QEMU threads and monitor couldn't
be blocked at the virtqueue handling context.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei d6634ac09a cryptodev: introduce an unified wrapper for crypto operation
We use an opaque point to the VirtIOCryptoReq which
can support different packets based on different
algorithms.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei 04b9b37edd virtio-crypto: add data queue processing handler
Introduces VirtIOCryptoReq structure to store
crypto request so that we can easily support
asynchronous crypto operation in the future.

At present, we only support cipher and algorithm
chaining.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei 59c360ca42 virtio-crypto: add control queue handler
Realize the symmetric algorithm control queue handler,
including plain cipher and chainning algorithms.

Currently the control queue is used to create and
close session for symmetric algorithm.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei 050652d9be virtio-crypto: set capacity of algorithms supported
Expose the capacity of algorithms supported by
virtio crypto device to the frontend driver using
pci configuration space.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei b307d308c9 virtio-crypto-pci: add virtio crypto pci support
This patch adds virtio-crypto-pci, which is the pci proxy for the virtio
crypto device.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Gonglei ea4d8ac2da virtio-crypto: add virtio crypto device emulation
Introduce the virtio crypto realization, I'll
finish the core code in the following patches. The
thoughts came from virtio net realization.

For more information see:
http://qemu-project.org/Features/VirtioCrypto

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-11-01 19:21:08 +02:00
Paolo Bonzini 2bd3c31a60 virtio: inline set_host_notifier_internal
This is only called from virtio_bus_set_host_notifier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 20:06:21 +02:00
Paolo Bonzini fa283a4a8b virtio: inline virtio_queue_set_host_notifier_fd_handler
Of the three possible parameter combinations for
virtio_queue_set_host_notifier_fd_handler:

- assign=true/set_handler=true is only called from
  virtio_device_start_ioeventfd

- assign=false/set_handler=false is called from
  set_host_notifier_internal but it only does something when
  reached from virtio_device_stop_ioeventfd_impl; otherwise
  there is no EventNotifier set on qemu_get_aio_context().

- assign=true/set_handler=false is called from
  set_host_notifier_internal, but it is not doing anything:
  with the new start_ioeventfd and stop_ioeventfd methods,
  there is never an EventNotifier set on qemu_get_aio_context()
  at this point.  This is enforced by the assertion in
  virtio_bus_set_host_notifier.

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>
2016-10-30 20:06:21 +02:00
Paolo Bonzini ed08a2a0ba virtio: use virtio_bus_set_host_notifier to start/stop ioeventfd
ioeventfd_disabled was the only reason for the default
implementation of virtio_device_start_ioeventfd not to use
virtio_bus_set_host_notifier.  This is now fixed, and the sole entry
point to set up ioeventfd can be virtio_bus_set_host_notifier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 20:06:21 +02:00
Paolo Bonzini e616c2f390 virtio: remove ioeventfd_disabled altogether
Now that there is not anymore a switch from the generic ioeventfd handler
to the dataplane handler, virtio_bus_set_host_notifier(assign=true) is
always called with !bus->ioeventfd_started, hence virtio_bus_stop_ioeventfd
does nothing in this case.  Move the invocation to vhost.c, which is the
only place that needs it.

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>
2016-10-30 20:06:20 +02:00
Paolo Bonzini 6019f3b966 virtio: remove set_handler argument from set_host_notifier_internal
Make virtio_device_start_ioeventfd_impl use the same logic as
dataplane to set up the host notifier.  This removes the need
for the set_handler argument in set_host_notifier_internal.

This is a first step towards using virtio_bus_set_host_notifier
as the sole entry point to set up ioeventfds.  At least now
the functions have the same interface, but they still differ
in that virtio_bus_set_host_notifier sets ioeventfd_disabled.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 20:06:20 +02:00
Paolo Bonzini f1ac6a5522 Revert "virtio: Introduce virtio_add_queue_aio"
This reverts commit 872dd82c83.
virtio_add_queue_aio is unused.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 20:06:20 +02:00
Paolo Bonzini 8e93cef14e virtio: introduce virtio_device_ioeventfd_enabled
This will be used to forbid iothread configuration when the
proxy does not allow using ioeventfd.  To simplify the implementation,
change the direction of the ioeventfd_disabled callback too.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 19:51:32 +02:00
Paolo Bonzini ff4c07df67 virtio: add start_ioeventfd and stop_ioeventfd to VirtioDeviceClass
Allow customization of the start and stop of ioeventfd.  This will
allow direct start of dataplane without passing through the default
ioeventfd handlers, which in turn allows using the dataplane logic
instead of virtio_add_queue_aio.  It will also enable some code
simplification, because the sole entry point to ioeventfd setup
will be virtio_bus_set_host_notifier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 19:51:32 +02:00
Paolo Bonzini b13d396227 virtio: move ioeventfd_started flag to VirtioBusState
This simplifies the code and removes the ioeventfd_started
and ioeventfd_set_started callback.  The only difference is
in how virtio-ccw handles an error---it doesn't disable
ioeventfd forever anymore.  It was the only backend to do
so, and if desired this behavior should be implemented in

virtio-bus.c.

Instead of ioeventfd_started, the ioeventfd_assign callback now
determines whether the virtio bus supports host notifiers.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 19:51:32 +02:00
Paolo Bonzini 4ddcc2d5cb virtio: move ioeventfd_disabled flag to VirtioBusState
This simplifies the code and removes the ioeventfd_set_disabled
callback.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
2016-10-30 19:51:32 +02:00
Paolo Bonzini ca2b413c39 virtio: disable ioeventfd as early as possible
Avoid "tricking" virtio-blk-dataplane into thinking that ioeventfd will be
available when it is not.  This bug has always been there, but it will break
TCG+ioeventfd=on once the dataplane code will be always used when ioeventfd=on.

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>
2016-10-30 19:51:31 +02:00
Dr. David Alan Gilbert 019518a80e virtio/migration: Migrate balloon to VMState
Replace the load/save with a vmsd.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-30 19:51:31 +02:00
Dr. David Alan Gilbert ea43e25987 virtio/migration: Add VMStateDescription to VirtioDeviceClass
Provide a vmsd pointer for VirtIO devices to use instead of the
load/save methods.

We'll eventually kill off the load/save methods.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-30 19:51:31 +02:00
Marc-André Lureau 5345fdb446 char: use qemu_chr_fe* functions with CharBackend argument
This also switches from qemu_chr_add_handlers() to
qemu_chr_fe_set_handlers(). Note that qemu_chr_fe_set_handlers() now
takes the focus when fe_open (qemu_chr_add_handlers() did take the
focus)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-16-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24 15:27:21 +02:00
Peter Maydell 627eae7d72 virtio, pc: fixes and features
more guest error handling for virtio devices
 virtio migration rework
 pc fixes
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio, pc: fixes and features

more guest error handling for virtio devices
virtio migration rework
pc fixes

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Mon 10 Oct 2016 00:39:11 BST
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (33 commits)
  intel-iommu: Check IOAPIC's Trigger Mode against the one in IRTE
  virtio: cleanup VMSTATE_VIRTIO_DEVICE
  vhost-vsock: convert VMSTATE_VIRTIO_DEVICE
  virtio-rng: convert VMSTATE_VIRTIO_DEVICE
  virtio-balloon: convert VMSTATE_VIRTIO_DEVICE
  virtio-scsi: convert VMSTATE_VIRTIO_DEVICE
  virtio-input: convert VMSTATE_VIRTIO_DEVICE
  virtio-gpu: convert VMSTATE_VIRTIO_DEVICE
  virtio-serial: convert VMSTATE_VIRTIO_DEVICE
  virtio-9p: convert VMSTATE_VIRTIO_DEVICE
  virtio-net: convert VMSTATE_VIRTIO_DEVICE
  virtio-blk: convert VMSTATE_VIRTIO_DEVICE
  virtio: prepare change VMSTATE_VIRTIO_DEVICE macro
  net: don't poke at chardev internal QemuOpts
  virtio-scsi: handle virtio_scsi_set_config() error
  virtio-scsi: convert virtio_scsi_bad_req() to use virtio_error()
  virtio-net: handle virtio_net_flush_tx() errors
  virtio-net: handle virtio_net_receive() errors
  virtio-net: handle virtio_net_handle_ctrl() error
  virtio-blk: handle virtio_blk_handle_request() errors
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-10-10 16:23:40 +01:00
Halil Pasic 5705653ff8 virtio: cleanup VMSTATE_VIRTIO_DEVICE
Now all the usages of the old version of VMSTATE_VIRTIO_DEVICE are gone,
so we can get rid of the conditionals, and the old macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:43 +03:00
Halil Pasic 81cc8a6566 vhost-vsock: convert VMSTATE_VIRTIO_DEVICE
Use the new VMSTATE_VIRTIO_DEVICE macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:43 +03:00
Halil Pasic b7de81f697 virtio-rng: convert VMSTATE_VIRTIO_DEVICE
Use the new VMSTATE_VIRTIO_DEVICE macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:43 +03:00
Halil Pasic c5dc16b726 virtio-balloon: convert VMSTATE_VIRTIO_DEVICE
Use the new VMSTATE_VIRTIO_DEVICE macro.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:43 +03:00
Halil Pasic 1a665855d7 virtio: prepare change VMSTATE_VIRTIO_DEVICE macro
In most cases the functions passed to VMSTATE_VIRTIO_DEVICE
only call the virtio_load and virtio_save wrappers. Some include some
pre- and post- massaging too. The massaging is better expressed
as such in the VMStateDescription.

Let us prepare for changing the semantic of the VMSTATE_VIRTIO_DEVICE
macro so that it is more similar to the other VMSTATE_*_DEVICE macros
in a sense that it is a field definition.

The preprocessor conditionals are going to be removed as soon as
every usage is converted to the new semantic.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 02:21:42 +03:00
Stefan Hajnoczi 2640d2a5ff virtio: add virtio_detach_element()
During device reset or similar situations a VirtQueueElement needs to be
freed without pushing it onto the used ring or rewinding the virtqueue.
Extract a new function to do this.

Later patches add virtio_detach_element() calls to existing device so
that scatter-gather lists are unmapped and vq->inuse goes back to zero
during device reset.  Currently some devices don't bother and simply
call g_free(elem) which is not a clean way to throw away a
VirtQueueElement.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 01:16:58 +03:00
Liang Li 17871f71fd virtio-balloon: Remove needless precompiled directive
Since there in wrapper around madvise(), the virtio-balloon
code is able to work without the precompiled directive, the
directive can be removed.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Suggested-by: Thomas Huth <thuth@redhat.com>
Reviewd-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10 01:16:57 +03:00
Chen Fan 7a25126d8a virtio: rename the bar index field name in VirtIOPCIProxy
the bar index names are much similar to the bar memory regions,
distinguish them to improve the code readability.

Signed-off-by: Chen Fan <fan.chen@easystack.cn>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-10-08 11:25:29 +03:00
Daniel P. Berrange 331f5eb28a trace: move hw/virtio/virtio-balloon.c trace points into correct file
The trace points for hw/virtio/virtio-balloon.c were mistakenly put
in the top level trace-events file, instead of util/trace-events in

  commit 270ab88f7c
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Thu Jun 16 09:39:57 2016 +0100

    trace: split out trace events for hw/virtio/ directory

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1473872624-23285-5-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-28 19:17:55 +01:00
Stefan Hajnoczi fb1131b674 virtio: handle virtqueue_get_head() errors
Stop processing the vring if virtqueue_get_head() fetches an
out-of-bounds head index.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:56 +03:00
Stefan Hajnoczi 4355c1abca virtio: handle virtqueue_num_heads() errors
If the avail ring index is bogus virtqueue_num_heads() must return
-EINVAL.

The only caller is virtqueue_get_avail_bytes().  Return saying no bytes
are available when virtqueue_num_heads() fails.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:56 +03:00
Stefan Hajnoczi 412e0e81b1 virtio: handle virtqueue_read_next_desc() errors
Stop processing the vring if an avail ring index is invalid.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:56 +03:00
Stefan Hajnoczi b1c7c07f2d virtio: use unsigned int for virtqueue_get_avail_bytes() index
The virtio code uses int, unsigned int, and uint16_t for virtqueue
indices.  The uint16_t is used for the low-level descriptor layout in
virtio_ring.h while code that isn't concerned with descriptor layout can
use unsigned int.

Use of int is problematic because it can result in signed/unsigned
comparison and incompatible int*/unsigned int* pointer types.

Make the virtqueue_get_avail_bytes() 'i' variable unsigned int.  This
eliminates the need to introduce casts and modify code further in the
patches that follow.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:56 +03:00
Stefan Hajnoczi d65abf85e7 virtio: handle virtqueue_get_avail_bytes() errors
If the vring is invalid, tell the caller no bytes are available and mark
the device broken.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:56 +03:00
Stefan Hajnoczi ec55da1924 virtio: handle virtqueue_map_desc() errors
Errors can occur during virtqueue_pop(), especially in
virtqueue_map_desc().  In order to handle this we must unmap iov[]
before returning NULL.  The caller will consider the virtqueue empty and
the virtio_error() call will have marked the device broken.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-23 19:03:55 +03:00
Stefan Hajnoczi 791b1daf72 virtio: migrate vdev->broken flag
Send a subsection if the vdev->broken flag is set.  This allows live
migration of broken virtio devices.

The subsection is only sent if vdev->broken has been set.  In most cases
the flag will be clear and no subsection will be sent.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:55 +03:00
Stefan Hajnoczi f5ed36635d virtio: stop virtqueue processing if device is broken
QEMU prints an error message and exits when the device enters an invalid
state.  Terminating the process is heavy-handed.  The guest may still be
able to function even if there is a bug in a virtio guest driver.

Moreover, exiting is a bug in nested virtualization where a nested guest
could DoS other nested guests by killing a pass-through virtio device.
I don't think this configuration is possible today but it is likely in
the future.

If the broken flag is set, do not process virtqueues or write back used
descriptors.  The broken flag can be cleared again by resetting the
device.

Signed-off-by: Stefan Hajnoczi <stefanha@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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:55 +03:00
Stefan Hajnoczi 8275e2f6be virtio: fix stray tab character
Fix a single occurrence of a tab character in a file that otherwise uses
spaces for indentation.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-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>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23 19:03:55 +03:00
Prasad J Pandit 973e7170dd virtio: add check for descriptor's mapped address
virtio back end uses set of buffers to facilitate I/O operations.
If its size is too large, 'cpu_physical_memory_map' could return
a null address. This would result in a null dereference while
un-mapping descriptors. Add check to avoid it.

Reported-by: Qinghao Tang <luodalongde@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2016-09-23 18:51:40 +03:00
Maxime Coquelin d1b4259f1a virtio-bus: Plug devices after features are negotiated
Currently, devices are plugged before features are negotiated.
If the backend doesn't support VIRTIO_F_VERSION_1, the transport
needs to rewind some settings.

This is the case for CCW, for which a post_plugged callback had
been introduced, where max_rev field is just updated if
VIRTIO_F_VERSION_1 is not supported by the backend.
For PCI, implementing post_plugged would be much more
complicated, so it needs to know whether the backend supports
VIRTIO_F_VERSION_1 at plug time.

Currently, nothing is done for PCI. Modern capabilities get
exposed to the guest even if VIRTIO_F_VERSION_1 is not supported
by the backend, which confuses the guest.

This patch replaces existing post_plugged solution with an
approach that fits with both transports.
Features negotiation is performed before ->device_plugged() call.
A pre_plugged callback is introduced so that the transports can
set their supported features.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com> [ccw]
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
2016-09-15 17:30:03 +03:00
Stefan Hajnoczi fc0b9b0e1c vhost-vsock: add virtio sockets device
Implement the new virtio sockets device for host<->guest communication
using the Sockets API.  Most of the work is done in a vhost kernel
driver so that virtio-vsock can hook into the AF_VSOCK address family.
The QEMU vhost-vsock device handles configuration and live migration
while the rx/tx happens in the vhost_vsock.ko Linux kernel driver.

The vsock device must be given a CID (host-wide unique address):

  # qemu -device vhost-vsock-pci,id=vhost-vsock-pci0,guest-cid=3 ...

For more information see:
http://qemu-project.org/Features/VirtioVsock

[Endianness fixes and virtio-ccw support by Claudio Imbrenda
<imbrenda@linux.vnet.ibm.com>]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[mst: rebase to master]
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-10 00:28:08 +03:00
Michael S. Tsirkin 71d19fc513 virtio-pci: minor refactoring
!legacy && !modern is shorter than !(legacy || modern).
I also perfer this (less ()s) as a matter of taste.

Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-09 20:58:34 +03:00
Jason Wang 96a3d98d2c vhost: don't set vring call if no vector
We used to set vring call fd unconditionally even if guest driver does
not use MSIX for this vritqueue at all. This will cause lots of
unnecessary userspace access and other checks for drivers does not use
interrupt at all (e.g virtio-net pmd). So check and clean vring call
fd if guest does not use any vector for this virtqueue at
all.

Perf diffs (on rx) shows lots of cpus wasted on vhost_signal() were saved:

#
    28.12%  -27.82%  [vhost]           [k] vhost_signal
    14.44%   -1.69%  [kernel.vmlinux]  [k] copy_user_generic_string
     7.05%   +1.53%  [kernel.vmlinux]  [k] __free_page_frag
     6.51%   +5.53%  [vhost]           [k] vhost_get_vq_desc
...

Pktgen tests shows 15.8% improvement on rx pps and 6.5% on tx pps.

Before: RX 2.08Mpps TX 1.35Mpps
After:  RX 2.41Mpps TX 1.44Mpps

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>
2016-09-09 20:58:34 +03:00
Greg Kurz 3eff376977 virtio-pci: error out when both legacy and modern modes are disabled
Without presuming if we got there because of a user mistake or some
more subtle bug in the tooling, it really does not make sense to
implement a non-functional device.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
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
Ladi Prosek 4a1e48beca virtio-balloon: fix stats vq migration
The statistics virtqueue is not migrated properly because virtio-balloon
does not include s->stats_vq_elem in the migration stream.

After migration the statistics virtqueue hangs because the host never
completes the last element (s->stats_vq_elem is NULL on the destination
QEMU).  Therefore the guest never submits new elements and the virtqueue
is hung.

Instead of changing the migration stream format in an incompatible way,
detect the migration case and rewind the virtqueue so the last element
can be completed.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Suggested-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Ladi Prosek <lprosek@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>
2016-09-09 20:58:34 +03:00
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
Ladi Prosek 104e70cae7 virtio-balloon: discard virtqueue element on reset
The one pending element is being freed but not discarded on device
reset, which causes svq->inuse to creep up, eventually hitting the
"Virtqueue size exceeded" error.

Properly discarding the element on device reset makes sure that its
buffers are unmapped and the inuse counter stays balanced.

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: Stefan Hajnoczi <stefanha@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
Stefan Hajnoczi 4b7f91ed02 virtio: zero vq->inuse in virtio_reset()
vq->inuse must be zeroed upon device reset like most other virtqueue
fields.

In theory, virtio_reset() just needs assert(vq->inuse == 0) since
devices must clean up in-flight requests during reset (requests cannot
not be leaked!).

In practice, it is difficult to achieve vq->inuse == 0 across reset
because balloon, blk, 9p, etc implement various different strategies for
cleaning up requests.  Most devices call g_free(elem) directly without
telling virtio.c that the VirtQueueElement is cleaned up.  Therefore
vq->inuse is not decremented during reset.

This patch zeroes vq->inuse and trusts that devices are not leaking
VirtQueueElements across reset.

I will send a follow-up series that refactors request life-cycle across
all devices and converts vq->inuse = 0 into assert(vq->inuse == 0) but
this more invasive approach is not appropriate for stable trees.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Ladi Prosek <lprosek@redhat.com>
2016-09-09 20:58:34 +03:00
Marcel Apfelbaum d9997d89a4 virtio-pci: reduce modern_mem_bar size
Currently each VQ Notification Virtio Capability is allocated
on a different page. The idea is to enable split drivers within
guests, however there are no known plans to do that.
The allocation will result in a 8MB BAR, more than various
guest firmwares pre-allocates for PCI Bridges hotplug process.

Reserve 4 bytes per VQ by default and add a new parameter
"page-per-vq" to be used with split drivers.

Signed-off-by: Marcel Apfelbaum <marcel@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
Michael S. Tsirkin e3aab6c7f3 virtio-pci: use size from correct structure
PIO MR registration should use size from the correct notify struct.
Doesn't affect any visible behaviour because the field values are the
same (both are 4).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-09 20:58:34 +03:00
Thomas Huth a8bba0ada4 virtio: Tell the user what went wrong when event_notifier_init failed
event_notifier_init() can fail in real life, for example when there
are not enough open file handles available (EMFILE) when using a lot
of devices. So instead of leaving the average user with a cryptic
error number only, print out a proper error message with strerror()
instead, so that the user has a better way to figure out what is
going on and that using "ulimit -n" might help here for example.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Eric Blake <eblake@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>
2016-09-09 20:58:34 +03:00
Peter Maydell e00da552a0 virtio: fixes
some bugfixes for virtio
 balloon is still broken wrt migration
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio: fixes

some bugfixes for virtio
balloon is still broken wrt migration

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Tue 23 Aug 2016 17:33:11 BST
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  virtio: decrement vq->inuse in virtqueue_discard()
  virtio: recalculate vq->inuse after migration

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-24 17:21:03 +01:00
Stefan Hajnoczi 58a83c6149 virtio: decrement vq->inuse in virtqueue_discard()
virtqueue_discard() moves vq->last_avail_idx back so the element can be
popped again.  It's necessary to decrement vq->inuse to avoid "leaking"
the element count.

Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@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>
2016-08-23 19:20:24 +03:00
Stefan Hajnoczi bccdef6b1a virtio: recalculate vq->inuse after migration
The vq->inuse field is not migrated.  Many devices don't hold
VirtQueueElements across migration so it doesn't matter that vq->inuse
starts at 0 on the destination QEMU.

At least virtio-serial, virtio-blk, and virtio-balloon migrate while
holding VirtQueueElements.  For these devices we need to recalculate
vq->inuse upon load so the value is correct.

Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@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>
2016-08-23 19:20:10 +03:00
Peter Maydell aba5d97664 -----BEGIN PGP SIGNATURE-----
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 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

# gpg: Signature made Fri 12 Aug 2016 11:48:03 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  trace-events: fix first line comment in trace-events

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-15 18:27:51 +01:00
Michael S. Tsirkin 94c9cb31c0 Revert "vhost-user: Attempt to fix a race with set_mem_table."
This reverts commit 28ed5ef163.

I still think it's the right thing to do, but
tests have been failing sporadically.

Revert for now, and hope to fix it before the release.

Cc: Prerna Saxena <prerna.saxena@nutanix.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Marc-André Lureau <mlureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 1471268075-3425-1-git-send-email-mst@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-15 15:12:21 +01:00
Laurent Vivier e723b87103 trace-events: fix first line comment in trace-events
Documentation is docs/tracing.txt instead of docs/trace-events.txt.

find . -name trace-events -exec \
     sed -i "s?See docs/trace-events.txt for syntax documentation.?See docs/tracing.txt for syntax documentation.?" \
     {} \;

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-id: 1470669081-17860-1-git-send-email-lvivier@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-12 10:36:01 +01:00
Prerna Saxena 28ed5ef163 vhost-user: Attempt to fix a race with set_mem_table.
The set_mem_table command currently does not seek a reply. Hence, there is
no easy way for a remote application to notify to QEMU when it finished
setting up memory, or if there were errors doing so.

As an example:
(1) Qemu sends a SET_MEM_TABLE to the backend (eg, a vhost-user net
application). SET_MEM_TABLE does not require a reply according to the spec.
(2) Qemu commits the memory to the guest.
(3) Guest issues an I/O operation over a new memory region which was configured on (1).
(4) The application has not yet remapped the memory, but it sees the I/O request.
(5) The application cannot satisfy the request because it does not know about those GPAs.

While a guaranteed fix would require a protocol extension (committed separately),
a best-effort workaround for existing applications is to send a GET_FEATURES
message before completing the vhost_user_set_mem_table() call.
Since GET_FEATURES requires a reply, an application that processes vhost-user
messages synchronously would probably have completed the SET_MEM_TABLE before replying.

Signed-off-by: Prerna Saxena <prerna.saxena@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-10 17:47:29 +03:00
Prerna Saxena ca525ce561 vhost-user: Introduce a new protocol feature REPLY_ACK.
This introduces the VHOST_USER_PROTOCOL_F_REPLY_ACK.

If negotiated, client applications should send a u64 payload in
response to any message that contains the "need_reply" bit set
on the message flags. Setting the payload to "zero" indicates the
command finished successfully. Likewise, setting it to "non-zero"
indicates an error.

Currently implemented only for SET_MEM_TABLE.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Prerna Saxena <prerna.saxena@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-10 17:47:29 +03:00
Peter Maydell cbe81c6331 pc, pci, virtio: cleanups, fixes
a bunch of bugfixes and a couple of cleanups
 making these easier and/or making debugging easier
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc, pci, virtio: cleanups, fixes

a bunch of bugfixes and a couple of cleanups
making these easier and/or making debugging easier

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Fri 29 Jul 2016 04:11:01 BST
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (41 commits)
  mptsas: Fix a migration compatible issue
  vhost: do not update last avail idx on get_vring_base() failure
  vhost: add vhost_net_set_backend()
  vhost-user: add error report in vhost_user_write()
  tests: fix vhost-user-test leak
  tests: plug some leaks in virtio-net-test
  vhost-user: wait until backend init is completed
  char: add and use tcp_chr_wait_connected
  char: add chr_wait_connected callback
  vhost: add assert() to check runtime behaviour
  vhost-net: vhost_migration_done is vhost-user specific
  Revert "vhost-net: do not crash if backend is not present"
  vhost-user: add get_vhost_net() assertions
  vhost-user: keep vhost_net after a disconnection
  vhost-user: check vhost_user_{read,write}() return value
  vhost-user: check qemu_chr_fe_set_msgfds() return value
  vhost-user: call set_msgfds unconditionally
  qemu-char: fix qemu_chr_fe_set_msgfds() crash when disconnected
  vhost: use error_report() instead of fprintf(stderr,...)
  vhost: add missing VHOST_OPS_DEBUG
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-07-29 11:57:01 +01:00
Marc-André Lureau 499c557975 vhost: do not update last avail idx on get_vring_base() failure
The state.num value will probably be 0 in this case, but that
doesn't make sense to update.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 05:47:17 +03:00
Marc-André Lureau 950d94ba06 vhost: add vhost_net_set_backend()
Not all vhost-user backends support ops->vhost_net_set_backend(). It is
a nicer to provide an assert/error than to crash trying to
call. Furthermore, it improves a bit the code by hiding vhost_ops
details.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:49 +03:00
Marc-André Lureau f6b8571041 vhost-user: add error report in vhost_user_write()
Similar to vhost_user_read() error report, it is useful to have early
error report.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:49 +03:00
Marc-André Lureau 8695de0fcf vhost: add assert() to check runtime behaviour
All these functions must be called only after the backend is connected.
They are called from virtio-net.c, after either virtio or link status
change.

The check for nc->peer->link_down should ensure vhost_net_{start,stop}()
are always called between vhost_user_{start,stop}().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:48 +03:00
Marc-André Lureau c4843a45e3 vhost-user: check vhost_user_{read,write}() return value
The vhost-user code is quite inconsistent with error handling. Instead
of ignoring some return values of read/write and silently going on with
invalid state (invalid read for example), break the code flow when the
error happened.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:48 +03:00
Marc-André Lureau 6fab2f3f60 vhost-user: check qemu_chr_fe_set_msgfds() return value
Check qemu_chr_fe_set_msgfds() for errors, to make sure the message to
be sent is correct.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:48 +03:00
Marc-André Lureau df3485a148 vhost-user: call set_msgfds unconditionally
It is fine to call set_msgfds() with 0 fd, and ensures any previous fd
array is cleared.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau 4afba63120 vhost: use error_report() instead of fprintf(stderr,...)
Let's use qemu proper error reporting API, this ensures the error is
reported at the right place (stderr or monitor), with a conventional
format.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau c640969216 vhost: add missing VHOST_OPS_DEBUG
Add missing VHOST_OPS_DEBUG() logs, for completeness.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau 162bba7fa8 vhost: do not assert() on vhost_ops failure
Calling a vhost operation may fail, for example with disconnected
vhost-user backend, but qemu shouldn't abort in this case.

Log an error instead, except on error and cleanup code paths where it
can be mostly ignored.

Let's use a VHOST_OPS_DEBUG macro to easily disable those messages once
disconnected backend stabilizes.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau a06db3ec72 vhost: fix calling vhost_dev_cleanup() after vhost_dev_init()
vhost_net_init() calls vhost_dev_init() and in case of failure, calls
vhost_dev_cleanup() directly. However, the structure is already
partially cleaned on error. Calling vhost_dev_cleanup() again will call
vhost_virtqueue_cleanup() on already clean queues, and causing potential
double-close. Instead, adjust dev->nvqs and simplify vhost_dev_init()
code to not call vhost_virtqueue_cleanup() but vhost_dev_cleanup()
instead.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau e0547b59dc vhost: make vhost_dev_cleanup() idempotent
It is called on multiple code path, so make it safe to call several
times (note: I don't remember a reproducer here, but a function called
'cleanup' should probably be idempotent in my book)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Marc-André Lureau 5be5f9be72 vhost: fix cleanup on not fully initialized device
If vhost_dev_init() failed, caller may still call vhost_dev_cleanup()
later. However, vhost_dev_cleanup() tries to remove the device from the
list even if it wasn't yet added, which may lead to crashes. Similarly
for the memory listener.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:46 +03:00
Marc-André Lureau 7b527247f0 vhost: assert the log was cleaned up
Make sure the log was released on cleanup, or it will leak (the
alternative is to call vhost_log_put() unconditionally, but it may hide
some dev state issues).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:46 +03:00
Marc-André Lureau 9e0bc24fa5 vhost: make vhost_log_put() idempotent
Although not strictly required, it is nice to have vhost_log_put()
safely callable multiple times.

Clear dev->log* when calling vhost_log_put() to make the function
idempotent. This also simplifies a bit the caller work.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:46 +03:00
Marc-André Lureau 7cb8a9b9f2 vhost: don't assume opaque is a fd, use backend cleanup
vhost-dev opaque isn't necessarily an fd, it can be a chardev when using
vhost-user. Goto fail, so vhost_backend_cleanup() is called to handle
backend cleanup appropriately.

vhost_set_backend_type() should never fail, use an assert().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:46 +03:00
Prasad J Pandit 1e7aed7014 virtio: check vring descriptor buffer length
virtio back end uses set of buffers to facilitate I/O operations.
An infinite loop unfolds in virtqueue_pop() if a buffer was
of zero size. Add check to avoid it.

Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-29 00:07:10 +03:00
Marcel Apfelbaum 9a4c0e220d hw/virtio-pci: fix virtio behaviour
Enable transitional virtio devices by default.
Enable virtio-1.0 for devices plugged into
PCIe ports (Root ports or Downstream ports).

Using the virtio-1 mode will remove the limitation
of the number of devices that can be attached to a machine
by removing the need for the IO BAR.

Signed-off-by: Marcel Apfelbaum <marcel@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>
2016-07-29 00:07:10 +03:00
Stefan Hajnoczi afd9096eb1 virtio: error out if guest exceeds virtqueue size
A broken or malicious guest can submit more requests than the virtqueue
size permits, causing unbounded memory allocation in QEMU.

The guest can submit requests without bothering to wait for completion
and is therefore not bound by virtqueue size.  This requires reusing
vring descriptors in more than one request, which is not allowed by the
VIRTIO 1.0 specification.

In "3.2.1 Supplying Buffers to The Device", the VIRTIO 1.0 specification
says:

  1. The driver places the buffer into free descriptor(s) in the
     descriptor table, chaining as necessary

and

  Note that the above code does not take precautions against the
  available ring buffer wrapping around: this is not possible since the
  ring buffer is the same size as the descriptor table, so step (1) will
  prevent such a condition.

This implies that placing more buffers into the virtqueue than the
descriptor table size is not allowed.

QEMU is missing the check to prevent this case.  Processing a request
allocates a VirtQueueElement leading to unbounded memory allocation
controlled by the guest.

Exit with an error if the guest provides more requests than the
virtqueue size permits.  This bounds memory allocation and makes the
buggy guest visible to the user.

This patch fixes CVE-2016-5403 and was reported by Zhenhao Hong from 360
Marvel Team, China.

Reported-by: Zhenhao Hong <hongzhenhao@360.cn>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-27 14:04:40 +01:00