Add procedure for fast drop of queued packets, acting like
pop and push without mapping the buffers into memory.
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Bring virtio queue to correct internal state for host-to-guest
operations when vhost is temporary stopped.
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Correct recalculation of vq->inuse after migration for the corner case
where the avail_idx has already wrapped but used_idx not yet.
Also change the type of the VirtQueue.inuse to unsigned int. This is
done to be consistent with other members representing sizes (VRing.num),
and because C99 guarantees max ring size < UINT_MAX but does not
guarantee max ring size < INT_MAX.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Fixes: bccdef6b ("virtio: recalculate vq->inuse after migration")
CC: qemu-stable@nongnu.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>
Currently, all virtio devices bypass IOMMU completely. This is because
address_space_memory is assumed and used during DMA emulation. This
patch converts the virtio core API to use DMA API. This idea is
- introducing a new transport specific helper to query the dma address
space. (only pci version is implemented).
- query and use this address space during virtio device guest memory
accessing when iommu platform (VIRTIO_F_IOMMU_PLATFORM) was enabled
for this device.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-block@nongnu.org
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
virtio migrates the low 32 feature bits twice, the first copy is there
for compatibility but ever since
019a3edbb25f1571e876f8af1ce4c55412939e5d: ("virtio: make features 64bit
wide") it's ignored on load. This is wrong since virtio_net_load tests
self announcement and guest offloads before the second copy including
high feature bits is loaded. This means that self announcement, control
vq and guest offloads are all broken after migration.
Fix it up by loading low feature bits: somewhat ugly since high and low
bits become out of sync temporarily, but seems unavoidable for
compatibility. The right thing to do for new features is probably to
test the host features, anyway.
Fixes: 019a3edbb2
("virtio: make features 64bit wide")
Cc: qemu-stable@nongnu.org
Reported-by: Robin Geuze <robing@transip.nl>
Tested-by: Robin Geuze <robing@transip.nl>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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
The effect of this change is the block layer drained section can work,
for example when mirror job is being completed.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All callers pass "false" keeping the old semantics. The windows
implementation doesn't distinguish the flag yet. On posix, it is passed
down to the underlying aio context.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
Yuri Benditovich