Commit Graph

183 Commits

Author SHA1 Message Date
Dongli Zhang
e4fbf5b245 virtio: pass argument by value for virtqueue_map_iovec()
Pass num_sg by value instead of by pointer, as num_sg is never modified in
virtqueue_map_iovec().

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1541139396-4727-1-git-send-email-dongli.zhang@oracle.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-12-11 18:28:46 +01:00
Marc-André Lureau
03fee66fde vmstate: constify VMStateField
Because they are supposed to remain const.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181114132931.22624-1-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-27 15:35:15 +01:00
liujunjie
7da2d99fb9 clean up callback when del virtqueue
Before, we did not clear callback like handle_output when delete
the virtqueue which may result be segmentfault.
The scene is as follows:
1. Start a vm with multiqueue vhost-net,
2. then we write VIRTIO_PCI_GUEST_FEATURES in PCI configuration to
triger multiqueue disable in this vm which will delete the virtqueue.
In this step, the tx_bh is deleted but the callback virtio_net_handle_tx_bh
still exist.
3. Finally, we write VIRTIO_PCI_QUEUE_NOTIFY in PCI configuration to
notify the deleted virtqueue. In this way, virtio_net_handle_tx_bh
will be called and qemu will be crashed.

Although the way described above is uncommon, we had better reinforce it.

CC: qemu-stable@nongnu.org
Signed-off-by: liujunjie <liujunjie23@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-10-19 11:15:03 +08:00
Thomas Huth
c95ac10340 cpu: Provide a proper prototype for target_words_bigendian() in a header
We've got three places already that provide a prototype for this
function in a .c file - that's ugly. Let's provide a proper prototype
in a header instead, with a proper description why this function should
not be used in most cases.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2018-10-17 08:41:43 +02:00
Fam Zheng
2d1df85910 virtio: Return true from virtio_queue_empty if broken
Both virtio-blk and virtio-scsi use virtio_queue_empty() as the
loop condition in VQ handlers (virtio_blk_handle_vq,
virtio_scsi_handle_cmd_vq). When a device is marked broken in
virtqueue_pop, for example if a vIOMMU address translation failed, we
want to break out of the loop.

This fixes a hanging problem when booting a CentOS 3.10.0-862.el7.x86_64
kernel with ATS enabled:

  $ qemu-system-x86_64 \
    ... \
    -device intel-iommu,intremap=on,caching-mode=on,eim=on,device-iotlb=on \
    -device virtio-scsi-pci,iommu_platform=on,ats=on,id=scsi0,bus=pci.4,addr=0x0

The dead loop happens immediately when the kernel boots and initializes
the device, where virtio_scsi_data_plane_handle_cmd will not return:

    > ...
    > #13 0x00005586602b7793 in virtio_scsi_handle_cmd_vq
    > #14 0x00005586602b8d66 in virtio_scsi_data_plane_handle_cmd
    > #15 0x00005586602ddab7 in virtio_queue_notify_aio_vq
    > #16 0x00005586602dfc9f in virtio_queue_host_notifier_aio_poll
    > #17 0x00005586607885da in run_poll_handlers_once
    > #18 0x000055866078880e in try_poll_mode
    > #19 0x00005586607888eb in aio_poll
    > #20 0x0000558660784561 in aio_wait_bh_oneshot
    > #21 0x00005586602b9582 in virtio_scsi_dataplane_stop
    > #22 0x00005586605a7110 in virtio_bus_stop_ioeventfd
    > #23 0x00005586605a9426 in virtio_pci_stop_ioeventfd
    > #24 0x00005586605ab808 in virtio_pci_common_write
    > #25 0x0000558660242396 in memory_region_write_accessor
    > #26 0x00005586602425ab in access_with_adjusted_size
    > #27 0x0000558660245281 in memory_region_dispatch_write
    > #28 0x00005586601e008e in flatview_write_continue
    > #29 0x00005586601e01d8 in flatview_write
    > #30 0x00005586601e04de in address_space_write
    > #31 0x00005586601e052f in address_space_rw
    > #32 0x00005586602607f2 in kvm_cpu_exec
    > #33 0x0000558660227148 in qemu_kvm_cpu_thread_fn
    > #34 0x000055866078bde7 in qemu_thread_start
    > #35 0x00007f5784906594 in start_thread
    > #36 0x00007f5784639e6f in clone

With this patch, virtio_queue_empty will now return 1 as soon as the
vdev is marked as broken, after a "virtio: zero sized buffers are not
allowed" error.

To be consistent, update virtio_queue_empty_rcu as well.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20180910145616.8598-2-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02 18:47:55 +02:00
Paolo Bonzini
db812c4073 virtio: update MemoryRegionCaches when guest negotiates features
Because the cache is sized to include the rings and the event indices,
negotiating the VIRTIO_RING_F_EVENT_IDX feature will result in the size
of the cache changing.  And because MemoryRegionCache accesses are
range-checked, if we skip this we end up with an assertion failure.
This happens with OpenBSD 6.3.

Reported-by: Fam Zheng <famz@redhat.com>
Fixes: 97cd965c07
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-09-07 17:05:18 -04:00
Paolo Bonzini
45641dba38 virtio: free MemoryRegionCache when initialization fails 2018-06-01 14:15:10 +02:00
Tiwei Bie
6f80e6170e virtio: support setting memory region based host notifier
This patch introduces the support for setting memory region
based host notifiers for virtio device. This is helpful when
using a hardware accelerator for a virtio device, because
hardware heavily depends on the notification, this will allow
the guest driver in the VM to notify the hardware directly.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-23 17:01:54 +03:00
Gal Hammer
710fccf80d virtio: improve virtio devices initialization time
The loading time of a VM is quite significant when its virtio
devices use a large amount of virt-queues (e.g. a virtio-serial
device with max_ports=511). Most of the time is spend in the
creation of all the required event notifiers (ioeventfd and memory
regions).

This patch pack all the changes to the memory regions in a
single memory transaction.

Reported-by: Sitong Liu
Reported-by: Xiaoling Gao
Signed-off-by: Gal Hammer <ghammer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
2018-02-08 21:06:40 +02:00
Gal Hammer
76143618a5 virtio: remove event notifier cleanup call on de-assign
The virtio_bus_set_host_notifier function no longer calls
event_notifier_cleanup when a event notifier is removed.

The commit updates the code to match the new behavior and calls
virtio_bus_cleanup_host_notifier after the notifier was de-assign
and no longer in use.

This change is a preparation to allow executing the
virtio_bus_set_host_notifier function in a memory region
transaction.

Signed-off-by: Gal Hammer <ghammer@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-02-08 21:06:26 +02:00
Michael S. Tsirkin
ce3a9eaff4 Revert "virtio: improve virtio devices initialization time"
This reverts commit 6f0bb23072.

This reverts commit f87d72f5c5 as that is
reported to break cleanup and migration.

Cc: Gal Hammer <ghammer@redhat.com>
Cc: Sitong Liu <siliu@redhat.com>
Cc: Xiaoling Gao <xiagao@redhat.com>
Suggested-by: Greg Kurz <groug@kaod.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reported-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
2018-01-24 19:20:19 +02:00
Gal Hammer
6f0bb23072 virtio: improve virtio devices initialization time
The loading time of a VM is quite significant when its virtio
devices use a large amount of virt-queues (e.g. a virtio-serial
device with max_ports=511). Most of the time is spend in the
creation of all the required event notifiers (ioeventfd and memory
regions).

This patch pack all the changes to the memory regions in a
single memory transaction.

Reported-by: Sitong Liu <siliu@redhat.com>
Reported-by: Xiaoling Gao <xiagao@redhat.com>
Signed-off-by: Gal Hammer <ghammer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:38 +02:00
Michael S. Tsirkin
8fc47c876d virtio_error: don't invoke status callbacks
Backends don't need to know what frontend requested a reset,
and notifying then from virtio_error is messy because
virtio_error itself might be invoked from backend.

Let's just set the status directly.

Cc: qemu-stable@nongnu.org
Reported-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-12-19 23:41:00 +02:00
Prasad J Pandit
758ead31c7 virtio: check VirtQueue Vring object is set
A guest could attempt to use an uninitialised VirtQueue object
or unset Vring.align leading to a arithmetic exception. Add check
to avoid it.

Reported-by: Zhangboxian <zhangboxian@huawei.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: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2017-12-01 19:05:58 +02:00
Maxime Coquelin
2d4ba6cc74 virtio: Add queue interface to restore avail index from vring used index
In case of backend crash, it is not possible to restore internal
avail index from the backend value as vhost_get_vring_base
callback fails.

This patch provides a new interface to restore internal avail index
from the vring used index, as done by some vhost-user backend on
reconnection.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-12-01 19:05:58 +02:00
linzhecheng
7abea552ab fix: unrealize virtio device if we fail to hotplug it
If we fail to hotplug virtio-blk device and then suspend
or shutdown VM, qemu is likely to crash.

Re-production steps:
1. Run VM named vm001
2. Create a virtio-blk.xml which contains wrong configurations:
<disk device="lun" rawio="yes" type="block">
  <driver cache="none" io="native" name="qemu" type="raw" />
  <source dev="/dev/mapper/11-dm" />
  <target bus="virtio" dev="vdx" />
</disk>
3. Run command : virsh attach-device vm001 virtio-blk.xml
error: Failed to attach device from blk-scsi.xml
error: internal error: unable to execute QEMU command 'device_add': Please set scsi=off for virtio-blk devices in order to use virtio 1.0
it means hotplug virtio-blk device failed.
4. Suspend or shutdown VM will leads to qemu crash

Problem happens in virtio_vmstate_change which is called by
vm_state_notify:
vdev’s parent_bus is NULL, so qdev_get_parent_bus(DEVICE(vdev)) will crash.
virtio_vmstate_change is added to the list vm_change_state_head at virtio_blk_device_realize(virtio_init),
but after hotplug virtio-blk failed, virtio_vmstate_change will not be removed from vm_change_state_head.
Adding unrealize function of virtio-blk device can solve this problem.

Signed-off-by: linzhecheng <linzhecheng@huawei.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>
2017-11-16 17:46:53 +02:00
Wolfgang Bumiller
37ef70be6a virtio: fix descriptor counting in virtqueue_pop
While changing the s/g list allocation, commit 3b3b0628
also changed the descriptor counting to count iovec entries
as split by cpu_physical_memory_map(). Previously only the
actual descriptor entries were counted and the split into
the iovec happened afterwards in virtqueue_map().
Count the entries again instead to avoid erroneous
"Looped descriptor" errors.

Reported-by: Hans Middelhoek <h.middelhoek@ospito.nl>
Link: https://forum.proxmox.com/threads/vm-crash-with-memory-hotplug.35904/
Fixes: 3b3b062821 ("virtio: slim down allocation of VirtQueueElements")
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-10-15 05:54:44 +03:00
Dr. David Alan Gilbert
2f168d0708 migration: Route more error paths
vmstate_save_state is called in lots of places.
Route error returns from the easier cases back up;  there are lots
of more complex cases where their own error paths need fixing.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170925112917.21340-7-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Commit message fix up as Peter's review
2017-09-27 11:44:18 +01:00
Eric Blake
262a69f428 osdep.h: Prohibit disabling assert() in supported builds
We already have several files that knowingly require assert()
to work, sometimes because refactoring the code for proper
error handling has not been tackled yet; there are probably
other files that have a similar situation but with no comments
documenting the same.  In fact, we have places in migration
that handle untrusted input with assertions, where disabling
the assertions risks a worse security hole than the current
behavior of losing the guest to SIGABRT when migration fails
because of the assertion.  Promote our current per-file
safety-valve to instead be project-wide, and expand it to also
cover glib's g_assert().

Note that we do NOT want to encourage 'assert(side-effects);'
(that is a bad practice that prevents copy-and-paste of code to
other projects that CAN disable assertions; plus it costs
unnecessary reviewer mental cycles to remember whether a project
special-cases the crippling of asserts); and we would LIKE to
fix migration to not rely on asserts (but that takes a big code
audit).  But in the meantime, we DO want to send a message
that anyone that disables assertions has to tweak code in order
to compile, making it obvious that they are taking on additional
risk that we are not going to support.  At the same time, leave
comments mentioning NDEBUG in files that we know still need to
be scrubbed, so there is at least something to grep for.

It would be possible to come up with some other mechanism for
doing runtime checking by default, but which does not abort
the program on failure, while leaving side effects in place
(unlike how crippling assert() avoids even the side effects),
perhaps under the name q_verify(); but it was not deemed worth
the effort (developers should not have to learn a replacement
when the standard C macro works just fine, and it would be a lot
of churn for little gain).  The patch specifically uses #error
rather than #warn so that a user is forced to tweak the header
to acknowledge the issue, even when not using a -Werror
compilation.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>

Message-Id: <20170911211320.25385-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 16:20:49 +02:00
Paolo Bonzini
b0ac429f13 virtio: add virtqueue_alloc_element tracepoint
This tracepoint can help diagnosing failures due to memory
fragmentation in the guest.

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>
2017-06-02 18:57:17 +03:00
Juan Quintela
68ba3b0743 migration: migration.h was not needed
This files don't use any function from migration.h, so drop it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
2017-05-18 19:20:59 +02:00
Greg Kurz
66453cff9e virtio: allow broken device to notify guest
According to section 2.1.2 of the virtio-1 specification:

"The device SHOULD set DEVICE_NEEDS_RESET when it enters an error state that
a reset is needed. If DRIVER_OK is set, after it sets DEVICE_NEEDS_RESET,
the device MUST send a device configuration change notification to the
driver."

Commit "f5ed36635d8f virtio: stop virtqueue processing if device is broken"
introduced a virtio_error() call that just does that:

- internally mark the device as broken
- set the DEVICE_NEEDS_RESET bit in the status
- send a configuration change notification

Unfortunately, virtio_notify_vector(), called by virtio_notify_config(),
returns right away when the device is marked as broken and the notification
isn't sent in this case.

The spec doesn't say whether a broken device can send notifications
in other situations or not. But since the driver isn't supposed to do
anything but to reset the device, it makes sense to keep the check in
virtio_notify_config().

Marking the device as broken AFTER the configuration change notification was
sent is enough to fix the issue.

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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-18 00:35:15 +03:00
Paolo Bonzini
e49a661840 virtio: always use handle_aio_output if registered
Commit ad07cd6 ("virtio-scsi: always use dataplane path if ioeventfd is
active", 2016-10-30) and 9ffe337 ("virtio-blk: always use dataplane
path if ioeventfd is active", 2016-10-30) broke the virtio 1.0
indirect access registers.

The indirect access registers bypass the ioeventfd, so that virtio-blk
and virtio-scsi now repeatedly try to initialize dataplane instead of
triggering the guest->host EventNotifier.  Detect the situation by
checking vq->handle_aio_output; if it is not NULL, trigger the
EventNotifier, which is how the device expects to get notifications
and in fact the only thread-safe manner to deliver them.

Fixes: ad07cd6
Fixes: 9ffe337
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-03-22 17:56:00 +02:00
Jason Wang
e45da65322 virtio: validate address space cache during init
We don't check the return value of address_space_cache_init(), this
may lead buggy driver use incorrect region caches. Instead of
triggering an assert, catch and warn this early in
virtio_init_region_cache().

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-15 19:37:19 +02:00
Jason Wang
e0e2d64409 virtio: destroy region cache during reset
We don't destroy region cache during reset which can make the maps
of previous driver leaked to a buggy or malicious driver that don't
set vring address before starting to use the device. Fix this by
destroy the region cache during reset and validate it before trying to
see them.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-15 19:37:19 +02:00
Jason Wang
168e4af3c1 virtio: guard against NULL pfn
To avoid access stale memory region cache after reset, this patch
check the existence of virtqueue pfn for all exported virtqueue access
helpers before trying to use them.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-15 19:37:19 +02:00
Stefan Hajnoczi
874adf45db virtio: add missing region cache init in virtio_load()
Commit 97cd965c07 ("virtio: use
VRingMemoryRegionCaches for avail and used rings") switched to a memory
region cache to avoid repeated map/unmap operations.

The virtio_load() process is a little tricky because vring addresses are
serialized in two separate places.  VIRTIO 1.0 devices serialize desc
and then a subsection with used and avail.  Legacy devices only
serialize desc.

Live migration of VIRTIO 1.0 devices fails on the destination host with:

  VQ 0 size 0x80 < last_avail_idx 0x12f8 - used_idx 0x0
  Failed to load virtio-blk:virtio
  error while loading state for instance 0x0 of device '0000:00:04.0/virtio-blk'

This happens because the memory region cache is only initialized after
desc is loaded and not after the used and avail subsection is loaded.
If the guest chose memory addresses that don't match the legacy ring
layout then the wrong guest memory location is accessed.

Wait until all ring addresses are known before trying to initialize the
region cache.  Also clarify the incomplete comment about VIRTIO-1 ring
address subsection.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
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>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
2017-03-02 07:14:28 +02:00
Stefan Hajnoczi
3cdf847329 virtio: invalidate memory in vring_set_avail_event()
Remember to invalidate the avail event field so the memory pages are
marked dirty.

Cc: Paolo Bonzini <pbonzini@redhat.com>
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>
Tested-by: Eric Auger <eric.auger@redhat.com>
2017-03-02 07:14:27 +02:00
Cornelia Huck
34c6bf22a8 virtio: guard vring access when setting notification
Switching to vring caches exposed an existing bug in
virtio_queue_set_notification(): We can't access vring structures
if they have not been set up yet. This may happen, for example,
for virtio-blk devices with multiple queues: The code will try to
switch notifiers for every queue, but the guest may have only set up
a subset of them.

Fix this by guarding access to the vring memory by checking for
vring.desc. The first aio poll will iron out any remaining
inconsistencies for later-configured queues (buggy legacy drivers).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-02 07:14:27 +02:00
Paolo Bonzini
dd3dd4ba7b virtio: check for vring setup in virtio_queue_empty
If the vring has not been set up, there is nothing in the virtqueue.
virtio_queue_host_notifier_aio_poll calls virtio_queue_empty even in
this case; we have to filter it out just like virtio_queue_notify_aio_vq.

Reported-by: Gerd Hoffmann <kraxel@redhat.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>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-03-02 07:14:27 +02:00
Michael S. Tsirkin
b4b9862b53 virtio: Fix no interrupt when not creating msi controller
For ARM virt machine, if we use virt-2.7 which will not create ITS node,
the virtio-net can not recieve interrupts so it can't get ip address
through dhcp.
This fixes commit 83d768b(virtio: set ISR on dataplane notifications).

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
97cd965c07 virtio: use VRingMemoryRegionCaches for avail and used rings
The virtio-net change is necessary because it uses virtqueue_fill
and virtqueue_flush instead of the more convenient virtqueue_push.

Reviewed-by: Stefan Hajnoczi <stefanha@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>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
ca0176ad83 virtio: check for vring setup in virtio_queue_update_used_idx
If the vring has not been set up, it is not necessary for vring_used_idx
to do anything (as is already the case when the caller is virtio_load).
This is harmless for now, but it will be a problem when the
MemoryRegionCache has not been set up.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
991976f751 virtio: use VRingMemoryRegionCaches for descriptor ring
Reviewed-by: Stefan Hajnoczi <stefanha@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>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
c611c76417 virtio: add MemoryListener to cache ring translations
The cached translations are RCU-protected to allow efficient use
when processing virtqueues.

Reviewed-by: Stefan Hajnoczi <stefanha@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>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
5eba0404b9 virtio: use MemoryRegionCache to access descriptors
For now, the cache is created on every virtqueue_pop.  Later on,
direct descriptors will be able to reuse it.

Reviewed-by: Stefan Hajnoczi <stefanha@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>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
9796d0ac8f virtio: use address_space_map/unmap to access descriptors
This makes little difference, but it makes the code change smaller
for the next patch that introduces MemoryRegionCache.  This is
because map/unmap are similar to MemoryRegionCache init/destroy.

Reviewed-by: Stefan Hajnoczi <stefanha@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>
2017-02-17 21:52:30 +02:00
Fam Zheng
0793169870 virtio: Report real progress in VQ aio poll handler
In virtio_queue_host_notifier_aio_poll, not all "!virtio_queue_empty()"
cases are making true progress.

Currently the offending one is virtio-scsi event queue, whose handler
does nothing if no event is pending. As a result aio_poll() will spin on
the "non-empty" VQ and take 100% host CPU.

Fix this by reporting actual progress from virtio queue aio handlers.

Reported-by: Ed Swierk <eswierk@skyportsystems.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Tested-by: Ed Swierk <eswierk@skyportsystems.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>
2017-02-17 21:52:30 +02:00
Paolo Bonzini
c25d97c4ff virtio: make virtio_should_notify static
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-01 03:37:18 +02:00
Jianjun Duan
2c21ee769e migration: extend VMStateInfo
Current migration code cannot handle some data structures such as
QTAILQ in qemu/queue.h. Here we extend the signatures of put/get
in VMStateInfo so that customized handling is supported. put now
will return int type.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-by: Jianjun Duan <duanj@linux.vnet.ibm.com>
Message-Id: <1484852453-12728-2-git-send-email-duanj@linux.vnet.ibm.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-01-24 17:54:47 +00:00
Peter Maydell
598cf1c805 * QOM interface fix (Eduardo)
* RTC fixes (Gaohuai, Igor)
 * Memory leak fixes (Li Qiang, me)
 * Ctrl-a b regression (Marc-André)
 * Stubs cleanups and fixes (Leif, me)
 * hxtool tweak (me)
 * HAX support (Vincent)
 * QemuThread, exec.c and SCSI fixes (Roman, Xinhua, me)
 * PC_COMPAT_2_8 fix (Marcelo)
 * stronger bitmap assertions (Peter)
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* QOM interface fix (Eduardo)
* RTC fixes (Gaohuai, Igor)
* Memory leak fixes (Li Qiang, me)
* Ctrl-a b regression (Marc-André)
* Stubs cleanups and fixes (Leif, me)
* hxtool tweak (me)
* HAX support (Vincent)
* QemuThread, exec.c and SCSI fixes (Roman, Xinhua, me)
* PC_COMPAT_2_8 fix (Marcelo)
* stronger bitmap assertions (Peter)

# gpg: Signature made Fri 20 Jan 2017 12:49:01 GMT
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (35 commits)
  pc.h: move x-mach-use-reliable-get-clock compat entry to PC_COMPAT_2_8
  bitmap: assert that start and nr are non negative
  Revert "win32: don't run subprocess tests on Mingw32 platform"
  hax: add Darwin support
  Plumb the HAXM-based hardware acceleration support
  target/i386: Add Intel HAX files
  kvm: move cpu synchronization code
  KVM: PPC: eliminate unnecessary duplicate constants
  ramblock-notifier: new
  char: fix ctrl-a b not working
  exec: Add missing rcu_read_unlock
  x86: ioapic: fix fail migration when irqchip=split
  x86: ioapic: dump version for "info ioapic"
  x86: ioapic: add traces for ioapic
  hxtool: emit Texinfo headings as @subsection
  qemu-thread: fix qemu_thread_set_name() race in qemu_thread_create()
  serial: fix memory leak in serial exit
  scsi-block: fix direction of BYTCHK test for VERIFY commands
  pc: fix crash in rtc_set_memory() if initial cpu is marked as hotplugged
  acpi: filter based on CONFIG_ACPI_X86 rather than TARGET
  ...

# Conflicts:
#	include/hw/i386/pc.h
2017-01-20 16:42:07 +00:00
Peter Maydell
d1c82f7cc3 First set of s390x patches for 2.9:
- rework of the zpci code, giving us proper multibus support
 - introduction of the 2.9 machine
 - fixes and improvements
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Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20170120-v2' into staging

First set of s390x patches for 2.9:
- rework of the zpci code, giving us proper multibus support
- introduction of the 2.9 machine
- fixes and improvements

# gpg: Signature made Fri 20 Jan 2017 09:11:58 GMT
# gpg:                using RSA key 0xDECF6B93C6F02FAF
# gpg: Good signature from "Cornelia Huck <huckc@linux.vnet.ibm.com>"
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>"
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* remotes/cohuck/tags/s390x-20170120-v2:
  virtio-ccw: fix ring sizing
  s390x/pci: merge msix init functions
  s390x/pci: handle PCIBridge bus number
  s390x/pci: use hashtable to look up zpci via fh
  s390x/pci: PCI multibus bridge handling
  s390x/pci: optimize calling s390_get_phb()
  s390x/pci: change the device array to a list
  s390x/pci: dynamically allocate iommu
  s390x/pci: make S390PCIIOMMU inherit Object
  s390x/kvm: use kvm_gsi_routing_enabled in flic
  s390x: add compat machine for 2.9
  s390x: remove double compat statement

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-20 15:53:58 +00:00
Michael S. Tsirkin
8c797e758a virtio-ccw: fix ring sizing
Current code seems to assume ring size is
always decreased but this is not required by spec:
what spec says is just that size can not exceed
the maximum. Fix it up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <1484256243-1982-1-git-send-email-mst@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-01-20 10:02:02 +01:00
Michael S. Tsirkin
6bdc21c050 virtio: fix up max size checks
Coverity reports that ARRAY_SIZE(elem->out_sg) (and all the others too)
is wrong because elem->out_sg is a pointer.

However, the check is not in the right place and the max_size argument
of virtqueue_map_iovec can be removed.  The check on in_num/out_num
should be moved to qemu_get_virtqueue_element instead, before the call
to virtqueue_alloc_element.

Cc: qemu-stable@nongnu.org
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Fixes: 3724650db0 ("virtio: introduce virtqueue_alloc_element")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-01-19 23:00:31 +02:00
Stefan Hajnoczi
1448c133e1 virtio: disable notifications again after poll succeeded
While AioContext is in polling mode virtqueue notifications are not
necessary.  Some device virtqueue handlers enable notifications.  Make
sure they stay disabled to avoid unnecessary vmexits.

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>
Tested-by: Richard Henderson <rth@twiddle.net>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-01-18 22:59:53 +02:00
Stefan Hajnoczi
332fa82d09 Revert "virtio: turn vq->notification into a nested counter"
This reverts commit aff8fd18f1.

Both virtio-net and virtio-crypto do not balance
virtio_queue_set_notification() enable and disable calls.  This makes
the notifications_disabled counter unreliable and Doug Goldstein
reported the following assertion failure:

  #3  0x00007ffff44d1c62 in __GI___assert_fail (
      assertion=assertion@entry=0x555555ae8e8a "vq->notification_disabled > 0",
      file=file@entry=0x555555ae89c0 "/home/doug/work/qemu/hw/virtio/virtio.c",
      line=line@entry=215,
      function=function@entry=0x555555ae9630 <__PRETTY_FUNCTION__.43707>
      "virtio_queue_set_notification") at assert.c:101
  #4  0x00005555557f25d6 in virtio_queue_set_notification (vq=0x55555666aa90,
      enable=enable@entry=1) at /home/doug/work/qemu/hw/virtio/virtio.c:215
  #5  0x00005555557dc311 in virtio_net_has_buffers (q=<optimized out>,
      q=<optimized out>, bufsize=102)
      at /home/doug/work/qemu/hw/net/virtio-net.c:1008
  #6  virtio_net_receive (nc=<optimized out>, buf=0x555557386b88 "", size=102)
      at /home/doug/work/qemu/hw/net/virtio-net.c:1148
  #7  0x00005555559cad33 in nc_sendv_compat (flags=<optimized out>, iovcnt=1,
      iov=0x7fffead746d0, nc=0x55555788b340) at net/net.c:705
  #8  qemu_deliver_packet_iov (sender=<optimized out>, flags=<optimized out>,
      iov=0x7fffead746d0, iovcnt=1, opaque=0x55555788b340) at net/net.c:732
  #9  0x00005555559cd929 in qemu_net_queue_deliver (size=<optimized out>,
      data=<optimized out>, flags=<optimized out>, sender=<optimized out>,
      queue=0x55555788b550) at net/queue.c:164
  #10 qemu_net_queue_flush (queue=0x55555788b550) at net/queue.c:261

This patch is safe to revert since it's just an optimization for
virtqueue polling.  The next patch will improve the situation again
without resorting to nesting.

Reported-by: Doug Goldstein <cardoe@cardoe.com>
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>
Tested-by: Richard Henderson <rth@twiddle.net>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-01-18 22:59:53 +02:00
Paolo Bonzini
d6da1e9eca event_notifier: cleanups around event_notifier_set_handler
Remove the useless is_external argument.  Since the iohandler
AioContext is never used for block devices, aio_disable_external
is never called on it.  This lets us remove stubs/iohandler.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-16 17:52:35 +01:00
Yuri Benditovich
54e17709ac virtio: Introduce virtqueue_drop_all procedure
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>
2017-01-10 07:02:53 +02:00
Yuri Benditovich
312d3b3534 net: Add virtio queue interface to update used index from vring state
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>
2017-01-10 07:02:53 +02:00
Halil Pasic
e66bcc4081 virtio: fix vq->inuse recalc after migr
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>
2017-01-10 07:02:52 +02:00