With MQ enabled vdpa device and non-MQ supporting guest e.g.
booting vdpa with mq=on over OVMF of single vqp, below assert
failure is seen:
../hw/virtio/vhost-vdpa.c:560: vhost_vdpa_get_vq_index: Assertion `idx >= dev->vq_index
&& idx < dev->vq_index + dev->nvqs' failed.
0 0x00007f8ce3ff3387 in raise () at /lib64/libc.so.6
1 0x00007f8ce3ff4a78 in abort () at /lib64/libc.so.6
2 0x00007f8ce3fec1a6 in __assert_fail_base () at /lib64/libc.so.6
3 0x00007f8ce3fec252 in () at /lib64/libc.so.6
4 0x0000558f52d79421 in vhost_vdpa_get_vq_index (dev=<optimized out>,
idx=<optimized out>) at ../hw/virtio/vhost-vdpa.c:563
5 0x0000558f52d79421 in vhost_vdpa_get_vq_index (dev=<optimized out>,
idx=<optimized out>) at ../hw/virtio/vhost-vdpa.c:558
6 0x0000558f52d7329a in vhost_virtqueue_mask (hdev=0x558f55c01800,
vdev=0x558f568f91f0, n=2, mask=<optimized out>) at ../hw/virtio/vhost.c:1557
7 0x0000558f52c6b89a in virtio_pci_set_guest_notifier
(d=d@entry=0x558f568f0f60, n=n@entry=2, assign=assign@entry=true,
with_irqfd=with_irqfd@entry=false)
at ../hw/virtio/virtio-pci.c:974
8 0x0000558f52c6c0d8 in virtio_pci_set_guest_notifiers (d=0x558f568f0f60,
nvqs=3, assign=true) at ../hw/virtio/virtio-pci.c:1019
9 0x0000558f52bf091d in vhost_net_start (dev=dev@entry=0x558f568f91f0,
ncs=0x558f56937cd0, data_queue_pairs=data_queue_pairs@entry=1, cvq=cvq@entry=1)
at ../hw/net/vhost_net.c:361
10 0x0000558f52d4e5e7 in virtio_net_set_status (status=<optimized out>,
n=0x558f568f91f0) at ../hw/net/virtio-net.c:289
11 0x0000558f52d4e5e7 in virtio_net_set_status (vdev=0x558f568f91f0, status=15
'\017') at ../hw/net/virtio-net.c:370
12 0x0000558f52d6c4b2 in virtio_set_status (vdev=vdev@entry=0x558f568f91f0,
val=val@entry=15 '\017') at ../hw/virtio/virtio.c:1945
13 0x0000558f52c69eff in virtio_pci_common_write (opaque=0x558f568f0f60, addr=<optimized
out>, val=<optimized out>, size=<optimized out>) at ../hw/virtio/virtio-pci.c:1292
14 0x0000558f52d15d6e in memory_region_write_accessor (mr=0x558f568f19d0, addr=20,
value=<optimized out>, size=1, shift=<optimized out>, mask=<optimized out>,
attrs=...)
at ../softmmu/memory.c:492
15 0x0000558f52d127de in access_with_adjusted_size (addr=addr@entry=20,
value=value@entry=0x7f8cdbffe748, size=size@entry=1, access_size_min=<optimized out>,
access_size_max=<optimized out>, access_fn=0x558f52d15cf0
<memory_region_write_accessor>, mr=0x558f568f19d0, attrs=...) at ../softmmu/memory.c:554
16 0x0000558f52d157ef in memory_region_dispatch_write (mr=mr@entry=0x558f568f19d0, addr=20,
data=<optimized out>, op=<optimized out>, attrs=attrs@entry=...)
at ../softmmu/memory.c:1504
17 0x0000558f52d078e7 in flatview_write_continue (fv=fv@entry=0x7f8accbc3b90,
addr=addr@entry=103079215124, attrs=..., ptr=ptr@entry=0x7f8ce6300028, len=len@entry=1,
addr1=<optimized out>, l=<optimized out>, mr=0x558f568f19d0) at
/home/opc/qemu-upstream/include/qemu/host-utils.h:165
18 0x0000558f52d07b06 in flatview_write (fv=0x7f8accbc3b90, addr=103079215124,
attrs=..., buf=0x7f8ce6300028, len=1) at ../softmmu/physmem.c:2822
19 0x0000558f52d0b36b in address_space_write (as=<optimized out>, addr=<optimized
out>, attrs=..., buf=buf@entry=0x7f8ce6300028, len=<optimized out>)
at ../softmmu/physmem.c:2914
20 0x0000558f52d0b3da in address_space_rw (as=<optimized out>, addr=<optimized
out>, attrs=...,
attrs@entry=..., buf=buf@entry=0x7f8ce6300028, len=<optimized out>,
is_write=<optimized out>) at ../softmmu/physmem.c:2924
21 0x0000558f52dced09 in kvm_cpu_exec (cpu=cpu@entry=0x558f55c2da60) at
../accel/kvm/kvm-all.c:2903
22 0x0000558f52dcfabd in kvm_vcpu_thread_fn (arg=arg@entry=0x558f55c2da60) at
../accel/kvm/kvm-accel-ops.c:49
23 0x0000558f52f9f04a in qemu_thread_start (args=<optimized out>) at
../util/qemu-thread-posix.c:556
24 0x00007f8ce4392ea5 in start_thread () at /lib64/libpthread.so.0
25 0x00007f8ce40bb9fd in clone () at /lib64/libc.so.6
The cause for the assert failure is due to that the vhost_dev index
for the ctrl vq was not aligned with actual one in use by the guest.
Upon multiqueue feature negotiation in virtio_net_set_multiqueue(),
if guest doesn't support multiqueue, the guest vq layout would shrink
to a single queue pair, consisting of 3 vqs in total (rx, tx and ctrl).
This results in ctrl_vq taking a different vhost_dev group index than
the default. We can map vq to the correct vhost_dev group by checking
if MQ is supported by guest and successfully negotiated. Since the
MQ feature is only present along with CTRL_VQ, we make sure the index
2 is only meant for the control vq while MQ is not supported by guest.
Fixes: 22288fe ("virtio-net: vhost control virtqueue support")
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
---
hw/net/virtio-net.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index ffb3475..8ca0b80 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3171,8 +3171,17 @@ static NetClientInfo net_virtio_info = {
static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
{
VirtIONet *n = VIRTIO_NET(vdev);
- NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
+ NetClientState *nc;
assert(n->vhost_started);
+ if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
+ if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
+ error_report("virtio-net: bogus vq index ignored");