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author | Laurent Vivier <lvivier@redhat.com> | 2020-07-27 17:33:19 +0200 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2020-07-27 11:34:50 -0400 |
commit | 0c9753ebda274b0e618d7b4032bb2d83d27483ed (patch) | |
tree | e289473b00bdbc7c56e248e640c09fdbfb2927e2 /hw/virtio/virtio.c | |
parent | d0d89526f70ded5ac41a4c6bb071c0d919b772db (diff) | |
download | qemu-0c9753ebda274b0e618d7b4032bb2d83d27483ed.zip qemu-0c9753ebda274b0e618d7b4032bb2d83d27483ed.tar.gz qemu-0c9753ebda274b0e618d7b4032bb2d83d27483ed.tar.bz2 |
virtio-pci: fix virtio_pci_queue_enabled()
In legacy mode, virtio_pci_queue_enabled() falls back to
virtio_queue_enabled() to know if the queue is enabled.
But virtio_queue_enabled() calls again virtio_pci_queue_enabled()
if k->queue_enabled is set. This ends in a crash after a stack
overflow.
The problem can be reproduced with
"-device virtio-net-pci,disable-legacy=off,disable-modern=true
-net tap,vhost=on"
And a look to the backtrace is very explicit:
...
#4 0x000000010029a438 in virtio_queue_enabled ()
#5 0x0000000100497a9c in virtio_pci_queue_enabled ()
...
#130902 0x000000010029a460 in virtio_queue_enabled ()
#130903 0x0000000100497a9c in virtio_pci_queue_enabled ()
#130904 0x000000010029a460 in virtio_queue_enabled ()
#130905 0x0000000100454a20 in vhost_net_start ()
...
This patch fixes the problem by introducing a new function
for the legacy case and calls it from virtio_pci_queue_enabled().
It also calls it from virtio_queue_enabled() to avoid code duplication.
Fixes: f19bcdfedd53 ("virtio-pci: implement queue_enabled method")
Cc: Jason Wang <jasowang@redhat.com>
Cc: Cindy Lu <lulu@redhat.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20200727153319.43716-1-lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio/virtio.c')
-rw-r--r-- | hw/virtio/virtio.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 546a198..e983025 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -3309,6 +3309,11 @@ hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) return vdev->vq[n].vring.desc; } +bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n) +{ + return virtio_queue_get_desc_addr(vdev, n) != 0; +} + bool virtio_queue_enabled(VirtIODevice *vdev, int n) { BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); @@ -3317,7 +3322,7 @@ bool virtio_queue_enabled(VirtIODevice *vdev, int n) if (k->queue_enabled) { return k->queue_enabled(qbus->parent, n); } - return virtio_queue_get_desc_addr(vdev, n) != 0; + return virtio_queue_enabled_legacy(vdev, n); } hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) |