virtio_console: free buffers after reset

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commit a7a69ec0d8 upstream.

Console driver is out of spec. The spec says:
	A driver MUST NOT decrement the available idx on a live
	virtqueue (ie. there is no way to “unexpose” buffers).
and it does exactly that by trying to detach unused buffers
without doing a device reset first.

Defer detaching the buffers until device unplug.

Of course this means we might get an interrupt for
a vq without an attached port now. Handle that by
discarding the consumed buffer.

Reported-by: Tiwei Bie <tiwei.bie@intel.com>
Fixes: b3258ff1d6 ("virtio: Decrement avail idx on buffer detach")
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Michael S. Tsirkin 2018-04-20 20:24:23 +03:00 • committed by Greg Kroah-Hartman

parent 4217a339b3

commit 6b1c41a0f7

1 changed files with 24 additions and 25 deletions

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drivers/char/virtio_console.c

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