6b1c41a0f7
commit a7a69ec0d8e4a58be7db88d33cbfa2912807bb2b 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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.