On Fri, Sep 30, 2016 at 05:13:40PM +0200, Greg Kurz wrote: > The virtio_scsi_bad_req() function is called when a guest sends a > request with missing or ill-sized headers. This generally happens > when the virtio_scsi_parse_req() function returns an error. > > With this patch, virtio_scsi_bad_req() will mark the device as broken, > detach the request from the virtqueue and free it, instead of forcing > QEMU to exit. > > In nearly all locations where virtio_scsi_bad_req() is called, the only > thing to do next is to return to the caller. > > The virtio_scsi_handle_cmd_req_prepare() function is an exception though. > > It is called in a loop by virtio_scsi_handle_cmd_vq() and passed requests > freshly popped from a cmd virtqueue; virtio_scsi_handle_cmd_req_prepare() > does some sanity checks on the request and returns a boolean flag to > indicate whether the request should be queued or not. In the latter case, > virtio_scsi_handle_cmd_req_prepare() has detected a non-fatal error and > sent a response back to the guest. > > We have now a new condition to take into account: the device is broken > and should stop all processing. > > The return value of virtio_scsi_handle_cmd_req_prepare() is hence changed > to an int. A return value of zero means that the request should be queued. > Other non-fatal error cases where the request shoudn't be queued return > a negative errno (values are vaguely inspired by the error condition, but > the only goal here is to discriminate the case we're interested in). > > And finally, if virtio_scsi_bad_req() was called, -EINVAL is returned. In > this case, virtio_scsi_handle_cmd_vq() detaches and frees already queued > requests, instead of submitting them. > > Signed-off-by: Greg Kurz <gr...@kaod.org> > --- > v4: - fixed success return value in virtio_scsi_handle_cmd_req_prepare() > - fixed typo in changelog > --- > hw/scsi/virtio-scsi.c | 46 ++++++++++++++++++++++++++++++++-------------- > 1 file changed, 32 insertions(+), 14 deletions(-)
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
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