This patch fixes a problem in handling task management functions
in virtio-scsi. The cause of the problem is a mismatch between
the size of the tag in QEMU (32-bit) and virtio-scsi (64-bit).
Changing the QEMU size is hard because the migration format
uses 32 bits to store the tag; so just don't use the QEMU tag
(virtio-scsi only uses the tag for task management functions
anyway) and look up the full 64-bit tag in the hba_private field.
The reproducer is a bit obscure. If you cause an I/O timeout
(for example with rerror=stop and doing 'cont' on the monitor
continuously without fixing the error), sooner or later the
guest will try to abort the command and reissue it. At this
point, QEMU will report _two_ errors instead of one when you
hit 'c', because the first error has not been canceled correctly.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When an event is reported but no buffers are present in the event vq,
we can set a flag and report a dummy event as soon as one is added.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Implement the hotplug() and hot_unplug() interfaces in virtio-scsi, by signal
the virtio_scsi.ko in guest kernel via event virtual queue.
The counterpart patch of virtio_scsi.ko will be sent soon in another thread.
Signed-off-by: Sen Wang <senwang@linux.vnet.ibm.com>
Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com>
[ Add memset, fix LUN field, placate checkpatch - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The event queue is not supported yet and the handler does not
have to do much anyway when buffers are added. However, the
handler is called unconditionally by the virtio layer, and this
results in a crash as soon as buffers are added to the event
queue because we pass NULL.
Reported-by: Bryan Venteicher <bryanv@daemoninthecloset.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make qbus children show up as link<> properties. There is no stable
addressing for qbus children so we use an unstable naming convention.
This is okay in QOM though because the composition name is expected to
be what's stable.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Adding multiqueue is as simple as creating more than one virtqueues,
and saving the queue number for each request.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to restore requests correctly from a multitude of virtqueues,
we need to store the id of the request queue that each request came
from.
Do this even for single-queue, by storing a hard-coded zero, to
simplify future implementation of multiqueue.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
