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virtio-scsi: fix ctrl and event handler functions in dataplane mode 

Commit f34e8d8b8d ("virtio-scsi: prepare
virtio_scsi_handle_cmd for dataplane") prepared the virtio-scsi cmd
virtqueue handler function to be used in both the dataplane and
non-datpalane code paths.

It failed to convert the ctrl and event virtqueue handler functions,
which are not designed to be called from the dataplane code path but
will be since the ioeventfd is set up for those virtqueues when
dataplane starts.

Convert the ctrl and event virtqueue handler functions now so they
operate correctly when called from the dataplane code path. Avoid code
duplication by extracting this code into a helper function.

Fixes: f34e8d8b8d ("virtio-scsi: prepare virtio_scsi_handle_cmd for dataplane")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20220427143541.119567-2-stefanha@redhat.com
[Fixed s/by used/be used/ typo pointed out by Michael Tokarev
<mjt@tls.msk.ru>.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2022-04-27 15:35:36 +01:00
parent 71ad4713cc
commit 2f743ef636
1 changed files with 27 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
hw/scsi/virtio-scsi.c
View File

@ -472,16 +472,32 @@ bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
return progress;
}
/*
* If dataplane is configured but not yet started, do so now and return true on
* success.
*
* Dataplane is started by the core virtio code but virtqueue handler functions
* can also be invoked when a guest kicks before DRIVER_OK, so this helper
* function helps us deal with manually starting ioeventfd in that case.
*/
static bool virtio_scsi_defer_to_dataplane(VirtIOSCSI *s)
{
if (!s->ctx || s->dataplane_started) {
return false;
}
virtio_device_start_ioeventfd(&s->parent_obj.parent_obj);
return !s->dataplane_fenced;
}
static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
if (s->ctx) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
if (virtio_scsi_defer_to_dataplane(s)) {
return;
}
virtio_scsi_acquire(s);
virtio_scsi_handle_ctrl_vq(s, vq);
virtio_scsi_release(s);
@ -720,12 +736,10 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
/* use non-QOM casts in the data path */
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
if (s->ctx && !s->dataplane_started) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
if (virtio_scsi_defer_to_dataplane(s)) {
return;
}
virtio_scsi_acquire(s);
virtio_scsi_handle_cmd_vq(s, vq);
virtio_scsi_release(s);
@ -855,12 +869,10 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
if (s->ctx) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
if (virtio_scsi_defer_to_dataplane(s)) {
return;
}
virtio_scsi_acquire(s);
virtio_scsi_handle_event_vq(s, vq);
virtio_scsi_release(s);