diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2023-05-16 15:02:36 -0400 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2023-05-30 17:32:02 +0200 |
| commit | 766aa2de0f29b657148e04599320d771c36fd126 (patch) | |
| tree | 911117223771a1574c5a17b938f9beb840aac943 /hw/scsi/trace-events | |
| parent | 1665d9326fd2dd97f1f4061decd67702956ec53c (diff) | |
virtio-scsi: implement BlockDevOps->drained_begin()
The virtio-scsi Host Bus Adapter provides access to devices on a SCSI
bus. Those SCSI devices typically have a BlockBackend. When the
BlockBackend enters a drained section, the SCSI device must temporarily
stop submitting new I/O requests.
Implement this behavior by temporarily stopping virtio-scsi virtqueue
processing when one of the SCSI devices enters a drained section. The
new scsi_device_drained_begin() API allows scsi-disk to message the
virtio-scsi HBA.
scsi_device_drained_begin() uses a drain counter so that multiple SCSI
devices can have overlapping drained sections. The HBA only sees one
pair of .drained_begin/end() calls.
After this commit, virtio-scsi no longer depends on hw/virtio's
ioeventfd aio_set_event_notifier(is_external=true). This commit is a
step towards removing the aio_disable_external() API.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-19-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/scsi/trace-events')
| -rw-r--r-- | hw/scsi/trace-events | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/hw/scsi/trace-events b/hw/scsi/trace-events index ab238293f0..bdd4e2c7c7 100644 --- a/hw/scsi/trace-events +++ b/hw/scsi/trace-events @@ -6,6 +6,8 @@ scsi_req_cancel(int target, int lun, int tag) "target %d lun %d tag %d" scsi_req_data(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d" scsi_req_data_canceled(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d" scsi_req_dequeue(int target, int lun, int tag) "target %d lun %d tag %d" +scsi_bus_drained_begin(void *bus, void *sdev) "bus %p sdev %p" +scsi_bus_drained_end(void *bus, void *sdev) "bus %p sdev %p" scsi_req_continue(int target, int lun, int tag) "target %d lun %d tag %d" scsi_req_continue_canceled(int target, int lun, int tag) "target %d lun %d tag %d" scsi_req_parsed(int target, int lun, int tag, int cmd, int mode, int xfer) "target %d lun %d tag %d command %d dir %d length %d" |