From: Mike Christie Date: Sun, 22 Feb 2026 23:27:04 +0000 (-0600) Subject: scsi: vhost-scsi: Report direction completion support X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a4d72d2dd0cbc3ff20f66a9168dd68b191c57409;p=thirdparty%2Fkernel%2Fstable.git scsi: vhost-scsi: Report direction completion support This has vhost-scsi report that it supports direct completions. When using a worker task per queue or group of queues with fast backends then enabling direct completion and submissions increases performance 20-30% with workloads like: fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=8K \ --ioengine=libaio --iodepth=128 --numjobs=$jobs As jobs matches and passes the number of vCPUs in the VM then the benefit increases. However, when using a single worker then queueing completions and submissions is best as the worker is busy handling mapping data and setting/tearing down commands. Signed-off-by: Mike Christie Link: https://patch.msgid.link/20260222232946.7637-5-michael.christie@oracle.com Signed-off-by: Martin K. Petersen --- diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 903d4c5be2b2..9a1253b9d8c5 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -2951,6 +2951,7 @@ static const struct target_core_fabric_ops vhost_scsi_ops = { .tfc_tpg_attrib_attrs = vhost_scsi_tpg_attrib_attrs, .default_compl_type = TARGET_QUEUE_COMPL, + .direct_compl_supp = 1, .default_submit_type = TARGET_QUEUE_SUBMIT, .direct_submit_supp = 1, };