From 59b701b99e2d01245b951325a8c3c12faa98d3ea Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Fri, 15 Mar 2024 19:47:01 -0500 Subject: [PATCH] vhost-scsi: Use system wq to flush dev for TMFs We flush all the workers that are not also used by the ctl vq to make sure that responses queued by LIO before the TMF response are sent before the TMF response. This requires a special vhost_vq_flush function which, in the next patches where we handle SIGKILL killing workers while in use, will require extra locking/complexity. To avoid that, this patch has us flush the entire device from the system work queue, then queue up sending the response from there. This is a little less optimal since we now flush all workers but this will be ok since commands have already timed out and perf is not a concern. Signed-off-by: Mike Christie Message-Id: <20240316004707.45557-4-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin --- drivers/vhost/scsi.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 6ec1abe7364f..04e0d3f1bd77 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -210,6 +210,7 @@ struct vhost_scsi { struct vhost_scsi_tmf { struct vhost_work vwork; + struct work_struct flush_work; struct vhost_scsi *vhost; struct vhost_scsi_virtqueue *svq; @@ -373,9 +374,8 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd) if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) { struct vhost_scsi_tmf *tmf = container_of(se_cmd, struct vhost_scsi_tmf, se_cmd); - struct vhost_virtqueue *vq = &tmf->svq->vq; - vhost_vq_work_queue(vq, &tmf->vwork); + schedule_work(&tmf->flush_work); } else { struct vhost_scsi_cmd *cmd = container_of(se_cmd, struct vhost_scsi_cmd, tvc_se_cmd); @@ -1287,33 +1287,31 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work) { struct vhost_scsi_tmf *tmf = container_of(work, struct vhost_scsi_tmf, vwork); - struct vhost_virtqueue *ctl_vq, *vq; - int resp_code, i; - - if (tmf->scsi_resp == TMR_FUNCTION_COMPLETE) { - /* - * Flush IO vqs that don't share a worker with the ctl to make - * sure they have sent their responses before us. - */ - ctl_vq = &tmf->vhost->vqs[VHOST_SCSI_VQ_CTL].vq; - for (i = VHOST_SCSI_VQ_IO; i < tmf->vhost->dev.nvqs; i++) { - vq = &tmf->vhost->vqs[i].vq; - - if (vhost_vq_is_setup(vq) && - vq->worker != ctl_vq->worker) - vhost_vq_flush(vq); - } + int resp_code; + if (tmf->scsi_resp == TMR_FUNCTION_COMPLETE) resp_code = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED; - } else { + else resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED; - } vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs, tmf->vq_desc, &tmf->resp_iov, resp_code); vhost_scsi_release_tmf_res(tmf); } +static void vhost_scsi_tmf_flush_work(struct work_struct *work) +{ + struct vhost_scsi_tmf *tmf = container_of(work, struct vhost_scsi_tmf, + flush_work); + struct vhost_virtqueue *vq = &tmf->svq->vq; + /* + * Make sure we have sent responses for other commands before we + * send our response. + */ + vhost_dev_flush(vq->dev); + vhost_vq_work_queue(vq, &tmf->vwork); +} + static void vhost_scsi_handle_tmf(struct vhost_scsi *vs, struct vhost_scsi_tpg *tpg, struct vhost_virtqueue *vq, @@ -1337,6 +1335,7 @@ vhost_scsi_handle_tmf(struct vhost_scsi *vs, struct vhost_scsi_tpg *tpg, if (!tmf) goto send_reject; + INIT_WORK(&tmf->flush_work, vhost_scsi_tmf_flush_work); vhost_work_init(&tmf->vwork, vhost_scsi_tmf_resp_work); tmf->vhost = vs; tmf->svq = svq; -- 2.20.1