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[RFCv2,7/7] virtio-scsi: Enable DIF/DIX modes in SCSI host LLD

Message ID 1395034381-656-8-git-send-email-nab@daterainc.com (mailing list archive)
State New, archived
Headers show

Commit Message

Nicholas A. Bellinger March 17, 2014, 5:33 a.m. UTC 
From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch updates virtscsi_probe() to setup necessary Scsi_Host
level protection resources. (currently hardcoded to 1)

It changes virtscsi_add_cmd() to attach outgoing / incoming
protection SGLs preceeding the data payload, and is using the
new virtio_scsi_cmd_req_pi->d[oi],pi_niv field to signal
to signal to vhost/scsi how many prot_sgs to expect.

v2 changes:
  - Make protection buffer come before data buffer (Paolo)
  - Enable virtio_scsi_cmd_req_pi usage (Paolo)

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@dev.mellanox.co.il>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/scsi/virtio_scsi.c |   79 ++++++++++++++++++++++++++++++++++----------
 1 files changed, 61 insertions(+), 18 deletions(-)
diff mbox

Patch

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 16bfd50..4cccfed 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -37,6 +37,7 @@  struct virtio_scsi_cmd {
 	struct completion *comp;
 	union {
 		struct virtio_scsi_cmd_req       cmd;
+		struct virtio_scsi_cmd_req_pi    cmd_pi;
 		struct virtio_scsi_ctrl_tmf_req  tmf;
 		struct virtio_scsi_ctrl_an_req   an;
 	} req;
@@ -440,7 +441,7 @@  static int virtscsi_add_cmd(struct virtqueue *vq,
 			    size_t req_size, size_t resp_size, gfp_t gfp)
 {
 	struct scsi_cmnd *sc = cmd->sc;
-	struct scatterlist *sgs[4], req, resp;
+	struct scatterlist *sgs[6], req, resp;
 	struct sg_table *out, *in;
 	unsigned out_num = 0, in_num = 0;
 
@@ -458,16 +459,24 @@  static int virtscsi_add_cmd(struct virtqueue *vq,
 	sgs[out_num++] = &req;
 
 	/* Data-out buffer.  */
-	if (out)
+	if (out) {
+		/* Place WRITE protection SGLs before Data OUT payload */
+		if (scsi_prot_sg_count(sc))
+			sgs[out_num++] = scsi_prot_sglist(sc);
 		sgs[out_num++] = out->sgl;
+	}
 
 	/* Response header.  */
 	sg_init_one(&resp, &cmd->resp, resp_size);
 	sgs[out_num + in_num++] = &resp;
 
 	/* Data-in buffer */
-	if (in)
+	if (in) {
+		/* Place READ protection SGLs before Data IN payload */
+		if (scsi_prot_sg_count(sc))
+			sgs[out_num + in_num++] = scsi_prot_sglist(sc);
 		sgs[out_num + in_num++] = in->sgl;
+	}
 
 	return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
 }
@@ -492,12 +501,36 @@  static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
 	return err;
 }
 
+static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req *cmd,
+				 struct scsi_cmnd *sc)
+{
+	cmd->lun[0] = 1;
+	cmd->lun[1] = sc->device->id;
+	cmd->lun[2] = (sc->device->lun >> 8) | 0x40;
+	cmd->lun[3] = sc->device->lun & 0xff;
+	cmd->tag = (unsigned long)sc;
+	cmd->task_attr = VIRTIO_SCSI_S_SIMPLE;
+	cmd->prio = 0;
+	cmd->crn = 0;
+}
+
+static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi,
+				    struct scsi_cmnd *sc)
+{
+	virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc);
+
+	if (sc->sc_data_direction == DMA_TO_DEVICE)
+		cmd_pi->do_pi_niov = scsi_prot_sg_count(sc);
+	else if (sc->sc_data_direction == DMA_FROM_DEVICE)
+		cmd_pi->di_pi_niov = scsi_prot_sg_count(sc);
+}
+
 static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
 				 struct virtio_scsi_vq *req_vq,
 				 struct scsi_cmnd *sc)
 {
 	struct virtio_scsi_cmd *cmd;
-	int ret;
+	int ret, req_size;
 
 	struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
 	BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
@@ -515,22 +548,20 @@  static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
 
 	memset(cmd, 0, sizeof(*cmd));
 	cmd->sc = sc;
-	cmd->req.cmd = (struct virtio_scsi_cmd_req){
-		.lun[0] = 1,
-		.lun[1] = sc->device->id,
-		.lun[2] = (sc->device->lun >> 8) | 0x40,
-		.lun[3] = sc->device->lun & 0xff,
-		.tag = (unsigned long)sc,
-		.task_attr = VIRTIO_SCSI_S_SIMPLE,
-		.prio = 0,
-		.crn = 0,
-	};
 
 	BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
-	memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
 
-	if (virtscsi_kick_cmd(req_vq, cmd,
-			      sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
+	if (scsi_prot_sg_count(sc)) {
+		virtio_scsi_init_hdr_pi(&cmd->req.cmd_pi, sc);
+		memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len);
+		req_size = sizeof(cmd->req.cmd_pi);
+	} else {
+		virtio_scsi_init_hdr(&cmd->req.cmd, sc);
+		memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
+		req_size = sizeof(cmd->req.cmd);
+	}
+
+	if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd),
 			      GFP_ATOMIC) == 0)
 		ret = 0;
 	else
@@ -871,7 +902,7 @@  static int virtscsi_probe(struct virtio_device *vdev)
 {
 	struct Scsi_Host *shost;
 	struct virtio_scsi *vscsi;
-	int err;
+	int err, host_prot;
 	u32 sg_elems, num_targets;
 	u32 cmd_per_lun;
 	u32 num_queues;
@@ -921,6 +952,17 @@  static int virtscsi_probe(struct virtio_device *vdev)
 	shost->max_id = num_targets;
 	shost->max_channel = 0;
 	shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
+
+	/* FIXME: Figure out why this is broken.. */
+	if (1 || virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
+		host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
+			    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
+			    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;
+
+		scsi_host_set_prot(shost, host_prot);
+		scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
+	}
+
 	err = scsi_add_host(shost, &vdev->dev);
 	if (err)
 		goto scsi_add_host_failed;
@@ -990,6 +1032,7 @@  static struct virtio_device_id id_table[] = {
 static unsigned int features[] = {
 	VIRTIO_SCSI_F_HOTPLUG,
 	VIRTIO_SCSI_F_CHANGE,
+	VIRTIO_SCSI_F_T10_PI,
 };
 
 static struct virtio_driver virtio_scsi_driver = {