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virtio-scsi: Enable DIF/DIX modes in SCSI host LLD
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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->pi_bytes[out,in] field to signal
to signal to vhost/scsi bytes to expect for protection data.

(Add missing #include <linux/blkdev.h> for blk_integrity - sfr + nab)

Acked-by: 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>
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Nicholas Bellinger committed Jun 2, 2014
1 parent 95e7c43 commit e6dc783
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Showing 2 changed files with 70 additions and 18 deletions.
1 change: 1 addition & 0 deletions drivers/scsi/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -1773,6 +1773,7 @@ config SCSI_BFA_FC
config SCSI_VIRTIO
tristate "virtio-scsi support"
depends on VIRTIO
select BLK_DEV_INTEGRITY
help
This is the virtual HBA driver for virtio. If the kernel will
be used in a virtual machine, say Y or M.
Expand Down
87 changes: 69 additions & 18 deletions drivers/scsi/virtio_scsi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
#include <linux/virtio_config.h>
#include <linux/virtio_scsi.h>
#include <linux/cpu.h>
#include <linux/blkdev.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
Expand All @@ -37,6 +38,7 @@ 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;
Expand Down Expand Up @@ -440,7 +442,7 @@ 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;

Expand All @@ -458,16 +460,24 @@ 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);
}
Expand All @@ -492,12 +502,44 @@ 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)
{
struct request *rq = sc->request;
struct blk_integrity *bi;

virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc);

if (!rq || !scsi_prot_sg_count(sc))
return;

bi = blk_get_integrity(rq->rq_disk);

if (sc->sc_data_direction == DMA_TO_DEVICE)
cmd_pi->pi_bytesout = blk_rq_sectors(rq) * bi->tuple_size;
else if (sc->sc_data_direction == DMA_FROM_DEVICE)
cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size;
}

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);
Expand All @@ -515,22 +557,20 @@ 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 (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) {
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
Expand Down Expand Up @@ -871,7 +911,7 @@ 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;
Expand Down Expand Up @@ -921,6 +961,16 @@ 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;

if (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;
Expand Down Expand Up @@ -990,6 +1040,7 @@ 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 = {
Expand Down

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