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vhost/scsi: Enable T10 PI IOV -> SGL memory mapping
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This patch updates vhost_scsi_handle_vq() to check for the existance
of virtio_scsi_cmd_req_pi comparing vq->iov[0].iov_len in order to
calculate seperate data + protection SGLs from data_num.

Also update tcm_vhost_submission_work() to pass the pre-allocated
cmd->tvc_prot_sgl[] memory into target_submit_cmd_map_sgls(), and
update vhost_scsi_get_tag() parameters to accept scsi_tag, lun, and
task_attr.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@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>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Nicholas Bellinger committed Jun 2, 2014
1 parent e31885d commit 95e7c43
Showing 1 changed file with 124 additions and 59 deletions.
183 changes: 124 additions & 59 deletions drivers/vhost/scsi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -169,7 +169,8 @@ enum {
};

enum {
VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG)
VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
(1ULL << VIRTIO_SCSI_F_T10_PI)
};

#define VHOST_SCSI_MAX_TARGET 256
Expand Down Expand Up @@ -720,11 +721,9 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
}

static struct tcm_vhost_cmd *
vhost_scsi_get_tag(struct vhost_virtqueue *vq,
struct tcm_vhost_tpg *tpg,
struct virtio_scsi_cmd_req *v_req,
u32 exp_data_len,
int data_direction)
vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct tcm_vhost_tpg *tpg,
unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
u32 exp_data_len, int data_direction)
{
struct tcm_vhost_cmd *cmd;
struct tcm_vhost_nexus *tv_nexus;
Expand Down Expand Up @@ -756,13 +755,16 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq,
cmd->tvc_prot_sgl = prot_sg;
cmd->tvc_upages = pages;
cmd->tvc_se_cmd.map_tag = tag;
cmd->tvc_tag = v_req->tag;
cmd->tvc_task_attr = v_req->task_attr;
cmd->tvc_tag = scsi_tag;
cmd->tvc_lun = lun;
cmd->tvc_task_attr = task_attr;
cmd->tvc_exp_data_len = exp_data_len;
cmd->tvc_data_direction = data_direction;
cmd->tvc_nexus = tv_nexus;
cmd->inflight = tcm_vhost_get_inflight(vq);

memcpy(cmd->tvc_cdb, cdb, TCM_VHOST_MAX_CDB_SIZE);

return cmd;
}

Expand Down Expand Up @@ -913,18 +915,17 @@ static void tcm_vhost_submission_work(struct work_struct *work)
container_of(work, struct tcm_vhost_cmd, work);
struct tcm_vhost_nexus *tv_nexus;
struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
struct scatterlist *sg_ptr, *sg_bidi_ptr = NULL;
int rc, sg_no_bidi = 0;
struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
int rc;

/* FIXME: BIDI operation */
if (cmd->tvc_sgl_count) {
sg_ptr = cmd->tvc_sgl;
/* FIXME: Fix BIDI operation in tcm_vhost_submission_work() */
#if 0
if (se_cmd->se_cmd_flags & SCF_BIDI) {
sg_bidi_ptr = NULL;
sg_no_bidi = 0;
}
#endif

if (cmd->tvc_prot_sgl_count)
sg_prot_ptr = cmd->tvc_prot_sgl;
else
se_cmd->prot_pto = true;
} else {
sg_ptr = NULL;
}
Expand All @@ -935,7 +936,7 @@ static void tcm_vhost_submission_work(struct work_struct *work)
cmd->tvc_lun, cmd->tvc_exp_data_len,
cmd->tvc_task_attr, cmd->tvc_data_direction,
TARGET_SCF_ACK_KREF, sg_ptr, cmd->tvc_sgl_count,
sg_bidi_ptr, sg_no_bidi, NULL, 0);
NULL, 0, sg_prot_ptr, cmd->tvc_prot_sgl_count);
if (rc < 0) {
transport_send_check_condition_and_sense(se_cmd,
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
Expand Down Expand Up @@ -967,12 +968,18 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
{
struct tcm_vhost_tpg **vs_tpg;
struct virtio_scsi_cmd_req v_req;
struct virtio_scsi_cmd_req_pi v_req_pi;
struct tcm_vhost_tpg *tpg;
struct tcm_vhost_cmd *cmd;
u32 exp_data_len, data_first, data_num, data_direction;
u64 tag;
u32 exp_data_len, data_first, data_num, data_direction, prot_first;
unsigned out, in, i;
int head, ret;
u8 target;
int head, ret, data_niov, prot_niov, prot_bytes;
size_t req_size;
u16 lun;
u8 *target, *lunp, task_attr;
bool hdr_pi;
void *req, *cdb;

mutex_lock(&vq->mutex);
/*
Expand Down Expand Up @@ -1003,7 +1010,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
break;
}

/* FIXME: BIDI operation */
/* FIXME: BIDI operation */
if (out == 1 && in == 1) {
data_direction = DMA_NONE;
data_first = 0;
Expand Down Expand Up @@ -1033,88 +1040,146 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
break;
}

if (unlikely(vq->iov[0].iov_len != sizeof(v_req))) {
vq_err(vq, "Expecting virtio_scsi_cmd_req, got %zu"
" bytes\n", vq->iov[0].iov_len);
if (vs->dev.acked_features & VIRTIO_SCSI_F_T10_PI) {
req = &v_req_pi;
lunp = &v_req_pi.lun[0];
target = &v_req_pi.lun[1];
req_size = sizeof(v_req_pi);
hdr_pi = true;
} else {
req = &v_req;
lunp = &v_req.lun[0];
target = &v_req.lun[1];
req_size = sizeof(v_req);
hdr_pi = false;
}

if (unlikely(vq->iov[0].iov_len < req_size)) {
pr_err("Expecting virtio-scsi header: %zu, got %zu\n",
req_size, vq->iov[0].iov_len);
break;
}
pr_debug("Calling __copy_from_user: vq->iov[0].iov_base: %p,"
" len: %zu\n", vq->iov[0].iov_base, sizeof(v_req));
ret = __copy_from_user(&v_req, vq->iov[0].iov_base,
sizeof(v_req));
ret = memcpy_fromiovecend(req, &vq->iov[0], 0, req_size);
if (unlikely(ret)) {
vq_err(vq, "Faulted on virtio_scsi_cmd_req\n");
break;
}

/* virtio-scsi spec requires byte 0 of the lun to be 1 */
if (unlikely(v_req.lun[0] != 1)) {
if (unlikely(*lunp != 1)) {
vhost_scsi_send_bad_target(vs, vq, head, out);
continue;
}

/* Extract the tpgt */
target = v_req.lun[1];
tpg = ACCESS_ONCE(vs_tpg[target]);
tpg = ACCESS_ONCE(vs_tpg[*target]);

/* Target does not exist, fail the request */
if (unlikely(!tpg)) {
vhost_scsi_send_bad_target(vs, vq, head, out);
continue;
}

data_niov = data_num;
prot_niov = prot_first = prot_bytes = 0;
/*
* Determine if any protection information iovecs are preceeding
* the actual data payload, and adjust data_first + data_niov
* values accordingly for vhost_scsi_map_iov_to_sgl() below.
*
* Also extract virtio_scsi header bits for vhost_scsi_get_tag()
*/
if (hdr_pi) {
if (v_req_pi.pi_bytesout) {
if (data_direction != DMA_TO_DEVICE) {
vq_err(vq, "Received non zero do_pi_niov"
", but wrong data_direction\n");
goto err_cmd;
}
prot_bytes = v_req_pi.pi_bytesout;
} else if (v_req_pi.pi_bytesin) {
if (data_direction != DMA_FROM_DEVICE) {
vq_err(vq, "Received non zero di_pi_niov"
", but wrong data_direction\n");
goto err_cmd;
}
prot_bytes = v_req_pi.pi_bytesin;
}
if (prot_bytes) {
int tmp = 0;

for (i = 0; i < data_num; i++) {
tmp += vq->iov[data_first + i].iov_len;
prot_niov++;
if (tmp >= prot_bytes)
break;
}
prot_first = data_first;
data_first += prot_niov;
data_niov = data_num - prot_niov;
}
tag = v_req_pi.tag;
task_attr = v_req_pi.task_attr;
cdb = &v_req_pi.cdb[0];
lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
} else {
tag = v_req.tag;
task_attr = v_req.task_attr;
cdb = &v_req.cdb[0];
lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
}
exp_data_len = 0;
for (i = 0; i < data_num; i++)
for (i = 0; i < data_niov; i++)
exp_data_len += vq->iov[data_first + i].iov_len;
/*
* Check that the recieved CDB size does not exceeded our
* hardcoded max for vhost-scsi
*
* TODO what if cdb was too small for varlen cdb header?
*/
if (unlikely(scsi_command_size(cdb) > TCM_VHOST_MAX_CDB_SIZE)) {
vq_err(vq, "Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cdb), TCM_VHOST_MAX_CDB_SIZE);
goto err_cmd;
}

cmd = vhost_scsi_get_tag(vq, tpg, &v_req,
cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
exp_data_len, data_direction);
if (IS_ERR(cmd)) {
vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
PTR_ERR(cmd));
goto err_cmd;
}

pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
": %d\n", cmd, exp_data_len, data_direction);

cmd->tvc_vhost = vs;
cmd->tvc_vq = vq;
cmd->tvc_resp = vq->iov[out].iov_base;

/*
* Copy in the recieved CDB descriptor into cmd->tvc_cdb
* that will be used by tcm_vhost_new_cmd_map() and down into
* target_setup_cmd_from_cdb()
*/
memcpy(cmd->tvc_cdb, v_req.cdb, TCM_VHOST_MAX_CDB_SIZE);
/*
* Check that the recieved CDB size does not exceeded our
* hardcoded max for tcm_vhost
*/
/* TODO what if cdb was too small for varlen cdb header? */
if (unlikely(scsi_command_size(cmd->tvc_cdb) >
TCM_VHOST_MAX_CDB_SIZE)) {
vq_err(vq, "Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cmd->tvc_cdb),
TCM_VHOST_MAX_CDB_SIZE);
goto err_free;
}
cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;

pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
cmd->tvc_cdb[0], cmd->tvc_lun);

if (prot_niov) {
ret = vhost_scsi_map_iov_to_prot(cmd,
&vq->iov[prot_first], prot_niov,
data_direction == DMA_FROM_DEVICE);
if (unlikely(ret)) {
vq_err(vq, "Failed to map iov to"
" prot_sgl\n");
goto err_free;
}
}
if (data_direction != DMA_NONE) {
ret = vhost_scsi_map_iov_to_sgl(cmd,
&vq->iov[data_first], data_num,
&vq->iov[data_first], data_niov,
data_direction == DMA_FROM_DEVICE);
if (unlikely(ret)) {
vq_err(vq, "Failed to map iov to sgl\n");
goto err_free;
}
}

/*
* Save the descriptor from vhost_get_vq_desc() to be used to
* complete the virtio-scsi request in TCM callback context via
Expand Down Expand Up @@ -1788,7 +1853,7 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
tv_nexus->tvn_se_sess = transport_init_session_tags(
TCM_VHOST_DEFAULT_TAGS,
sizeof(struct tcm_vhost_cmd),
TARGET_PROT_NORMAL);
TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
if (IS_ERR(tv_nexus->tvn_se_sess)) {
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(tv_nexus);
Expand Down

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