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Commit 95e7c434 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

vhost/scsi: Enable T10 PI IOV -> SGL memory mapping 



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: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent e31885dd

drivers/vhost/scsi.c

+124 −59
Original line number Diff line number Diff line
@@ -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
@@ -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;
@@ -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;

}
@@ -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;

	}
@@ -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);
@@ -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);

	/*
@@ -1033,29 +1040,38 @@ 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)) {
@@ -1063,17 +1079,78 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) 
			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);
@@ -1081,40 +1158,28 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) 
		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
@@ -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);