Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3aee26b4 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

vhost/scsi: Add pre-allocation for tv_cmd SGL + upages memory 



This patch adds support for pre-allocation of per tv_cmd descriptor
scatterlist + user-space page pointer memory using se_sess->sess_cmd_map
within tcm_vhost_make_nexus() code.

This includes sanity checks within vhost_scsi_map_to_sgl()
to reject I/O that exceeds these initial hardcoded values, and
the necessary cleanup in tcm_vhost_make_nexus() failure path +
tcm_vhost_drop_nexus().

v3 changes:
  - Rebase to v3.11-rc5 code

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Reviewed-by: default avatarAsias He <asias@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 4824d3bf

drivers/vhost/scsi.c

+80 −19
Original line number Original line Diff line number Diff line
@@ -56,6 +56,8 @@ 
#define TCM_VHOST_NAMELEN 256

#define TCM_VHOST_NAMELEN 256

#define TCM_VHOST_MAX_CDB_SIZE 32

#define TCM_VHOST_MAX_CDB_SIZE 32

#define TCM_VHOST_DEFAULT_TAGS 256

#define TCM_VHOST_DEFAULT_TAGS 256

#define TCM_VHOST_PREALLOC_SGLS 2048

#define TCM_VHOST_PREALLOC_PAGES 2048





struct vhost_scsi_inflight {

struct vhost_scsi_inflight {

	/* Wait for the flush operation to finish */

	/* Wait for the flush operation to finish */
@@ -81,6 +83,7 @@ struct tcm_vhost_cmd { 
	u32 tvc_lun;

	u32 tvc_lun;

	/* Pointer to the SGL formatted memory from virtio-scsi */

	/* Pointer to the SGL formatted memory from virtio-scsi */

	struct scatterlist *tvc_sgl;

	struct scatterlist *tvc_sgl;

	struct page **tvc_upages;

	/* Pointer to response */

	/* Pointer to response */

	struct virtio_scsi_cmd_resp __user *tvc_resp;

	struct virtio_scsi_cmd_resp __user *tvc_resp;

	/* Pointer to vhost_scsi for our device */

	/* Pointer to vhost_scsi for our device */
@@ -458,8 +461,6 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd) 
		u32 i;

		u32 i;

		for (i = 0; i < tv_cmd->tvc_sgl_count; i++)

		for (i = 0; i < tv_cmd->tvc_sgl_count; i++)

			put_page(sg_page(&tv_cmd->tvc_sgl[i]));

			put_page(sg_page(&tv_cmd->tvc_sgl[i]));



		kfree(tv_cmd->tvc_sgl);

        }

        }





	tcm_vhost_put_inflight(tv_cmd->inflight);

	tcm_vhost_put_inflight(tv_cmd->inflight);
@@ -716,6 +717,8 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, 
	struct tcm_vhost_cmd *cmd;

	struct tcm_vhost_cmd *cmd;

	struct tcm_vhost_nexus *tv_nexus;

	struct tcm_vhost_nexus *tv_nexus;

	struct se_session *se_sess;

	struct se_session *se_sess;

	struct scatterlist *sg;

	struct page **pages;

	int tag;

	int tag;





	tv_nexus = tpg->tpg_nexus;

	tv_nexus = tpg->tpg_nexus;
@@ -727,8 +730,12 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, 




	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_KERNEL);

	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_KERNEL);

	cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[tag];

	cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[tag];

	sg = cmd->tvc_sgl;

	pages = cmd->tvc_upages;

	memset(cmd, 0, sizeof(struct tcm_vhost_cmd));

	memset(cmd, 0, sizeof(struct tcm_vhost_cmd));





	cmd->tvc_sgl = sg;

	cmd->tvc_upages = pages;

	cmd->tvc_se_cmd.map_tag = tag;

	cmd->tvc_se_cmd.map_tag = tag;

	cmd->tvc_tag = v_req->tag;

	cmd->tvc_tag = v_req->tag;

	cmd->tvc_task_attr = v_req->task_attr;

	cmd->tvc_task_attr = v_req->task_attr;
@@ -746,7 +753,8 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, 
 * Returns the number of scatterlist entries used or -errno on error.

 * Returns the number of scatterlist entries used or -errno on error.

 */

 */

static int

static int

vhost_scsi_map_to_sgl(struct scatterlist *sgl,

vhost_scsi_map_to_sgl(struct tcm_vhost_cmd *tv_cmd,

		      struct scatterlist *sgl,

		      unsigned int sgl_count,

		      unsigned int sgl_count,

		      struct iovec *iov,

		      struct iovec *iov,

		      int write)

		      int write)
@@ -758,13 +766,25 @@ vhost_scsi_map_to_sgl(struct scatterlist *sgl, 
	struct page **pages;

	struct page **pages;

	int ret, i;

	int ret, i;





	if (sgl_count > TCM_VHOST_PREALLOC_SGLS) {

		pr_err("vhost_scsi_map_to_sgl() psgl_count: %u greater than"

		       " preallocated TCM_VHOST_PREALLOC_SGLS: %u\n",

			sgl_count, TCM_VHOST_PREALLOC_SGLS);

		return -ENOBUFS;

	}



	pages_nr = iov_num_pages(iov);

	pages_nr = iov_num_pages(iov);

	if (pages_nr > sgl_count)

	if (pages_nr > sgl_count)

		return -ENOBUFS;

		return -ENOBUFS;





	pages = kmalloc(pages_nr * sizeof(struct page *), GFP_KERNEL);

	if (pages_nr > TCM_VHOST_PREALLOC_PAGES) {

	if (!pages)

		pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"

		return -ENOMEM;

		       " preallocated TCM_VHOST_PREALLOC_PAGES: %u\n",

			pages_nr, TCM_VHOST_PREALLOC_PAGES);

		return -ENOBUFS;

	}



	pages = tv_cmd->tvc_upages;





	ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);

	ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);

	/* No pages were pinned */

	/* No pages were pinned */
@@ -789,7 +809,6 @@ vhost_scsi_map_to_sgl(struct scatterlist *sgl, 
	}

	}





out:

out:

	kfree(pages);

	return ret;

	return ret;

}

}
@@ -813,24 +832,20 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd, 




	/* TODO overflow checking */

	/* TODO overflow checking */





	sg = kmalloc(sizeof(cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);

	sg = cmd->tvc_sgl;

	if (!sg)

	pr_debug("%s sg %p sgl_count %u\n", __func__, sg, sgl_count);

		return -ENOMEM;

	pr_debug("%s sg %p sgl_count %u is_err %d\n", __func__,

	       sg, sgl_count, !sg);

	sg_init_table(sg, sgl_count);

	sg_init_table(sg, sgl_count);





	cmd->tvc_sgl = sg;

	cmd->tvc_sgl_count = sgl_count;

	cmd->tvc_sgl_count = sgl_count;





	pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);

	pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);

	for (i = 0; i < niov; i++) {

	for (i = 0; i < niov; i++) {

		ret = vhost_scsi_map_to_sgl(sg, sgl_count, &iov[i], write);

		ret = vhost_scsi_map_to_sgl(cmd, sg, sgl_count, &iov[i],

					    write);

		if (ret < 0) {

		if (ret < 0) {

			for (i = 0; i < cmd->tvc_sgl_count; i++)

			for (i = 0; i < cmd->tvc_sgl_count; i++)

				put_page(sg_page(&cmd->tvc_sgl[i]));

				put_page(sg_page(&cmd->tvc_sgl[i]));

			kfree(cmd->tvc_sgl);



			cmd->tvc_sgl = NULL;

			cmd->tvc_sgl_count = 0;

			cmd->tvc_sgl_count = 0;

			return ret;

			return ret;

		}

		}
@@ -1660,11 +1675,31 @@ static void tcm_vhost_drop_nodeacl(struct se_node_acl *se_acl) 
	kfree(nacl);

	kfree(nacl);

}

}





static void tcm_vhost_free_cmd_map_res(struct tcm_vhost_nexus *nexus,

				       struct se_session *se_sess)

{

	struct tcm_vhost_cmd *tv_cmd;

	unsigned int i;



	if (!se_sess->sess_cmd_map)

		return;



	for (i = 0; i < TCM_VHOST_DEFAULT_TAGS; i++) {

		tv_cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[i];



		kfree(tv_cmd->tvc_sgl);

		kfree(tv_cmd->tvc_upages);

	}

}



static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,

static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,

				const char *name)

				const char *name)

{

{

	struct se_portal_group *se_tpg;

	struct se_portal_group *se_tpg;

	struct se_session *se_sess;

	struct tcm_vhost_nexus *tv_nexus;

	struct tcm_vhost_nexus *tv_nexus;

	struct tcm_vhost_cmd *tv_cmd;

	unsigned int i;





	mutex_lock(&tpg->tv_tpg_mutex);

	mutex_lock(&tpg->tv_tpg_mutex);

	if (tpg->tpg_nexus) {

	if (tpg->tpg_nexus) {
@@ -1692,6 +1727,26 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg, 
		kfree(tv_nexus);

		kfree(tv_nexus);

		return -ENOMEM;

		return -ENOMEM;

	}

	}

	se_sess = tv_nexus->tvn_se_sess;

	for (i = 0; i < TCM_VHOST_DEFAULT_TAGS; i++) {

		tv_cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[i];



		tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *

					TCM_VHOST_PREALLOC_SGLS, GFP_KERNEL);

		if (!tv_cmd->tvc_sgl) {

			mutex_unlock(&tpg->tv_tpg_mutex);

			pr_err("Unable to allocate tv_cmd->tvc_sgl\n");

			goto out;

		}



		tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *

					TCM_VHOST_PREALLOC_PAGES, GFP_KERNEL);

		if (!tv_cmd->tvc_upages) {

			mutex_unlock(&tpg->tv_tpg_mutex);

			pr_err("Unable to allocate tv_cmd->tvc_upages\n");

			goto out;

		}

	}

	/*

	/*

	 * Since we are running in 'demo mode' this call with generate a

	 * Since we are running in 'demo mode' this call with generate a

	 * struct se_node_acl for the tcm_vhost struct se_portal_group with

	 * struct se_node_acl for the tcm_vhost struct se_portal_group with
@@ -1703,9 +1758,7 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg, 
		mutex_unlock(&tpg->tv_tpg_mutex);

		mutex_unlock(&tpg->tv_tpg_mutex);

		pr_debug("core_tpg_check_initiator_node_acl() failed"

		pr_debug("core_tpg_check_initiator_node_acl() failed"

				" for %s\n", name);

				" for %s\n", name);

		transport_free_session(tv_nexus->tvn_se_sess);

		goto out;

		kfree(tv_nexus);

		return -ENOMEM;

	}

	}

	/*

	/*

	 * Now register the TCM vhost virtual I_T Nexus as active with the

	 * Now register the TCM vhost virtual I_T Nexus as active with the
@@ -1717,6 +1770,12 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg, 




	mutex_unlock(&tpg->tv_tpg_mutex);

	mutex_unlock(&tpg->tv_tpg_mutex);

	return 0;

	return 0;



out:

	tcm_vhost_free_cmd_map_res(tv_nexus, se_sess);

	transport_free_session(se_sess);

	kfree(tv_nexus);

	return -ENOMEM;

}

}





static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)

static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)
@@ -1756,6 +1815,8 @@ static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg) 
	pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"

	pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"

		" %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),

		" %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),

		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);

		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);



	tcm_vhost_free_cmd_map_res(tv_nexus, se_sess);

	/*

	/*

	 * Release the SCSI I_T Nexus to the emulated vhost Target Port

	 * Release the SCSI I_T Nexus to the emulated vhost Target Port

	 */

	 */