Commit d555e546 authored by Darek Stojaczyk's avatar Darek Stojaczyk Committed by Jim Harris
Browse files

vhost: setup iovs even for empty descriptors 



This ensures that SPDK will detect descriptor chains
that are too long.

The additional check in vhost block stands as an
optimization and makes us fail the corrupted I/O early.

Change-Id: Icceaa0dd938dca96a1872e5ee96bf6a151fdd9e7
Signed-off-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Signed-off-by: default avatarDima Stepanov <dstepanov.src@gmail.com>
Reviewed-on: https://review.gerrithub.io/c/433641


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 174613bf

lib/vhost/vhost.c

+2 −2
Original line number Diff line number Diff line
@@ -468,7 +468,7 @@ spdk_vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec * 
	uintptr_t payload = desc->addr;

	uintptr_t vva;



	while (remaining) {

	do {

		if (*iov_index >= SPDK_VHOST_IOVS_MAX) {

			SPDK_ERRLOG("SPDK_VHOST_IOVS_MAX(%d) reached\n", SPDK_VHOST_IOVS_MAX);

			return -1;
@@ -503,7 +503,7 @@ spdk_vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec * 
		remaining -= len;

		payload += len;

		(*iov_index)++;

	}

	} while (remaining);



	return 0;

}

lib/vhost/vhost_blk.c

+10 −0
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ blk_iovs_setup(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtq 
	struct vring_desc *desc, *desc_table;

	uint16_t out_cnt = 0, cnt = 0;

	uint32_t desc_table_size, len = 0;

	uint32_t desc_handled_cnt;

	int rc;



	rc = spdk_vhost_vq_get_desc(vsession, vq, req_idx, &desc, &desc_table, &desc_table_size);
@@ -134,6 +135,7 @@ blk_iovs_setup(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtq 
		return -1;

	}



	desc_handled_cnt = 0;

	while (1) {

		/*

		 * Maximum cnt reached?
@@ -163,6 +165,14 @@ blk_iovs_setup(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtq 
		} else if (desc == NULL) {

			break;

		}



		desc_handled_cnt++;

		if (spdk_unlikely(desc_handled_cnt > desc_table_size)) {

			/* Break a cycle and report an error, if any. */

			SPDK_ERRLOG("%s: found a cycle in the descriptor chain: desc_table_size = %d, desc_handled_cnt = %d.\n",

				    vdev->name, desc_table_size, desc_handled_cnt);

			return -1;

		}

	}



	/*