From a8bdd24bc2b882fd593a7ab012ecbb0ae04790be Mon Sep 17 00:00:00 2001
From: Jin Yu <jin.yu@intel.com>
Date: Tue, 25 Feb 2020 18:54:11 +0800
Subject: [PATCH] vhost: split desc_to_iovs function

Use the payload to construct iovs so that split desc
or packed desc can both work.

Change-Id: Ib2c60b6eb53d0d615594e97b3d3ae1a365908b6c
Signed-off-by: Jin Yu <jin.yu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/1000
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
---
 lib/vhost/vhost.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index f55bc0538..89f6c4504 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -468,14 +468,12 @@ vhost_vring_desc_is_wr(struct vring_desc *cur_desc)
 	return !!(cur_desc->flags & VRING_DESC_F_WRITE);
 }
 
-int
-vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
-			uint16_t *iov_index, const struct vring_desc *desc)
+static int
+vhost_vring_desc_payload_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
+				uint16_t *iov_index, uintptr_t payload, uint64_t remaining)
 {
-	uint64_t len;
-	uint64_t remaining = desc->len;
-	uintptr_t payload = desc->addr;
 	uintptr_t vva;
+	uint64_t len;
 
 	do {
 		if (*iov_index >= SPDK_VHOST_IOVS_MAX) {
@@ -498,6 +496,14 @@ vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
 	return 0;
 }
 
+int
+vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
+			uint16_t *iov_index, const struct vring_desc *desc)
+{
+	return vhost_vring_desc_payload_to_iov(vsession, iov, iov_index,
+					       desc->addr, desc->len);
+}
+
 static struct spdk_vhost_session *
 vhost_session_find_by_id(struct spdk_vhost_dev *vdev, unsigned id)
 {