[RFC PATCH 19/24] vdpa_sim: use separated iov for reading and writing

Jason Wang
2020-09-24T03:21:20Z

In order to support control virtqueue whose commands have both in and
out descriptors, we need to use separated iov for reading and writing
in vdpa_sim.

Signed-off-by: Jason Wang <jasowang at redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 5dc04ec271bb..d1764a64578d 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -40,7 +40,8 @@ MODULE_PARM_DESC(batch_mapping, "Batched mapping 1
-Enable; 0 - Disable");

 struct vdpasim_virtqueue {
 	struct vringh vring;
-	struct vringh_kiov iov;
+	struct vringh_kiov riov;
+	struct vringh_kiov wiov;
 	unsigned short head;
 	bool ready;
 	u64 desc_addr;
@@ -173,12 +174,12 @@ static void vdpasim_work(struct work_struct *work)

 	while (true) {
 		total_write = 0;
-		err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL,
+		err = vringh_getdesc_iotlb(&txq->vring, &txq->riov, NULL,
 					   &txq->head, GFP_ATOMIC);
 		if (err <= 0)
 			break;

-		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov,
+		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->wiov,
 					   &rxq->head, GFP_ATOMIC);
 		if (err <= 0) {
 			vringh_complete_iotlb(&txq->vring, txq->head, 0);
@@ -186,13 +187,13 @@ static void vdpasim_work(struct work_struct *work)
 		}

 		while (true) {
-			read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
+			read = vringh_iov_pull_iotlb(&txq->vring, &txq->riov,
 						     vdpasim->buffer,
 						     PAGE_SIZE);
 			if (read <= 0)
 				break;

-			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov,
+			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->wiov,
 						      vdpasim->buffer, read);
 			if (write <= 0)
 				break;
--
2.20.1