[PATCH v4 17/18] vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov

From: Stefano Garzarella
Date: Tue Dec 15 2020 - 09:48:31 EST


vringh_getdesc_iotlb() manages 2 iovs for writable and readable
descriptors. This is very useful for the block device, where for
each request we have both types of descriptor.

Let's split the vdpasim_virtqueue's iov field in out_iov and
in_iov to use them with vringh_getdesc_iotlb().

We are using VIRTIO terminology for "out" (readable by the device)
and "in" (writable by the device) descriptors.

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
v2:
- used VIRTIO terminology [Stefan]
---
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 60e45db29b15..875e42390a13 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -44,7 +44,8 @@ u8 macaddr_buf[ETH_ALEN];

struct vdpasim_virtqueue {
struct vringh vring;
- struct vringh_kiov iov;
+ struct vringh_kiov in_iov;
+ struct vringh_kiov out_iov;
unsigned short head;
bool ready;
u64 desc_addr;
@@ -210,12 +211,12 @@ static void vdpasim_net_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->out_iov, 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->in_iov,
&rxq->head, GFP_ATOMIC);
if (err <= 0) {
vringh_complete_iotlb(&txq->vring, txq->head, 0);
@@ -223,13 +224,13 @@ static void vdpasim_net_work(struct work_struct *work)
}

while (true) {
- read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
+ read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
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->in_iov,
vdpasim->buffer, read);
if (write <= 0)
break;
--
2.26.2