[PATCH 17/21] vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov

[Jason Wang]

From: Stefano Garzarella <sgarz...@redhat.com>

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 <jasow...@redhat.com>
Signed-off-by: Stefano Garzarella <sgarz...@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 140de45ffff2..fe4888dfb70f 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -44,7 +44,8 @@ MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
 
 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;
@@ -178,12 +179,12 @@ 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->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);
@@ -191,13 +192,13 @@ 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->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;
-- 
2.25.1