From: Eugenio Pérez <eperezma@xxxxxxxxxx>
[ Upstream commit 0e84f918fac8ae61dcb790534fad5e3555ca2930 ]
vdpasim_queue_ready calls vringh_init_iotlb, which resets split indexes.
But it can be called after setting a ring base with
vdpasim_set_vq_state.
Fix it by stashing them. They're still resetted in vdpasim_vq_reset.
This was discovered and tested live migrating the vdpa_sim_net device.
Fixes: 2c53d0f64c06 ("vdpasim: vDPA device simulator")
Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
Message-Id: <20230118164359.1523760-2-eperezma@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Tested-by: Lei Yang <leiyang@xxxxxxxxxx>
Stable-dep-of: b4cca6d48eb3 ("vdpa_sim: set last_used_idx as last_avail_idx in vdpasim_queue_ready")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index cb88891b44a8c..8839232a3fcbc 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -66,6 +66,7 @@ static void vdpasim_vq_notify(struct vringh *vring)
static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
{
struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+ uint16_t last_avail_idx = vq->vring.last_avail_idx;
vringh_init_iotlb(&vq->vring, vdpasim->features, vq->num, false,
(struct vring_desc *)(uintptr_t)vq->desc_addr,
@@ -74,6 +75,7 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
(struct vring_used *)
(uintptr_t)vq->device_addr);
+ vq->vring.last_avail_idx = last_avail_idx;
vq->vring.notify = vdpasim_vq_notify;
}
--
2.39.2
