在 2023/1/19 17:14, Eugenio Perez Martin 写道:
On Thu, Jan 19, 2023 at 4:16 AM Jason Wang <jasowang@xxxxxxxxxx> wrote:
On Thu, Jan 19, 2023 at 12:44 AM Eugenio Pérez <eperezma@xxxxxxxxxx> wrote:
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>
---
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 cb88891b44a8..8839232a3fcb 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;
Does this need to be serialized with the datapath?
E.g in set_vq_state() we do:
spin_lock(&vdpasim->lock);
vrh->last_avail_idx = state->split.avail_index;
spin_unlock(&vdpasim->lock);
vdpasim_queue_ready is called from vdpasim_set_vq_ready, which holds
these locks.
Maybe it's too much indirection and to embed vdpasim_queue_ready in
vdpasim_set_vq_ready would be clearer for the future?
Nope, I miss the caller.
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
Thanks!
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