Re: [PATCH 1/2] vdpa_sim: not reset state in vdpasim_queue_ready
From: Jason Wang <hidden>
Date: 2023-01-19 05:23:59
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On Thu, Jan 19, 2023 at 12:44 AM Eugenio Pérez [off-list ref] wrote:
quoted hunk
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@redhat.com> --- 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); Thanks
vq->vring.notify = vdpasim_vq_notify; } -- 2.31.1
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