On 11/22/18 3:06 PM, w...@redhat.com wrote:
From: Wei Xu <w...@redhat.com>
tweaked vhost-net code to test migration.
@@ -1414,64 +1430,20 @@ long vhost_vring_ioctl(struct vhost_dev
r = -EFAULT;
break;
}
+ vq->last_avail_idx = s.num & 0x7FFF;
+ /* Forget the cached index value. */
+ vq->avail_idx = vq->last_avail_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ vq->last_avail_wrap_counter = !!(s.num & 0x8000);
+ vq->avail_wrap_counter = vq->last_avail_wrap_counter;
+
+ vq->last_used_idx = (s.num & 0x7fFF0000) >> 16;
+ vq->last_used_wrap_counter = !!(s.num & 0x80000000);
+ }
+ break;
+ case VHOST_GET_VRING_BASE:
+ s.index = idx;
+ s.num = vq->last_avail_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ s.num |= vq->last_avail_wrap_counter << 15;
+ s.num |= vq->last_used_idx << 16;
+ s.num |= vq->last_used_wrap_counter << 31;
+ }
+ if (copy_to_user(argp, &s, sizeof(s)))
+ r = -EFAULT;
+ break;
Signed-off-by: Wei Xu <w...@redhat.com>
---
hw/virtio/virtio.c | 35 ++++++++++++++++++++++++++++++-----
include/hw/virtio/virtio.h | 4 ++--
2 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 64d5c04..7487d3d 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2963,19 +2963,40 @@ hwaddr virtio_queue_get_used_size(VirtIODevice *vdev,
int n)
}
}
-uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
+int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
{
- return vdev->vq[n].last_avail_idx;
+ int idx;
+
+ if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
Also, I think you want to use virtio_vdev_has_feature() here instead,
else it will set wrap counter in the case ring_packed=on in the QEMU
command line but the feature has not been negotiated.
For example, with ring_packed=on and with stock Fedora 28 kernel, which
does not support packed ring, I get this warning with DPDK vhost user
backend:
VHOST_CONFIG: last_used_idx (32768) and vq->used->idx (0) mismatches;
some packets maybe resent for Tx and dropped for Rx
+ idx = vdev->vq[n].last_avail_idx;
+ idx |= ((int)vdev->vq[n].avail_wrap_counter) << 15;
+ idx |= (vdev->vq[n].used_idx) << 16;
+ idx |= ((int)vdev->vq[n].used_wrap_counter) << 31;
+ } else {
+ idx = (int)vdev->vq[n].last_avail_idx;
+ }
+ return idx;
}
-void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx)
+void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, int idx)
{
- vdev->vq[n].last_avail_idx = idx;
- vdev->vq[n].shadow_avail_idx = idx;
+ if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+ vdev->vq[n].last_avail_idx = idx & 0x7fff;
+ vdev->vq[n].avail_wrap_counter = !!(idx & 0x8000);
+ vdev->vq[n].used_idx = (idx & 0x7fff0000) >> 16;
+ vdev->vq[n].used_wrap_counter = !!(idx & 0x80000000);
+ } else {
+ vdev->vq[n].last_avail_idx = idx;
+ vdev->vq[n].shadow_avail_idx = idx;
+ }
}
void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n)
{
+ if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+ return;
+ }
+
rcu_read_lock();
if (vdev->vq[n].vring.desc) {
vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]);
@@ -2986,6 +3007,10 @@ void virtio_queue_restore_last_avail_idx(VirtIODevice
*vdev, int n)
void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)
{
+ if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+ return;
+ }
+
rcu_read_lock();
if (vdev->vq[n].vring.desc) {
vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 9c1fa07..a6fdf3f 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -272,8 +272,8 @@ hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int
n);
hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
-uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
-void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
+int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
+void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, int idx);
void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);