[PATCH v2 0/2] vhost: packed ring support completion

[PATCH v2 0/2] vhost: packed ring support completion

[Maxime Coquelin]

In this v2, the vring state num field structure is changed
to store both used and avail indexes and their wrap counters.

Initial series ading packed ring layout support to the
vhost library was missing the save and restore of the
wrap counters and indexs on vring base requests used for
migration.

First patch saves/restores the used and avail indexes and their
wrap counters values into/from the vring state num field.

Patch 2 advertise support for the packed ring.

Maxime Coquelin (2):
  vhost: add packed ring support to vring base requests
  vhost: advertize packed ring layout support

 lib/librte_vhost/vhost.h      |  3 ++-
 lib/librte_vhost/vhost_user.c | 41 ++++++++++++++++++++++++++++++-----
 2 files changed, 37 insertions(+), 7 deletions(-)

-- 
2.17.1

[PATCH v2 1/2] vhost: add packed ring support to vring base requests

[Maxime Coquelin]

For packed ring layout, we need save and restore avail and
used indexes, and their wrap counter values.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 41 ++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 508228a3c..c712c9a40 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -696,10 +696,24 @@ vhost_user_set_vring_base(struct virtio_net **pdev,
 			int main_fd __rte_unused)
 {
 	struct virtio_net *dev = *pdev;
-	dev->virtqueue[msg->payload.state.index]->last_used_idx  =
-			msg->payload.state.num;
-	dev->virtqueue[msg->payload.state.index]->last_avail_idx =
-			msg->payload.state.num;
+	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
+	uint64_t val = msg->payload.state.num;
+
+	if (vq_is_packed(dev)) {
+		/*
+		 * Bit[0:14]: avail index
+		 * Bit[15]: avail wrap counter
+		 * Bit[16:30]: used index
+		 * Bit[31]: used wrap counter
+		 */
+		vq->last_avail_idx = (val & 0x1f);
+		vq->avail_wrap_counter = (val & (0x1 << 15) >> 15);
+		vq->last_used_idx = (val & (0x1f << 16)) >> 16;
+		vq->used_wrap_counter = (val & (0x1 << 31) >> 31);
+	} else {
+		vq->last_used_idx = msg->payload.state.num;
+		vq->last_avail_idx = msg->payload.state.num;
+	}
 
 	return VH_RESULT_OK;
 }
@@ -1208,6 +1222,7 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
 {
 	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
+	uint64_t val;
 
 	/* We have to stop the queue (virtio) if it is running. */
 	vhost_destroy_device_notify(dev);
@@ -1215,8 +1230,22 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
 	dev->flags &= ~VIRTIO_DEV_READY;
 	dev->flags &= ~VIRTIO_DEV_VDPA_CONFIGURED;
 
-	/* Here we are safe to get the last avail index */
-	msg->payload.state.num = vq->last_avail_idx;
+	/* Here we are safe to get the indexes */
+	if (vq_is_packed(dev)) {
+		/*
+		 * Bit[0:14]: avail index
+		 * Bit[15]: avail wrap counter
+		 * Bit[16:30]: used index
+		 * Bit[31]: used wrap counter
+		 */
+		val = vq->last_avail_idx & 0x1f;
+		val |= vq->avail_wrap_counter << 15;
+		val |= (vq->last_used_idx & 0x1f) << 16;
+		val |= vq->used_wrap_counter << 31;
+		msg->payload.state.num = val;
+	} else {
+		msg->payload.state.num = vq->last_avail_idx;
+	}
 
 	RTE_LOG(INFO, VHOST_CONFIG,
 		"vring base idx:%d file:%d\n", msg->payload.state.index,
-- 
2.17.1

[PATCH v2 2/2] vhost: advertize packed ring layout support

[Maxime Coquelin]

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index b4abad30c..760f42192 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -275,7 +275,8 @@ struct vring_packed_desc_event {
 				(1ULL << VIRTIO_RING_F_EVENT_IDX) | \
 				(1ULL << VIRTIO_NET_F_MTU)  | \
 				(1ULL << VIRTIO_F_IN_ORDER) | \
-				(1ULL << VIRTIO_F_IOMMU_PLATFORM))
+				(1ULL << VIRTIO_F_IOMMU_PLATFORM) | \
+				(1ULL << VIRTIO_F_RING_PACKED))
 
 
 struct guest_page {
-- 
2.17.1

Re: [PATCH v2 0/2] vhost: packed ring support completion

[Maxime Coquelin]

Sorry, just notice I forgot to generate patches again after fixing patch
2, v3 coming soon.

On 10/18/2018 11:29 AM, Maxime Coquelin wrote:
> In this v2, the vring state num field structure is changed
> to store both used and avail indexes and their wrap counters.
> 
> Initial series ading packed ring layout support to the
> vhost library was missing the save and restore of the
> wrap counters and indexs on vring base requests used for
> migration.
> 
> First patch saves/restores the used and avail indexes and their
> wrap counters values into/from the vring state num field.
> 
> Patch 2 advertise support for the packed ring.
> 
> Maxime Coquelin (2):
>    vhost: add packed ring support to vring base requests
>    vhost: advertize packed ring layout support
> 
>   lib/librte_vhost/vhost.h      |  3 ++-
>   lib/librte_vhost/vhost_user.c | 41 ++++++++++++++++++++++++++++++-----
>   2 files changed, 37 insertions(+), 7 deletions(-)
>