patch 'net/virtio-user: fix used ring address calculation' has been queued to stable release 24.11.4

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/05/25. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/ea4cd024fda598469109db671eb09aa1796cf4c8

Thanks.

Kevin

---
>From ea4cd024fda598469109db671eb09aa1796cf4c8 Mon Sep 17 00:00:00 2001
From: Maxime Coquelin <maxime.coquelin at redhat.com>
Date: Tue, 7 Oct 2025 16:47:54 +0200
Subject: [PATCH] net/virtio-user: fix used ring address calculation

[ upstream commit 7aa71d336c18bac0c942018819043a5420a5b160 ]

This patch fixes the used ring address calculation, to
avoid Vhost-vDPA backends (such as VDUSE) to fail while
trying to translate it.

Fixes: 666ef294ddf7 ("net/virtio-user: share descriptor IOVA to backend")

Reported-by: Adrian Moreno <amorenoz at redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Acked-by: David Marchand <david.marchand at redhat.com>
---
 .../net/virtio/virtio_user/virtio_user_dev.c  | 30 ++++++++-----------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 2997d2bd26..2642ecf893 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -119,5 +119,5 @@ virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 	struct vring *vring = &dev->vrings.split[queue_sel];
 	struct vring_packed *pq_vring = &dev->vrings.packed[queue_sel];
-	uint64_t desc_addr, avail_addr, used_addr;
+	uint64_t desc_addr, desc_iova_addr, avail_addr, used_addr;
 	struct vhost_vring_addr addr = {
 		.index = queue_sel,
@@ -139,23 +139,19 @@ virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
 
 	if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
-		desc_addr = pq_vring->desc_iova;
-		avail_addr = desc_addr + pq_vring->num * sizeof(struct vring_packed_desc);
-		used_addr =  RTE_ALIGN_CEIL(avail_addr + sizeof(struct vring_packed_desc_event),
-					    VIRTIO_VRING_ALIGN);
-
-		addr.desc_user_addr = desc_addr;
-		addr.avail_user_addr = avail_addr;
-		addr.used_user_addr = used_addr;
+		desc_iova_addr = pq_vring->desc_iova;
+		desc_addr = (uint64_t)(uintptr_t)pq_vring->desc;
+		avail_addr = (uint64_t)(uintptr_t)pq_vring->driver;
+		used_addr = (uint64_t)(uintptr_t)pq_vring->device;
 	} else {
-		desc_addr = vring->desc_iova;
-		avail_addr = desc_addr + vring->num * sizeof(struct vring_desc);
-		used_addr = RTE_ALIGN_CEIL((uintptr_t)(&vring->avail->ring[vring->num]),
-					   VIRTIO_VRING_ALIGN);
-
-		addr.desc_user_addr = desc_addr;
-		addr.avail_user_addr = avail_addr;
-		addr.used_user_addr = used_addr;
+		desc_iova_addr = vring->desc_iova;
+		desc_addr = (uint64_t)(uintptr_t)vring->desc;
+		avail_addr = (uint64_t)(uintptr_t)vring->avail;
+		used_addr = (uint64_t)(uintptr_t)vring->used;
 	}
 
+	addr.desc_user_addr = desc_iova_addr;
+	addr.avail_user_addr = (desc_iova_addr - desc_addr) + avail_addr;
+	addr.used_user_addr = (desc_iova_addr - desc_addr) + used_addr;
+
 	state.index = queue_sel;
 	state.num = vring->num;
-- 
2.51.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-10-31 13:53:54.517566209 +0000
+++ 0075-net-virtio-user-fix-used-ring-address-calculation.patch	2025-10-31 13:53:52.176523805 +0000
@@ -1 +1 @@
-From 7aa71d336c18bac0c942018819043a5420a5b160 Mon Sep 17 00:00:00 2001
+From ea4cd024fda598469109db671eb09aa1796cf4c8 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 7aa71d336c18bac0c942018819043a5420a5b160 ]
+
@@ -11 +12,0 @@
-Cc: stable at dpdk.org
@@ -21 +22 @@
-index 187f81b066..f3df73c1f0 100644
+index 2997d2bd26..2642ecf893 100644