qemu-kvm/kvm-vdpa-move-vhost_vdpa_set_vring_ready-to-the-caller.patch

From 09bf0febef2512f00e71edca0fcbaf452652c2c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
Date: Thu, 10 Aug 2023 11:27:28 +0200
Subject: [PATCH 6/7] vdpa: move vhost_vdpa_set_vring_ready to the caller
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RH-Author: Eugenio Pérez <eperezma@redhat.com>
RH-MergeRequest: 199: CVQ migration support
RH-Jira: RHEL-923
RH-Acked-by: Jason Wang <jasowang@redhat.com>
RH-Acked-by: Cindy Lu <lulu@redhat.com>
RH-Commit: [6/7] cf4fd1071ca127914c8e8d6aefec451cad97ecc1 (eperezmartin/qemu-kvm)

Doing that way allows CVQ to be enabled before the dataplane vqs,
restoring the state as MQ or MAC addresses properly in the case of a
migration.

The patch does it by defining a ->load NetClientInfo callback also for
dataplane.  Ideally, this should be done by an independent patch, but
the function is already static so it would only add an empty
vhost_vdpa_net_data_load stub.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
v3:
* Fix subject typo
* Expand patch message so it explains why
---
 hw/virtio/vdpa-dev.c   |  3 +++
 hw/virtio/vhost-vdpa.c |  3 ---
 net/vhost-vdpa.c       | 41 +++++++++++++++++++++++++++++++----------
 3 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 01b41eb0f1..8c47d643bf 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -256,6 +256,9 @@ static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp)
         error_setg_errno(errp, -ret, "Error starting vhost");
         goto err_guest_notifiers;
     }
+    for (i = 0; i < s->dev.nvqs; ++i) {
+        vhost_vdpa_set_vring_ready(&s->vdpa, i);
+    }
     s->started = true;
 
     /*
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index e4d0101327..0d9d311abd 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1154,9 +1154,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
         if (unlikely(!ok)) {
             return -1;
         }
-        for (int i = 0; i < dev->nvqs; ++i) {
-            vhost_vdpa_set_vring_ready(v, dev->vq_index + i);
-        }
     } else {
         vhost_vdpa_suspend(dev);
         vhost_vdpa_svqs_stop(dev);
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index a1b16bbc52..47b87bf80d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -344,6 +344,22 @@ static int vhost_vdpa_net_data_start(NetClientState *nc)
     return 0;
 }
 
+static int vhost_vdpa_net_data_load(NetClientState *nc)
+{
+    VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
+    struct vhost_vdpa *v = &s->vhost_vdpa;
+    bool has_cvq = v->dev->vq_index_end % 2;
+
+    if (has_cvq) {
+        return 0;
+    }
+
+    for (int i = 0; i < v->dev->nvqs; ++i) {
+        vhost_vdpa_set_vring_ready(v, i + v->dev->vq_index);
+    }
+    return 0;
+}
+
 static void vhost_vdpa_net_client_stop(NetClientState *nc)
 {
     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
@@ -366,6 +382,7 @@ static NetClientInfo net_vhost_vdpa_info = {
         .size = sizeof(VhostVDPAState),
         .receive = vhost_vdpa_receive,
         .start = vhost_vdpa_net_data_start,
+        .load = vhost_vdpa_net_data_load,
         .stop = vhost_vdpa_net_client_stop,
         .cleanup = vhost_vdpa_cleanup,
         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
@@ -682,18 +699,22 @@ static int vhost_vdpa_net_cvq_load(NetClientState *nc)
 
     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
 
-    if (!v->shadow_vqs_enabled) {
-        return 0;
-    }
+    vhost_vdpa_set_vring_ready(v, v->dev->vq_index);
 
-    n = VIRTIO_NET(v->dev->vdev);
-    r = vhost_vdpa_net_load_mac(s, n);
-    if (unlikely(r < 0)) {
-        return r;
+    if (v->shadow_vqs_enabled) {
+        n = VIRTIO_NET(v->dev->vdev);
+        r = vhost_vdpa_net_load_mac(s, n);
+        if (unlikely(r < 0)) {
+            return r;
+        }
+        r = vhost_vdpa_net_load_mq(s, n);
+        if (unlikely(r)) {
+            return r;
+        }
     }
-    r = vhost_vdpa_net_load_mq(s, n);
-    if (unlikely(r)) {
-        return r;
+
+    for (int i = 0; i < v->dev->vq_index; ++i) {
+        vhost_vdpa_set_vring_ready(v, i);
     }
 
     return 0;
-- 
2.39.3