From 56f4bebc591893e590481617da7cd7ecffeb166d Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>

Date: Tue, 23 Aug 2022 20:30:34 +0200

Subject: [PATCH 19/23] vdpa: extract vhost_vdpa_net_cvq_add from

 vhost_vdpa_net_handle_ctrl_avail

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RH-Author: Eugenio Pérez <eperezma@redhat.com>

RH-MergeRequest: 116: vdpa: Restore device state on destination

RH-Bugzilla: 2114060

RH-Acked-by: Cindy Lu <lulu@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

RH-Commit: [18/21] 08ab71dbf050f5c2e97c622d1915f71a56c135b8 (eperezmartin/qemu-kvm)

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2114060

Upstream status: git@github.com:jasowang/qemu.git net-next

So we can reuse it to inject state messages.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

Acked-by: Jason Wang <jasowang@redhat.com>

--

v7:

* Remove double free error

v6:

* Do not assume in buffer sent to the device is sizeof(virtio_net_ctrl_ack)

v5:

* Do not use an artificial !NULL VirtQueueElement

* Use only out size instead of iovec dev_buffers for these functions.

Signed-off-by: Jason Wang <jasowang@redhat.com>

(cherry picked from commit d9afb1f0ee4d662ed67d3bc1220b943f7e4cfa6f)

---

 net/vhost-vdpa.c | 59 +++++++++++++++++++++++++++++++-----------------

 1 file changed, 38 insertions(+), 21 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c

index 17626feb8d..f09f044ec1 100644

--- a/net/vhost-vdpa.c

+++ b/net/vhost-vdpa.c

@@ -331,6 +331,38 @@ static void vhost_vdpa_net_cvq_stop(NetClientState *nc)

     }

 }

+static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s, size_t out_len,

+                                      size_t in_len)

+{

+    /* Buffers for the device */

+    const struct iovec out = {

+        .iov_base = s->cvq_cmd_out_buffer,

+        .iov_len = out_len,

+    };

+    const struct iovec in = {

+        .iov_base = s->cvq_cmd_in_buffer,

+        .iov_len = sizeof(virtio_net_ctrl_ack),

+    };

+    VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);

+    int r;

+

+    r = vhost_svq_add(svq, &out, 1, &in, 1, NULL);

+    if (unlikely(r != 0)) {

+        if (unlikely(r == -ENOSPC)) {

+            qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",

+                          __func__);

+        }

+        return r;

+    }

+

+    /*

+     * We can poll here since we've had BQL from the time we sent the

+     * descriptor. Also, we need to take the answer before SVQ pulls by itself,

+     * when BQL is released

+     */

+    return vhost_svq_poll(svq);

+}

+

 static NetClientInfo net_vhost_vdpa_cvq_info = {

     .type = NET_CLIENT_DRIVER_VHOST_VDPA,

     .size = sizeof(VhostVDPAState),

@@ -387,23 +419,18 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,

                                             void *opaque)

 {

     VhostVDPAState *s = opaque;

-    size_t in_len, dev_written;

+    size_t in_len;

     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;

     /* Out buffer sent to both the vdpa device and the device model */

     struct iovec out = {

         .iov_base = s->cvq_cmd_out_buffer,

     };

-    /* In buffer sent to the device */

-    const struct iovec dev_in = {

-        .iov_base = s->cvq_cmd_in_buffer,

-        .iov_len = sizeof(virtio_net_ctrl_ack),

-    };

     /* in buffer used for device model */

     const struct iovec in = {

         .iov_base = &status,

         .iov_len = sizeof(status),

     };

-    int r = -EINVAL;

+    ssize_t dev_written = -EINVAL;

     bool ok;

     out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,

@@ -414,21 +441,11 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,

         goto out;

     }

-    r = vhost_svq_add(svq, &out, 1, &dev_in, 1, elem);

-    if (unlikely(r != 0)) {

-        if (unlikely(r == -ENOSPC)) {

-            qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",

-                          __func__);

-        }

+    dev_written = vhost_vdpa_net_cvq_add(s, out.iov_len, sizeof(status));

+    if (unlikely(dev_written < 0)) {

         goto out;

     }

-    /*

-     * We can poll here since we've had BQL from the time we sent the

-     * descriptor. Also, we need to take the answer before SVQ pulls by itself,

-     * when BQL is released

-     */

-    dev_written = vhost_svq_poll(svq);

     if (unlikely(dev_written < sizeof(status))) {

         error_report("Insufficient written data (%zu)", dev_written);

         goto out;

@@ -436,7 +453,7 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,

     memcpy(&status, s->cvq_cmd_in_buffer, sizeof(status));

     if (status != VIRTIO_NET_OK) {

-        goto out;

+        return VIRTIO_NET_ERR;

     }

     status = VIRTIO_NET_ERR;

@@ -453,7 +470,7 @@ out:

     }

     vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));

     g_free(elem);

-    return r;

+    return dev_written < 0 ? dev_written : 0;

 }

 static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {

-- 

2.31.1