qemu/virtio-net-fix-max-vring-buf-size-when-set-ring-num.patch

From 4321c9f8b85c6a4c1549399aa11e351b66bd1879 Mon Sep 17 00:00:00 2001
From: Jinhua Cao <caojinhua1@huawei.com>
Date: Thu, 10 Feb 2022 10:48:27 +0800
Subject: [PATCH] virtio-net: fix max vring buf size when set ring num

Set the max vring buf size of virtio-net devices to 4096

Signed-off-by: Jinhua Cao <caojinhua1@huawei.com>
---
 hw/virtio/virtio.c         | 9 +++++++--
 include/hw/virtio/virtio.h | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index d93ea62723..267c1e6fd0 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2196,12 +2196,17 @@ void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
 
 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
 {
+    int vq_max_size = VIRTQUEUE_MAX_SIZE;
+
+    if (!strcmp(vdev->name, "virtio-net")) {
+        vq_max_size = VIRTIO_NET_VQ_MAX_SIZE;
+    }
+
     /* Don't allow guest to flip queue between existent and
      * nonexistent states, or to set it to an invalid size.
      */
     if (!!num != !!vdev->vq[n].vring.num ||
-        num > VIRTQUEUE_MAX_SIZE ||
-        num < 0) {
+        num > vq_max_size || num < 0) {
         return;
     }
     vdev->vq[n].vring.num = num;
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 7c35bb841b..e612441357 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -60,6 +60,7 @@ size_t virtio_get_config_size(const VirtIOConfigSizeParams *params,
 typedef struct VirtQueue VirtQueue;
 
 #define VIRTQUEUE_MAX_SIZE 1024
+#define VIRTIO_NET_VQ_MAX_SIZE (4096)
 
 typedef struct VirtQueueElement
 {
-- 
2.27.0