virtio-net: fix max vring buf size when set ring num

Signed-off-by: Jinhua Cao <caojinhua1@huawei.com>

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

@@ -0,0 +1,50 @@
+From 318f0eda68554af0c779e5374f16bf8cdb895fe7 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
+
+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 ec3e96af3b..03afa36e99 100644
+--- a/hw/virtio/virtio.c
++++ b/hw/virtio/virtio.c
+@@ -2241,12 +2241,17 @@ 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 8bab9cfb75..b3749ce34b 100644
+--- a/include/hw/virtio/virtio.h
++++ b/include/hw/virtio/virtio.h
+@@ -49,6 +49,7 @@ size_t virtio_feature_get_config_size(const VirtIOFeature *features,
+ typedef struct VirtQueue VirtQueue;
+ 
+ #define VIRTQUEUE_MAX_SIZE 1024
++#define VIRTIO_NET_VQ_MAX_SIZE (4096)
+ 
+ typedef struct VirtQueueElement
+ {
+-- 
+2.27.0
+