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From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: mst@redhat.com,
	jasowang@redhat.com,
	xuanzhuo@linux.alibaba.com,
	xieyongji@bytedance.com,
	virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org,
	david.marchand@redhat.com,
	lulu@redhat.com
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Subject: [PATCH v7 2/3] vduse: Temporarily fail if control queue feature requested
Date: Tue,  9 Jan 2024 12:10:24 +0100
Message-ID: <20240109111025.1320976-3-maxime.coquelin@redhat.com>
In-Reply-To: <20240109111025.1320976-1-maxime.coquelin@redhat.com>
References: <20240109111025.1320976-1-maxime.coquelin@redhat.com>
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Virtio-net driver control queue implementation is not safe
when used with VDUSE. If the VDUSE application does not
reply to control queue messages, it currently ends up
hanging the kernel thread sending this command.

Some work is on-going to make the control queue
implementation robust with VDUSE. Until it is completed,
let's fail features check if control-queue feature is
requested.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index a5af6d4077b8..00f3f562ab5d 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -8,6 +8,7 @@
  *
  */
 
+#include "linux/virtio_net.h"
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/cdev.h>
@@ -28,6 +29,7 @@
 #include <uapi/linux/virtio_config.h>
 #include <uapi/linux/virtio_ids.h>
 #include <uapi/linux/virtio_blk.h>
+#include <uapi/linux/virtio_ring.h>
 #include <linux/mod_devicetable.h>
 
 #include "iova_domain.h"
@@ -1680,6 +1682,9 @@ static bool features_is_valid(struct vduse_dev_config *config)
 	if ((config->device_id == VIRTIO_ID_BLOCK) &&
 			(config->features & BIT_ULL(VIRTIO_BLK_F_CONFIG_WCE)))
 		return false;
+	else if ((config->device_id == VIRTIO_ID_NET) &&
+			(config->features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)))
+		return false;
 
 	return true;
 }
-- 
2.43.0