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References: <20240109111025.1320976-1-maxime.coquelin@redhat.com> <20240109111025.1320976-3-maxime.coquelin@redhat.com>
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From: Yongji Xie <xieyongji@bytedance.com>
Date: Wed, 10 Jan 2024 11:20:53 +0800
Message-ID: <CACycT3sjYzh7Df9M1Bfxk_pWc7Am6AmjQv8_vu6fA2fhP2+7mg@mail.gmail.com>
Subject: Re: [PATCH v7 2/3] vduse: Temporarily fail if control queue feature requested
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>, 
	Xuan Zhuo <xuanzhuo@linux.alibaba.com>, 
	virtualization <virtualization@lists.linux-foundation.org>, 
	linux-kernel <linux-kernel@vger.kernel.org>, David Marchand <david.marchand@redhat.com>, 
	Cindy Lu <lulu@redhat.com>
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On Tue, Jan 9, 2024 at 7:10=E2=80=AFPM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> 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>

Reviewed-by: Xie Yongji <xieyongji@bytedance.com>

Thanks,
Yongji

> ---
>  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_conf=
ig *config)
>         if ((config->device_id =3D=3D VIRTIO_ID_BLOCK) &&
>                         (config->features & BIT_ULL(VIRTIO_BLK_F_CONFIG_W=
CE)))
>                 return false;
> +       else if ((config->device_id =3D=3D VIRTIO_ID_NET) &&
> +                       (config->features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)=
))
> +               return false;
>
>         return true;
>  }
> --
> 2.43.0
>