On Fri, Oct 20, 2023 at 11:58 PM Maxime Coquelin
<maxime.coquelin@xxxxxxxxxx> 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 disable control virtqueue and features that depend on
> it.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
I wonder if it's better to do this with patch 2 or before patch 2 to
unbreak the bisection?
Thanks
> ---
> drivers/vdpa/vdpa_user/vduse_dev.c | 37 ++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 73ad3b7efd8e..0243dee9cf0e 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -28,6 +28,7 @@
> #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"
> @@ -46,6 +47,30 @@
>
> #define IRQ_UNBOUND -1
>
> +#define VDUSE_NET_VALID_FEATURES_MASK \
> + (BIT_ULL(VIRTIO_NET_F_CSUM) | \
> + BIT_ULL(VIRTIO_NET_F_GUEST_CSUM) | \
> + BIT_ULL(VIRTIO_NET_F_MTU) | \
> + BIT_ULL(VIRTIO_NET_F_MAC) | \
> + BIT_ULL(VIRTIO_NET_F_GUEST_TSO4) | \
> + BIT_ULL(VIRTIO_NET_F_GUEST_TSO6) | \
> + BIT_ULL(VIRTIO_NET_F_GUEST_ECN) | \
> + BIT_ULL(VIRTIO_NET_F_GUEST_UFO) | \
> + BIT_ULL(VIRTIO_NET_F_HOST_TSO4) | \
> + BIT_ULL(VIRTIO_NET_F_HOST_TSO6) | \
> + BIT_ULL(VIRTIO_NET_F_HOST_ECN) | \
> + BIT_ULL(VIRTIO_NET_F_HOST_UFO) | \
> + BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) | \
> + BIT_ULL(VIRTIO_NET_F_STATUS) | \
> + BIT_ULL(VIRTIO_NET_F_HOST_USO) | \
> + BIT_ULL(VIRTIO_F_ANY_LAYOUT) | \
> + BIT_ULL(VIRTIO_RING_F_INDIRECT_DESC) | \
> + BIT_ULL(VIRTIO_RING_F_EVENT_IDX) | \
> + BIT_ULL(VIRTIO_F_VERSION_1) | \
> + BIT_ULL(VIRTIO_F_ACCESS_PLATFORM) | \
> + BIT_ULL(VIRTIO_F_RING_PACKED) | \
> + BIT_ULL(VIRTIO_F_IN_ORDER))
> +
> struct vduse_virtqueue {
> u16 index;
> u16 num_max;
> @@ -1778,6 +1803,16 @@ static struct attribute *vduse_dev_attrs[] = {
>
> ATTRIBUTE_GROUPS(vduse_dev);
>
> +static void vduse_dev_features_filter(struct vduse_dev_config *config)
> +{
> + /*
> + * Temporarily filter out virtio-net's control virtqueue and features
> + * that depend on it while CVQ is being made more robust for VDUSE.
> + */
> + if (config->device_id == VIRTIO_ID_NET)
> + config->features &= VDUSE_NET_VALID_FEATURES_MASK;
> +}
> +
> static int vduse_create_dev(struct vduse_dev_config *config,
> void *config_buf, u64 api_version)
> {
> @@ -1793,6 +1828,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
> if (!dev)
> goto err;
>
> + vduse_dev_features_filter(config);
> +
> dev->api_version = api_version;
> dev->device_features = config->features;
> dev->device_id = config->device_id;
> --
> 2.41.0
>
