This is a note to let you know that I've just added the patch titled vdpa/mlx5: Allow CVQ size changes to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vdpa-mlx5-allow-cvq-size-changes.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5def28ba24600ba82bd1b95bcd837cd2b8f6b2f2 Author: Jonah Palmer <jonah.palmer@xxxxxxxxxx> Date: Fri Feb 16 09:25:02 2024 -0500 vdpa/mlx5: Allow CVQ size changes [ Upstream commit 749a4016839270163efc36ecddddd01de491a16b ] The MLX driver was not updating its control virtqueue size at set_vq_num and instead always initialized to MLX5_CVQ_MAX_ENT (16) at setup_cvq_vring. Qemu would try to set the size to 64 by default, however, because the CVQ size always was initialized to 16, an error would be thrown when sending >16 control messages (as used-ring entry 17 is initialized to 0). For example, starting a guest with x-svq=on and then executing the following command would produce the error below: # for i in {1..20}; do ifconfig eth0 hw ether XX:xx:XX:xx:XX:XX; done qemu-system-x86_64: Insufficient written data (0) [ 435.331223] virtio_net virtio0: Failed to set mac address by vq command. SIOCSIFHWADDR: Invalid argument Acked-by: Dragos Tatulea <dtatulea@xxxxxxxxxx> Acked-by: Eugenio Pérez <eperezma@xxxxxxxxxx> Signed-off-by: Jonah Palmer <jonah.palmer@xxxxxxxxxx> Message-Id: <20240216142502.78095-1-jonah.palmer@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Tested-by: Lei Yang <leiyang@xxxxxxxxxx> Fixes: 5262912ef3cf ("vdpa/mlx5: Add support for control VQ and MAC setting") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 778821bab7d93..ecfc16151d619 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -151,8 +151,6 @@ static void teardown_driver(struct mlx5_vdpa_net *ndev); static bool mlx5_vdpa_debug; -#define MLX5_CVQ_MAX_ENT 16 - #define MLX5_LOG_VIO_FLAG(_feature) \ do { \ if (features & BIT_ULL(_feature)) \ @@ -2276,9 +2274,16 @@ static void mlx5_vdpa_set_vq_num(struct vdpa_device *vdev, u16 idx, u32 num) struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); struct mlx5_vdpa_virtqueue *mvq; - if (!is_index_valid(mvdev, idx) || is_ctrl_vq_idx(mvdev, idx)) + if (!is_index_valid(mvdev, idx)) return; + if (is_ctrl_vq_idx(mvdev, idx)) { + struct mlx5_control_vq *cvq = &mvdev->cvq; + + cvq->vring.vring.num = num; + return; + } + mvq = &ndev->vqs[idx]; mvq->num_ent = num; } @@ -2963,7 +2968,7 @@ static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev) u16 idx = cvq->vring.last_avail_idx; err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features, - MLX5_CVQ_MAX_ENT, false, + cvq->vring.vring.num, false, (struct vring_desc *)(uintptr_t)cvq->desc_addr, (struct vring_avail *)(uintptr_t)cvq->driver_addr, (struct vring_used *)(uintptr_t)cvq->device_addr);