From 30a03dfcbbdac22ade72a38b953e0709fbf35baa Mon Sep 17 00:00:00 2001 From: Wu Zongyong Date: Fri, 29 Oct 2021 17:14:47 +0800 Subject: virtio_vdpa: setup correct vq size with callbacks get_vq_num_{max,min} For the devices which implement the get_vq_num_min callback, the driver should not negotiate with virtqueue size with the backend vdpa device if the value returned by get_vq_num_min equals to the value returned by get_vq_num_max. This is useful for vdpa devices based on legacy virtio specfication. Signed-off-by: Wu Zongyong Link: https://lore.kernel.org/r/bc0551cec6c3f3dd9424b678b7c22d882aebab3a.1635493219.git.wuzongyong@linux.alibaba.com Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_vdpa.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c index 72eaef2caeb1..6b62aaf08cc5 100644 --- a/drivers/virtio/virtio_vdpa.c +++ b/drivers/virtio/virtio_vdpa.c @@ -145,7 +145,8 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, /* Assume split virtqueue, switch to packed if necessary */ struct vdpa_vq_state state = {0}; unsigned long flags; - u32 align, num; + u32 align, max_num, min_num = 1; + bool may_reduce_num = true; int err; if (!name) @@ -163,16 +164,21 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, if (!info) return ERR_PTR(-ENOMEM); - num = ops->get_vq_num_max(vdpa); - if (num == 0) { + max_num = ops->get_vq_num_max(vdpa); + if (max_num == 0) { err = -ENOENT; goto error_new_virtqueue; } + if (ops->get_vq_num_min) + min_num = ops->get_vq_num_min(vdpa); + + may_reduce_num = (max_num == min_num) ? false : true; + /* Create the vring */ align = ops->get_vq_align(vdpa); - vq = vring_create_virtqueue(index, num, align, vdev, - true, true, ctx, + vq = vring_create_virtqueue(index, max_num, align, vdev, + true, may_reduce_num, ctx, virtio_vdpa_notify, callback, name); if (!vq) { err = -ENOMEM; -- cgit v1.2.3