Re: [PATCH 3/3] vDPA/ifcvf: get_config_size should return dev specific config size
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2021-04-15 08:12:50
Also in:
kvm, lkml, virtualization
On Wed, Apr 14, 2021 at 05:18:32PM +0800, Zhu Lingshan wrote:
quoted hunk ↗ jump to hunk
get_config_size() should return the size based on the decected device type. Signed-off-by: Zhu Lingshan <redacted> --- drivers/vdpa/ifcvf/ifcvf_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c index 9b6a38b798fa..b48b9789b69e 100644 --- a/drivers/vdpa/ifcvf/ifcvf_main.c +++ b/drivers/vdpa/ifcvf/ifcvf_main.c@@ -347,7 +347,16 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev) { - return sizeof(struct virtio_net_config); + struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev); + size_t size; + + if (vf->dev_type == VIRTIO_ID_NET) + size = sizeof(struct virtio_net_config); + + if (vf->dev_type == VIRTIO_ID_BLOCK) + size = sizeof(struct virtio_blk_config); + + return size;
I'm not familiar with the ifcvf details, but can it happen that the
device is not block or net?
Should we set `size` to 0 by default to handle this case or are we sure
it's one of the two?
Maybe we should add a comment or a warning message in this case, to
prevent some analysis tool or compiler from worrying that `size` might
be uninitialized.
I was thinking something like this:
switch(vf->dev_type) {
case VIRTIO_ID_NET:
size = sizeof(struct virtio_net_config);
break;
case VIRTIO_ID_BLOCK:
size = sizeof(struct virtio_blk_config);
break;
default:
/* or WARN(1, "") if dev_warn() not apply */
dev_warn(... , "virtio ID [0x%x] not supported\n")
size = 0;
}
Thanks,
Stefano