[RFC 1/3] vdpa: support exposing the config size to userspace
From: Longpeng(Mike) <hidden>
Date: 2022-01-17 09:29:37
Also in:
kvm, lkml
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
From: Longpeng <redacted> - GET_CONFIG_SIZE: the size of the virtio config space Signed-off-by: Longpeng <redacted> --- drivers/vhost/vdpa.c | 17 +++++++++++++++++ include/uapi/linux/vhost.h | 4 ++++ 2 files changed, 21 insertions(+)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 29cced1cd277..1eea14a4ea56 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c@@ -355,6 +355,20 @@ static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp) return 0; } +static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + u32 size; + + size = ops->get_config_size(vdpa); + + if (copy_to_user(argp, &size, sizeof(size))) + return -EFAULT; + + return 0; +} + static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, void __user *argp) {
@@ -492,6 +506,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, case VHOST_VDPA_GET_IOVA_RANGE: r = vhost_vdpa_get_iova_range(v, argp); break; + case VHOST_VDPA_GET_CONFIG_SIZE: + r = vhost_vdpa_get_config_size(v, argp); + break; default: r = vhost_dev_ioctl(&v->vdev, cmd, argp); if (r == -ENOIOCTLCMD)
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index c998860d7bbc..bc74e95a273a 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h@@ -150,4 +150,8 @@ /* Get the valid iova range */ #define VHOST_VDPA_GET_IOVA_RANGE _IOR(VHOST_VIRTIO, 0x78, \ struct vhost_vdpa_iova_range) + +/* Get the config size */ +#define VHOST_VDPA_GET_CONFIG_SIZE _IOR(VHOST_VIRTIO, 0x79, __u32) + #endif
--
2.23.0