Add an ioctl to allow VDUSE instances to query the available features supported by the kernel module.
Signed-off-by: Eugenio Pérez <[email protected]> --- v4: * Store the features in VDUSE control instead of vduse device config. v3: * Remove check for API_VERSION < 2 * Add comment about struct vduse_dev_config:vduse_features is only valid if VDUSE_GET_FEATURES success. v2: * return -EINVAL if ioctl called with version < 2, so userland visible reply is kept (Jason). --- drivers/vdpa/vdpa_user/vduse_dev.c | 7 +++++++ include/uapi/linux/vduse.h | 3 +++ 2 files changed, 10 insertions(+) diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 2af5cb5e1ec6..e1930e38df7a 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -52,6 +52,9 @@ #define IRQ_UNBOUND -1 +/* Supported VDUSE features */ +static const uint64_t vduse_features; + /* * VDUSE instance have not asked the vduse API version, so assume 0. * @@ -2343,6 +2346,10 @@ static long vduse_ioctl(struct file *file, unsigned int cmd, ret = vduse_destroy_dev(name); break; } + case VDUSE_GET_FEATURES: + ret = put_user(vduse_features, (u64 __user *)argp); + break; + default: ret = -EINVAL; break; diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h index 361eea511c21..89aa3b448c0a 100644 --- a/include/uapi/linux/vduse.h +++ b/include/uapi/linux/vduse.h @@ -63,6 +63,9 @@ struct vduse_dev_config { */ #define VDUSE_DESTROY_DEV _IOW(VDUSE_BASE, 0x03, char[VDUSE_NAME_MAX]) +/* Get the VDUSE supported features */ +#define VDUSE_GET_FEATURES _IOR(VDUSE_BASE, 0x04, __u64) + /* The ioctls for VDUSE device (/dev/vduse/$NAME) */ /** -- 2.55.0
