Commit ad146355 authored by Xie Yongji's avatar Xie Yongji Committed by Michael S. Tsirkin
Browse files

vduse: Support querying information of IOVA regions 



This introduces a new ioctl: VDUSE_IOTLB_GET_INFO to
support querying some information of IOVA regions.

Now it can be used to query whether the IOVA region
supports userspace memory registration.

Signed-off-by: default avatarXie Yongji <xieyongji@bytedance.com>
Message-Id: <20220803045523.23851-6-xieyongji@bytedance.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
parent 79a463be

drivers/vdpa/vdpa_user/vduse_dev.c

+39 −0
Original line number Diff line number Diff line
@@ -1228,6 +1228,45 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, 
					   umem.size);

		break;

	}

	case VDUSE_IOTLB_GET_INFO: {

		struct vduse_iova_info info;

		struct vhost_iotlb_map *map;

		struct vduse_iova_domain *domain = dev->domain;



		ret = -EFAULT;

		if (copy_from_user(&info, argp, sizeof(info)))

			break;



		ret = -EINVAL;

		if (info.start > info.last)

			break;



		if (!is_mem_zero((const char *)info.reserved,

				 sizeof(info.reserved)))

			break;



		spin_lock(&domain->iotlb_lock);

		map = vhost_iotlb_itree_first(domain->iotlb,

					      info.start, info.last);

		if (map) {

			info.start = map->start;

			info.last = map->last;

			info.capability = 0;

			if (domain->bounce_map && map->start == 0 &&

			    map->last == domain->bounce_size - 1)

				info.capability |= VDUSE_IOVA_CAP_UMEM;

		}

		spin_unlock(&domain->iotlb_lock);

		if (!map)

			break;



		ret = -EFAULT;

		if (copy_to_user(argp, &info, sizeof(info)))

			break;



		ret = 0;

		break;

	}

	default:

		ret = -ENOIOCTLCMD;

		break;

include/uapi/linux/vduse.h

+24 −0
Original line number Diff line number Diff line
@@ -233,6 +233,30 @@ struct vduse_iova_umem { 
/* De-register the userspace memory. Caller should set iova and size field. */

#define VDUSE_IOTLB_DEREG_UMEM	_IOW(VDUSE_BASE, 0x19, struct vduse_iova_umem)



/**

 * struct vduse_iova_info - information of one IOVA region

 * @start: start of the IOVA region

 * @last: last of the IOVA region

 * @capability: capability of the IOVA regsion

 * @reserved: for future use, needs to be initialized to zero

 *

 * Structure used by VDUSE_IOTLB_GET_INFO ioctl to get information of

 * one IOVA region.

 */

struct vduse_iova_info {

	__u64 start;

	__u64 last;

#define VDUSE_IOVA_CAP_UMEM (1 << 0)

	__u64 capability;

	__u64 reserved[3];

};



/*

 * Find the first IOVA region that overlaps with the range [start, last]

 * and return some information on it. Caller should set start and last fields.

 */

#define VDUSE_IOTLB_GET_INFO	_IOWR(VDUSE_BASE, 0x1a, struct vduse_iova_info)



/* The control messages definition for read(2)/write(2) on /dev/vduse/$NAME */



/**