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Commit feebcaea authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

vhost: factor out setting vring addr and num 



Factoring vring address and num setting which needs special care for
accelerating vq metadata accessing.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 4942e825

drivers/vhost/vhost.c

+103 −74
Original line number Diff line number Diff line
@@ -1486,6 +1486,104 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) 
	return -EFAULT;

}



static long vhost_vring_set_num(struct vhost_dev *d,

				struct vhost_virtqueue *vq,

				void __user *argp)

{

	struct vhost_vring_state s;



	/* Resizing ring with an active backend?

	 * You don't want to do that. */

	if (vq->private_data)

		return -EBUSY;



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

		return -EFAULT;



	if (!s.num || s.num > 0xffff || (s.num & (s.num - 1)))

		return -EINVAL;

	vq->num = s.num;



	return 0;

}



static long vhost_vring_set_addr(struct vhost_dev *d,

				 struct vhost_virtqueue *vq,

				 void __user *argp)

{

	struct vhost_vring_addr a;



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

		return -EFAULT;

	if (a.flags & ~(0x1 << VHOST_VRING_F_LOG))

		return -EOPNOTSUPP;



	/* For 32bit, verify that the top 32bits of the user

	   data are set to zero. */

	if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr ||

	    (u64)(unsigned long)a.used_user_addr != a.used_user_addr ||

	    (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr)

		return -EFAULT;



	/* Make sure it's safe to cast pointers to vring types. */

	BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE);

	BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);

	if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||

	    (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||

	    (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1)))

		return -EINVAL;



	/* We only verify access here if backend is configured.

	 * If it is not, we don't as size might not have been setup.

	 * We will verify when backend is configured. */

	if (vq->private_data) {

		if (!vq_access_ok(vq, vq->num,

			(void __user *)(unsigned long)a.desc_user_addr,

			(void __user *)(unsigned long)a.avail_user_addr,

			(void __user *)(unsigned long)a.used_user_addr))

			return -EINVAL;



		/* Also validate log access for used ring if enabled. */

		if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&

			!log_access_ok(vq->log_base, a.log_guest_addr,

				sizeof *vq->used +

				vq->num * sizeof *vq->used->ring))

			return -EINVAL;

	}



	vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG));

	vq->desc = (void __user *)(unsigned long)a.desc_user_addr;

	vq->avail = (void __user *)(unsigned long)a.avail_user_addr;

	vq->log_addr = a.log_guest_addr;

	vq->used = (void __user *)(unsigned long)a.used_user_addr;



	return 0;

}



static long vhost_vring_set_num_addr(struct vhost_dev *d,

				     struct vhost_virtqueue *vq,

				     unsigned int ioctl,

				     void __user *argp)

{

	long r;



	mutex_lock(&vq->mutex);



	switch (ioctl) {

	case VHOST_SET_VRING_NUM:

		r = vhost_vring_set_num(d, vq, argp);

		break;

	case VHOST_SET_VRING_ADDR:

		r = vhost_vring_set_addr(d, vq, argp);

		break;

	default:

		BUG();

	}



	mutex_unlock(&vq->mutex);



	return r;

}

long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)

{

	struct file *eventfp, *filep = NULL;
@@ -1495,7 +1593,6 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg 
	struct vhost_virtqueue *vq;

	struct vhost_vring_state s;

	struct vhost_vring_file f;

	struct vhost_vring_addr a;

	u32 idx;

	long r;
@@ -1508,26 +1605,14 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg 
	idx = array_index_nospec(idx, d->nvqs);

	vq = d->vqs[idx];



	if (ioctl == VHOST_SET_VRING_NUM ||

	    ioctl == VHOST_SET_VRING_ADDR) {

		return vhost_vring_set_num_addr(d, vq, ioctl, argp);

	}



	mutex_lock(&vq->mutex);



	switch (ioctl) {

	case VHOST_SET_VRING_NUM:

		/* Resizing ring with an active backend?

		 * You don't want to do that. */

		if (vq->private_data) {

			r = -EBUSY;

			break;

		}

		if (copy_from_user(&s, argp, sizeof s)) {

			r = -EFAULT;

			break;

		}

		if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) {

			r = -EINVAL;

			break;

		}

		vq->num = s.num;

		break;

	case VHOST_SET_VRING_BASE:

		/* Moving base with an active backend?

		 * You don't want to do that. */
@@ -1553,62 +1638,6 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg 
		if (copy_to_user(argp, &s, sizeof s))

			r = -EFAULT;

		break;

	case VHOST_SET_VRING_ADDR:

		if (copy_from_user(&a, argp, sizeof a)) {

			r = -EFAULT;

			break;

		}

		if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) {

			r = -EOPNOTSUPP;

			break;

		}

		/* For 32bit, verify that the top 32bits of the user

		   data are set to zero. */

		if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr ||

		    (u64)(unsigned long)a.used_user_addr != a.used_user_addr ||

		    (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) {

			r = -EFAULT;

			break;

		}



		/* Make sure it's safe to cast pointers to vring types. */

		BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE);

		BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);

		if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||

		    (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||

		    (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) {

			r = -EINVAL;

			break;

		}



		/* We only verify access here if backend is configured.

		 * If it is not, we don't as size might not have been setup.

		 * We will verify when backend is configured. */

		if (vq->private_data) {

			if (!vq_access_ok(vq, vq->num,

				(void __user *)(unsigned long)a.desc_user_addr,

				(void __user *)(unsigned long)a.avail_user_addr,

				(void __user *)(unsigned long)a.used_user_addr)) {

				r = -EINVAL;

				break;

			}



			/* Also validate log access for used ring if enabled. */

			if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&

			    !log_access_ok(vq->log_base, a.log_guest_addr,

					   sizeof *vq->used +

					   vq->num * sizeof *vq->used->ring)) {

				r = -EINVAL;

				break;

			}

		}



		vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG));

		vq->desc = (void __user *)(unsigned long)a.desc_user_addr;

		vq->avail = (void __user *)(unsigned long)a.avail_user_addr;

		vq->log_addr = a.log_guest_addr;

		vq->used = (void __user *)(unsigned long)a.used_user_addr;

		break;

	case VHOST_SET_VRING_KICK:

		if (copy_from_user(&f, argp, sizeof f)) {

			r = -EFAULT;