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Commit 3b1bbe89 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

vhost: virtio 1.0 endian-ness support 



Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 64f7f051

drivers/vhost/vhost.c

+49 −37
Original line number Diff line number Diff line
@@ -33,8 +33,8 @@ enum { 
	VHOST_MEMORY_F_LOG = 0x1,

};



#define vhost_used_event(vq) ((u16 __user *)&vq->avail->ring[vq->num])

#define vhost_avail_event(vq) ((u16 __user *)&vq->used->ring[vq->num])

#define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num])

#define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])



static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,

			    poll_table *pt)
@@ -1001,7 +1001,7 @@ EXPORT_SYMBOL_GPL(vhost_log_write); 
static int vhost_update_used_flags(struct vhost_virtqueue *vq)

{

	void __user *used;

	if (__put_user(vq->used_flags, &vq->used->flags) < 0)

	if (__put_user(cpu_to_vhost16(vq, vq->used_flags), &vq->used->flags) < 0)

		return -EFAULT;

	if (unlikely(vq->log_used)) {

		/* Make sure the flag is seen before log. */
@@ -1019,7 +1019,7 @@ static int vhost_update_used_flags(struct vhost_virtqueue *vq) 


static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)

{

	if (__put_user(vq->avail_idx, vhost_avail_event(vq)))

	if (__put_user(cpu_to_vhost16(vq, vq->avail_idx), vhost_avail_event(vq)))

		return -EFAULT;

	if (unlikely(vq->log_used)) {

		void __user *used;
@@ -1038,7 +1038,7 @@ static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) 


int vhost_init_used(struct vhost_virtqueue *vq)

{

	u16 last_used_idx;

	__virtio16 last_used_idx;

	int r;

	if (!vq->private_data)

		return 0;
@@ -1052,7 +1052,7 @@ int vhost_init_used(struct vhost_virtqueue *vq) 
	r = __get_user(last_used_idx, &vq->used->idx);

	if (r)

		return r;

	vq->last_used_idx = last_used_idx;

	vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx);

	return 0;

}

EXPORT_SYMBOL_GPL(vhost_init_used);
@@ -1094,16 +1094,16 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, 
/* Each buffer in the virtqueues is actually a chain of descriptors.  This

 * function returns the next descriptor in the chain,

 * or -1U if we're at the end. */

static unsigned next_desc(struct vring_desc *desc)

static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)

{

	unsigned int next;



	/* If this descriptor says it doesn't chain, we're done. */

	if (!(desc->flags & VRING_DESC_F_NEXT))

	if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT)))

		return -1U;



	/* Check they're not leading us off end of descriptors. */

	next = desc->next;

	next = vhost16_to_cpu(vq, desc->next);

	/* Make sure compiler knows to grab that: we don't want it changing! */

	/* We will use the result as an index in an array, so most

	 * architectures only need a compiler barrier here. */
@@ -1120,18 +1120,19 @@ static int get_indirect(struct vhost_virtqueue *vq, 
{

	struct vring_desc desc;

	unsigned int i = 0, count, found = 0;

	u32 len = vhost32_to_cpu(vq, indirect->len);

	int ret;



	/* Sanity check */

	if (unlikely(indirect->len % sizeof desc)) {

	if (unlikely(len % sizeof desc)) {

		vq_err(vq, "Invalid length in indirect descriptor: "

		       "len 0x%llx not multiple of 0x%zx\n",

		       (unsigned long long)indirect->len,

		       (unsigned long long)len,

		       sizeof desc);

		return -EINVAL;

	}



	ret = translate_desc(vq, indirect->addr, indirect->len, vq->indirect,

	ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect,

			     UIO_MAXIOV);

	if (unlikely(ret < 0)) {

		vq_err(vq, "Translation failure %d in indirect.\n", ret);
@@ -1142,7 +1143,7 @@ static int get_indirect(struct vhost_virtqueue *vq, 
	 * architectures only need a compiler barrier here. */

	read_barrier_depends();



	count = indirect->len / sizeof desc;

	count = len / sizeof desc;

	/* Buffers are chained via a 16 bit next field, so

	 * we can have at most 2^16 of these. */

	if (unlikely(count > USHRT_MAX + 1)) {
@@ -1162,16 +1163,17 @@ static int get_indirect(struct vhost_virtqueue *vq, 
		if (unlikely(memcpy_fromiovec((unsigned char *)&desc,

					      vq->indirect, sizeof desc))) {

			vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",

			       i, (size_t)indirect->addr + i * sizeof desc);

			       i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);

			return -EINVAL;

		}

		if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) {

		if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {

			vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",

			       i, (size_t)indirect->addr + i * sizeof desc);

			       i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);

			return -EINVAL;

		}



		ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count,

		ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),

				     vhost32_to_cpu(vq, desc.len), iov + iov_count,

				     iov_size - iov_count);

		if (unlikely(ret < 0)) {

			vq_err(vq, "Translation failure %d indirect idx %d\n",
@@ -1179,11 +1181,11 @@ static int get_indirect(struct vhost_virtqueue *vq, 
			return ret;

		}

		/* If this is an input descriptor, increment that count. */

		if (desc.flags & VRING_DESC_F_WRITE) {

		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) {

			*in_num += ret;

			if (unlikely(log)) {

				log[*log_num].addr = desc.addr;

				log[*log_num].len = desc.len;

				log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);

				log[*log_num].len = vhost32_to_cpu(vq, desc.len);

				++*log_num;

			}

		} else {
@@ -1196,7 +1198,7 @@ static int get_indirect(struct vhost_virtqueue *vq, 
			}

			*out_num += ret;

		}

	} while ((i = next_desc(&desc)) != -1);

	} while ((i = next_desc(vq, &desc)) != -1);

	return 0;

}
@@ -1216,15 +1218,18 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
	struct vring_desc desc;

	unsigned int i, head, found = 0;

	u16 last_avail_idx;

	__virtio16 avail_idx;

	__virtio16 ring_head;

	int ret;



	/* Check it isn't doing very strange things with descriptor numbers. */

	last_avail_idx = vq->last_avail_idx;

	if (unlikely(__get_user(vq->avail_idx, &vq->avail->idx))) {

	if (unlikely(__get_user(avail_idx, &vq->avail->idx))) {

		vq_err(vq, "Failed to access avail idx at %p\n",

		       &vq->avail->idx);

		return -EFAULT;

	}

	vq->avail_idx = vhost16_to_cpu(vq, avail_idx);



	if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {

		vq_err(vq, "Guest moved used index from %u to %u",
@@ -1241,7 +1246,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 


	/* Grab the next descriptor number they're advertising, and increment

	 * the index we've seen. */

	if (unlikely(__get_user(head,

	if (unlikely(__get_user(ring_head,

				&vq->avail->ring[last_avail_idx % vq->num]))) {

		vq_err(vq, "Failed to read head: idx %d address %p\n",

		       last_avail_idx,
@@ -1249,6 +1254,8 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
		return -EFAULT;

	}



	head = vhost16_to_cpu(vq, ring_head);



	/* If their number is silly, that's an error. */

	if (unlikely(head >= vq->num)) {

		vq_err(vq, "Guest says index %u > %u is available",
@@ -1281,7 +1288,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
			       i, vq->desc + i);

			return -EFAULT;

		}

		if (desc.flags & VRING_DESC_F_INDIRECT) {

		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {

			ret = get_indirect(vq, iov, iov_size,

					   out_num, in_num,

					   log, log_num, &desc);
@@ -1293,20 +1300,21 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
			continue;

		}



		ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count,

		ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),

				     vhost32_to_cpu(vq, desc.len), iov + iov_count,

				     iov_size - iov_count);

		if (unlikely(ret < 0)) {

			vq_err(vq, "Translation failure %d descriptor idx %d\n",

			       ret, i);

			return ret;

		}

		if (desc.flags & VRING_DESC_F_WRITE) {

		if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) {

			/* If this is an input descriptor,

			 * increment that count. */

			*in_num += ret;

			if (unlikely(log)) {

				log[*log_num].addr = desc.addr;

				log[*log_num].len = desc.len;

				log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);

				log[*log_num].len = vhost32_to_cpu(vq, desc.len);

				++*log_num;

			}

		} else {
@@ -1319,7 +1327,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, 
			}

			*out_num += ret;

		}

	} while ((i = next_desc(&desc)) != -1);

	} while ((i = next_desc(vq, &desc)) != -1);



	/* On success, increment avail index. */

	vq->last_avail_idx++;
@@ -1342,7 +1350,10 @@ EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); 
 * want to notify the guest, using eventfd. */

int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)

{

	struct vring_used_elem heads = { head, len };

	struct vring_used_elem heads = {

		cpu_to_vhost32(vq, head),

		cpu_to_vhost32(vq, len)

	};



	return vhost_add_used_n(vq, &heads, 1);

}
@@ -1411,7 +1422,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, 


	/* Make sure buffer is written before we update index. */

	smp_wmb();

	if (__put_user(vq->last_used_idx, &vq->used->idx)) {

	if (__put_user(cpu_to_vhost16(vq, vq->last_used_idx), &vq->used->idx)) {

		vq_err(vq, "Failed to increment used idx");

		return -EFAULT;

	}
@@ -1429,7 +1440,8 @@ EXPORT_SYMBOL_GPL(vhost_add_used_n); 


static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)

{

	__u16 old, new, event;

	__u16 old, new;

	__virtio16 event;

	bool v;

	/* Flush out used index updates. This is paired

	 * with the barrier that the Guest executes when enabling
@@ -1441,12 +1453,12 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
		return true;



	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {

		__u16 flags;

		__virtio16 flags;

		if (__get_user(flags, &vq->avail->flags)) {

			vq_err(vq, "Failed to get flags");

			return true;

		}

		return !(flags & VRING_AVAIL_F_NO_INTERRUPT);

		return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT));

	}

	old = vq->signalled_used;

	v = vq->signalled_used_valid;
@@ -1460,7 +1472,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
		vq_err(vq, "Failed to get used event idx");

		return true;

	}

	return vring_need_event(event, new, old);

	return vring_need_event(vhost16_to_cpu(vq, event), new, old);

}



/* This actually signals the guest, using eventfd. */
@@ -1495,7 +1507,7 @@ EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); 
/* OK, now we need to know about added descriptors. */

bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)

{

	u16 avail_idx;

	__virtio16 avail_idx;

	int r;



	if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
@@ -1526,7 +1538,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
		return false;

	}



	return avail_idx != vq->avail_idx;

	return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx;

}

EXPORT_SYMBOL_GPL(vhost_enable_notify);