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Commit 05f3f415 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-virtio 

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-virtio:
  virtio: Force use of power-of-two for descriptor ring sizes
  lguest: Fix lguest virtio-blk backend size computation
  virtio: Fix used_idx wrap-around
  virtio: more fallout from scatterlist changes.
  virtio: fix vring_init for 64 bits
parents e697b8d1 42b36cc0

Documentation/lguest/lguest.c

+9 −8
Original line number Diff line number Diff line
@@ -62,8 +62,8 @@ typedef uint8_t u8; 
#endif

/* We can have up to 256 pages for devices. */

#define DEVICE_PAGES 256

/* This fits nicely in a single 4096-byte page. */

#define VIRTQUEUE_NUM 127

/* This will occupy 2 pages: it must be a power of 2. */

#define VIRTQUEUE_NUM 128



/*L:120 verbose is both a global flag and a macro.  The C preprocessor allows

 * this, and although I wouldn't recommend it, it works quite nicely here. */
@@ -1036,7 +1036,8 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, 
	void *p;



	/* First we need some pages for this virtqueue. */

	pages = (vring_size(num_descs) + getpagesize() - 1) / getpagesize();

	pages = (vring_size(num_descs, getpagesize()) + getpagesize() - 1)

		/ getpagesize();

	p = get_pages(pages);



	/* Initialize the configuration. */
@@ -1045,7 +1046,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, 
	vq->config.pfn = to_guest_phys(p) / getpagesize();



	/* Initialize the vring. */

	vring_init(&vq->vring, num_descs, p);

	vring_init(&vq->vring, num_descs, p, getpagesize());



	/* Add the configuration information to this device's descriptor. */

	add_desc_field(dev, VIRTIO_CONFIG_F_VIRTQUEUE,
@@ -1342,7 +1343,7 @@ static bool service_io(struct device *dev) 
	if (out->type & VIRTIO_BLK_T_SCSI_CMD) {

		fprintf(stderr, "Scsi commands unsupported\n");

		in->status = VIRTIO_BLK_S_UNSUPP;

		wlen = sizeof(in);

		wlen = sizeof(*in);

	} else if (out->type & VIRTIO_BLK_T_OUT) {

		/* Write */
@@ -1363,7 +1364,7 @@ static bool service_io(struct device *dev) 
			/* Die, bad Guest, die. */

			errx(1, "Write past end %llu+%u", off, ret);

		}

		wlen = sizeof(in);

		wlen = sizeof(*in);

		in->status = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);

	} else {

		/* Read */
@@ -1376,10 +1377,10 @@ static bool service_io(struct device *dev) 
		ret = readv(vblk->fd, iov+1, in_num-1);

		verbose("READ from sector %llu: %i\n", out->sector, ret);

		if (ret >= 0) {

			wlen = sizeof(in) + ret;

			wlen = sizeof(*in) + ret;

			in->status = VIRTIO_BLK_S_OK;

		} else {

			wlen = sizeof(in);

			wlen = sizeof(*in);

			in->status = VIRTIO_BLK_S_IOERR;

		}

	}

drivers/lguest/lguest_device.c

+2 −1
Original line number Diff line number Diff line
@@ -200,7 +200,8 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, 


	/* Figure out how many pages the ring will take, and map that memory */

	lvq->pages = lguest_map((unsigned long)lvq->config.pfn << PAGE_SHIFT,

				DIV_ROUND_UP(vring_size(lvq->config.num),

				DIV_ROUND_UP(vring_size(lvq->config.num,

							PAGE_SIZE),

					     PAGE_SIZE));

	if (!lvq->pages) {

		err = -ENOMEM;

drivers/net/virtio_net.c

+3 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ static void try_fill_recv(struct virtnet_info *vi) 
	struct scatterlist sg[1+MAX_SKB_FRAGS];

	int num, err;



	sg_init_table(sg, 1+MAX_SKB_FRAGS);

	for (;;) {

		skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);

		if (unlikely(!skb))
@@ -231,6 +232,8 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev) 
	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;

	DECLARE_MAC_BUF(mac);



	sg_init_table(sg, 1+MAX_SKB_FRAGS);



	pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));



	free_old_xmit_skbs(vi);

drivers/virtio/virtio_ring.c

+8 −2
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ struct vring_virtqueue 
	unsigned int num_added;



	/* Last used index we've seen. */

	unsigned int last_used_idx;

	u16 last_used_idx;



	/* How to notify other side. FIXME: commonalize hcalls! */

	void (*notify)(struct virtqueue *vq);
@@ -277,11 +277,17 @@ struct virtqueue *vring_new_virtqueue(unsigned int num, 
	struct vring_virtqueue *vq;

	unsigned int i;



	/* We assume num is a power of 2. */

	if (num & (num - 1)) {

		dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);

		return NULL;

	}



	vq = kmalloc(sizeof(*vq) + sizeof(void *)*num, GFP_KERNEL);

	if (!vq)

		return NULL;



	vring_init(&vq->vring, num, pages);

	vring_init(&vq->vring, num, pages, PAGE_SIZE);

	vq->vq.callback = callback;

	vq->vq.vdev = vdev;

	vq->vq.vq_ops = &vring_vq_ops;

include/linux/virtio_ring.h

+12 −9
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ struct vring { 
};



/* The standard layout for the ring is a continuous chunk of memory which looks

 * like this.  The used fields will be aligned to a "num+1" boundary.

 * like this.  We assume num is a power of 2.

 *

 * struct vring

 * {
@@ -79,8 +79,8 @@ struct vring { 
 *	__u16 avail_idx;

 *	__u16 available[num];

 *

 *	// Padding so a correctly-chosen num value will cache-align used_idx.

 *	char pad[sizeof(struct vring_desc) - sizeof(avail_flags)];

 *	// Padding to the next page boundary.

 *	char pad[];

 *

 *	// A ring of used descriptor heads with free-running index.

 *	__u16 used_flags;
@@ -88,18 +88,21 @@ struct vring { 
 *	struct vring_used_elem used[num];

 * };

 */

static inline void vring_init(struct vring *vr, unsigned int num, void *p)

static inline void vring_init(struct vring *vr, unsigned int num, void *p,

			      unsigned int pagesize)

{

	vr->num = num;

	vr->desc = p;

	vr->avail = p + num*sizeof(struct vring);

	vr->used = p + (num+1)*(sizeof(struct vring) + sizeof(__u16));

	vr->avail = p + num*sizeof(struct vring_desc);

	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + pagesize-1)

			    & ~(pagesize - 1));

}



static inline unsigned vring_size(unsigned int num)

static inline unsigned vring_size(unsigned int num, unsigned int pagesize)

{

	return (num + 1) * (sizeof(struct vring_desc) + sizeof(__u16))

		+ sizeof(__u32) + num * sizeof(struct vring_used_elem);

	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)

		 + pagesize - 1) & ~(pagesize - 1))

		+ sizeof(__u16) * 2 + sizeof(struct vring_used_elem) * num;

}



#ifdef __KERNEL__