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
This commit is contained in:
Linus Torvalds 2007-11-12 11:13:31 -08:00
commit 05f3f41589
5 changed files with 34 additions and 20 deletions

View File

@ -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;
}
}

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@ -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;

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@ -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);

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@ -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;

View File

@ -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__