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-rw-r--r--Documentation/lguest/lguest.c17
-rw-r--r--drivers/lguest/lguest_device.c3
-rw-r--r--drivers/net/virtio_net.c3
-rw-r--r--drivers/virtio/virtio_ring.c10
-rw-r--r--include/linux/virtio_ring.h21
5 files changed, 34 insertions, 20 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index f2668390e8f..42008395534 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -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;
}
}
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index 8904f72f97c..66f38722253 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -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;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index e396c9d2af8..a75be57fb20 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -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);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0e4baca21b8..1dc04b6684e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -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;
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index ac69e7bb5a1..1a4ed49f647 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -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__
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 14:15:21 +0000