From 4d125de3a5d130054df2285e542c1491d214d3e8 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 7 Nov 2007 16:34:49 +1100 Subject: virtio: more fallout from scatterlist changes. This fixes OOPS in network driver when CONFIG_DEBUG_SG=y. Signed-off-by: Rusty Russell --- drivers/net/virtio_net.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers') 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); -- cgit v1.2.3 From 1bc4953ed44454c7f53d0b609445d1534981ee75 Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Wed, 7 Nov 2007 15:49:24 -0600 Subject: virtio: Fix used_idx wrap-around The more_used() function compares the vq->vring.used->idx with last_used_idx. Since vq->vring.used->idx is a 16-bit integer, and last_used_idx is an unsigned int, this results in unpredictable behavior when vq->vring.used->idx wraps around. This patch corrects this by changing last_used_idx to the correct type. Signed-off-by: Anthony Liguori Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0e4baca21b8..0e1bf053d8c 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); -- cgit v1.2.3 From 42b36cc0ce717deeb10030141a43dede763a3ebe Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 12 Nov 2007 13:39:18 +1100 Subject: virtio: Force use of power-of-two for descriptor ring sizes The virtio descriptor rings of size N-1 were nicely set up to be aligned to an N-byte boundary. But as Anthony Liguori points out, the free-running indices used by virtio require that the sizes be a power of 2, otherwise we get problems on wrap (demonstrated with lguest). So we replace the clever "2^n-1" scheme with a simple "align to page boundary" scheme: this means that all virtio rings take at least two pages, but it's safer than guessing cache alignment. Signed-off-by: Rusty Russell --- drivers/lguest/lguest_device.c | 3 ++- drivers/virtio/virtio_ring.c | 8 +++++++- 2 files changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers') 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/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 0e1bf053d8c..1dc04b6684e 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -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; -- cgit v1.2.3