virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci. That doesn't work for non-4k guests which are now appearing. Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 4 ++-- include/linux/virtio_pci.h | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -237,7 +237,7 @@ static struct virtqueue *vp_find_vq(stru info->queue_index = index; info->num = num; - size = PAGE_ALIGN(vring_size(num, PAGE_SIZE)); + size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN)); info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); if (info->queue == NULL) { err = -ENOMEM; @@ -290,7 +290,7 @@ static void vp_del_vq(struct virtqueue * iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); - size = PAGE_ALIGN(vring_size(info->num, PAGE_SIZE)); + size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN)); free_pages_exact(info->queue, size); kfree(info); } diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h --- a/include/linux/virtio_pci.h +++ b/include/linux/virtio_pci.h @@ -57,4 +57,8 @@ /* How many bits to shift physical queue address written to QUEUE_PFN. * 12 is historical, and due to x86 page size. */ #define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 + +/* The alignment to use between consumer and producer parts of vring. + * x86 pagesize again. */ +#define VIRTIO_PCI_VRING_ALIGN 4096 #endif