[PATCH 3/7] virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci.

From: Rusty Russell
Date: Wed Nov 12 2008 - 07:23:26 EST


That doesn't work for non-4k guests which are now appearing.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci.c | 5 +++--
include/linux/virtio_pci.h | 4 ++++
2 files changed, 7 insertions(+), 2 deletions(-)

diff -r c6f6a3ab173b drivers/virtio/virtio_pci.c
--- a/drivers/virtio/virtio_pci.c Wed Nov 12 21:51:09 2008 +1030
+++ b/drivers/virtio/virtio_pci.c Wed Nov 12 21:57:25 2008 +1030
@@ -216,7 +216,7 @@
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtio_pci_vq_info *info;
struct virtqueue *vq;
- unsigned long flags;
+ unsigned long flags, size;
u16 num;
int err;

@@ -237,7 +237,8 @@
info->queue_index = index;
info->num = num;

- info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
+ size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
+ info->queue = kzalloc(size, GFP_KERNEL);
if (info->queue == NULL) {
err = -ENOMEM;
goto out_info;
diff -r c6f6a3ab173b include/linux/virtio_pci.h
--- a/include/linux/virtio_pci.h Wed Nov 12 21:51:09 2008 +1030
+++ b/include/linux/virtio_pci.h Wed Nov 12 21:57:25 2008 +1030
@@ -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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/