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| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2015-03-13 20:40:50 +1100 |
|---|---|---|
| committer | Alexey Kardashevskiy <aik@ozlabs.ru> | 2015-03-13 22:31:11 +1100 |
| commit | 750aec6ff6638bbf0d3f3f4c752ac8fd77071c04 (patch) | |
| tree | 1f443b1a5f1262d7ca23281c2661fa7ef88e3dce | |
| parent | 8d96fe983fac761677453b06b0d7054db8e681f6 (diff) | |
| download | SLOF-750aec6ff6638bbf0d3f3f4c752ac8fd77071c04.zip SLOF-750aec6ff6638bbf0d3f3f4c752ac8fd77071c04.tar.gz SLOF-750aec6ff6638bbf0d3f3f4c752ac8fd77071c04.tar.bz2 | |
virtio: Fix vring allocation
The value returned by virtio_vring_size() is used to allocate memory
for vring. The used descriptor list (array of vring_used_elem) is
counted by the header - vring_used struct - is not.
This fixes virtio_vring_size() to return the correct size.
At the moment rings are quite small (256) and allocated with
4096 alignment, this is why we have not been having issues with
this so far.
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* remove magic numbers
| -rw-r--r-- | lib/libvirtio/virtio.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/libvirtio/virtio.c b/lib/libvirtio/virtio.c index b010796..f9c00a6 100644 --- a/lib/libvirtio/virtio.c +++ b/lib/libvirtio/virtio.c @@ -32,8 +32,10 @@ */ unsigned long virtio_vring_size(unsigned int qsize) { - return VQ_ALIGN(sizeof(struct vring_desc) * qsize + 2 * (2 + qsize)) - + VQ_ALIGN(sizeof(struct vring_used_elem) * qsize); + return VQ_ALIGN(sizeof(struct vring_desc) * qsize + + sizeof(struct vring_avail) + sizeof(uint16_t) * qsize) + + VQ_ALIGN(sizeof(struct vring_used) + + sizeof(struct vring_used_elem) * qsize); } |