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authorMichael S. Tsirkin <mst@redhat.com>2012-09-05 21:47:45 +0300
committerRusty Russell <rusty@rustcorp.com.au>2012-09-28 15:05:15 +0930
commit6457f126c888b3481fdae6f702e616cd0c79646e (patch)
treeeae794db0b3983d2a901ecf6471eda6e3f9ff26f /drivers/virtio
parent75a0a52be3c27b58654fbed2c8f2ff401482b9a4 (diff)
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virtio: support reserved vqs
virtio network device multiqueue support reserves vq 3 for future use (useful both for future extensions and to make it pretty - this way receive vqs have even and transmit - odd numbers). Make it possible to skip initialization for specific vq numbers by specifying NULL for name. Document this usage as well as (existing) NULL callback. Drivers using this not coded up yet, so I simply tested with virtio-pci and verified that this patch does not break existing drivers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_mmio.c3
-rw-r--r--drivers/virtio/virtio_pci.c5
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 008bf58bdaa..5d7fee385b7 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -306,6 +306,9 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
unsigned long flags, size;
int err;
+ if (!name)
+ return NULL;
+
/* Select the queue we're interested in */
writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index f5dfe6bdb95..42b20769d12 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -555,7 +555,10 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
vp_dev->per_vq_vectors = per_vq_vectors;
allocated_vectors = vp_dev->msix_used_vectors;
for (i = 0; i < nvqs; ++i) {
- if (!callbacks[i] || !vp_dev->msix_enabled)
+ if (!names[i]) {
+ vqs[i] = NULL;
+ continue;
+ } else if (!callbacks[i] || !vp_dev->msix_enabled)
msix_vec = VIRTIO_MSI_NO_VECTOR;
else if (vp_dev->per_vq_vectors)
msix_vec = allocated_vectors++;