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authorChristoph Hellwig <hch@lst.de>2017-08-24 19:07:02 +0300
committerMichael S. Tsirkin <mst@redhat.com>2017-08-25 21:38:26 +0300
commitba74b6f7fcc07355d087af6939712eed4a454821 (patch)
tree2bf5ad11505220311429dc6f0403d5765b3ff624
parent1046d304900cf9d4b2c730c6860b8e03cc704377 (diff)
downloadlinux-ba74b6f7fcc07355d087af6939712eed4a454821.tar.xz
virtio_pci: fix cpu affinity support
Commit 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues"") removed the adjustment of the pre_vectors for the virtio MSI-X vector allocation which was added in commit fb5e31d9 ("virtio: allow drivers to request IRQ affinity when creating VQs"). This will lead to an incorrect assignment of MSI-X vectors, and potential deadlocks when offlining cpus. Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues") Reported-by: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--drivers/virtio/virtio_pci_common.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 007a4f366086..1c4797e53f68 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -107,6 +107,7 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
const char *name = dev_name(&vp_dev->vdev.dev);
+ unsigned flags = PCI_IRQ_MSIX;
unsigned i, v;
int err = -ENOMEM;
@@ -126,10 +127,13 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
GFP_KERNEL))
goto error;
+ if (desc) {
+ flags |= PCI_IRQ_AFFINITY;
+ desc->pre_vectors++; /* virtio config vector */
+ }
+
err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
- nvectors, PCI_IRQ_MSIX |
- (desc ? PCI_IRQ_AFFINITY : 0),
- desc);
+ nvectors, flags, desc);
if (err < 0)
goto error;
vp_dev->msix_enabled = 1;