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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>
zero-colors
Christoph Hellwig 2017-08-24 18:07:02 +02:00 committed by Michael S. Tsirkin
parent 1046d30490
commit ba74b6f7fc
1 changed files with 7 additions and 3 deletions
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10
drivers/virtio/virtio_pci_common.c
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@ -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;