For the record, the following commit fixes the issue for later kernels (>4.11). What we're seeing with the 4.4 kernel is most likely a different issue though.
commit ba74b6f7fcc07355d087af6939712eed4a454821 (refs/bisect/new) Author: Christoph Hellwig <[email protected]> Date: Thu Aug 24 18:07:02 2017 +0200 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 <[email protected]> Fixes: 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues") Reported-by: YASUAKI ISHIMATSU <[email protected]> Cc: [email protected] Signed-off-by: Michael S. Tsirkin <[email protected]> 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; -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1670634 Title: blk-mq: possible deadlock on CPU hot(un)plug To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1670634/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
