This is a note to let you know that I've just added the patch titled
virtio_pci: fix cpu affinity support
to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio_pci-fix-cpu-affinity-support.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ba74b6f7fcc07355d087af6939712eed4a454821 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@xxxxxx>
Date: Thu, 24 Aug 2017 18:07:02 +0200
Subject: virtio_pci: fix cpu affinity support
From: Christoph Hellwig <hch@xxxxxx>
commit ba74b6f7fcc07355d087af6939712eed4a454821 upstream.
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@xxxxxx>
Fixes: 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues")
Reported-by: YASUAKI ISHIMATSU <yasu.isimatu@xxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -107,6 +107,7 @@ static int vp_request_msix_vectors(struc
{
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(struc
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;
Patches currently in stable-queue which might be from hch@xxxxxx are
queue-4.12/virtio_pci-fix-cpu-affinity-support.patch
queue-4.12/x86-mm-fix-use-after-free-of-ldt_struct.patch
queue-4.12/dax-fix-deadlock-due-to-misaligned-pmd-faults.patch