From: Jiang Liu <jiang.liu@linux.intel.com>
Date: Thu, 4 Jun 2015 08:41:44 +0000 (+0800)
Subject: virtio_pci: Clear stale cpumask when setting irq affinity
X-Git-Tag: v3.16.35~1860
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9ca6d16448ea5351ca69e561eed2a34edcbd390a;p=thirdparty%2Fkernel%2Fstable.git

virtio_pci: Clear stale cpumask when setting irq affinity

commit 210d150e1f5da506875e376422ba31ead2d49621 upstream.

The cpumask vp_dev->msix_affinity_masks[info->msix_vector] may contain
staled information when vp_set_vq_affinity() gets called, so clear it
before setting the new cpu bit mask.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[ luis: backported to 3.16:
  - file rename: virtio_pci_common.c -> virtio_pci.c ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 52c4607fec9e4..c09527df161c8 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -645,6 +645,7 @@ static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
 		if (cpu == -1)
 			irq_set_affinity_hint(irq, NULL);
 		else {
+			cpumask_clear(mask);
 			cpumask_set_cpu(cpu, mask);
 			irq_set_affinity_hint(irq, mask);
 		}