[3.19.y-ckt stable] Patch "virtio_pci: Clear stale cpumask when setting irq affinity" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    virtio_pci: Clear stale cpumask when setting irq affinity

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 687cd0e6d5733f7f54812a9612c54ab0ed34e22a Mon Sep 17 00:00:00 2001
From: Jiang Liu <jiang.liu at linux.intel.com>
Date: Thu, 4 Jun 2015 16:41:44 +0800
Subject: 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 at linux.intel.com>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/virtio/virtio_pci_common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 9756f21..ea75707 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -415,6 +415,7 @@ 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);
 		}
--
1.9.1