From: Ignacio Alvarado <ikalvarado@google.com>
Date: Fri, 4 Nov 2016 19:15:55 +0000 (-0700)
Subject: KVM: Disable irq while unregistering user notifier
X-Git-Tag: v3.2.85~35
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=b2decb623a42f21e5fe878fe3f9e612e06b62106;hp=b2decb623a42f21e5fe878fe3f9e612e06b62106

KVM: Disable irq while unregistering user notifier

commit 1650b4ebc99da4c137bfbfc531be4a2405f951dd upstream.

Function user_notifier_unregister should be called only once for each
registered user notifier.

Function kvm_arch_hardware_disable can be executed from an IPI context
which could cause a race condition with a VCPU returning to user mode
and attempting to unregister the notifier.

Signed-off-by: Ignacio Alvarado <ikalvarado@google.com>
Fixes: 18863bdd60f8 ("KVM: x86 shared msr infrastructure")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---