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authorRadim Krčmář <rkrcmar@redhat.com>2015-07-01 15:31:49 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2015-07-03 18:55:17 +0200
commit42720138b06301cc8a7ee8a495a6d021c4b6a9bc (patch)
treefbffa8a4feceef419b8d1f56cd521148095a8ba5 /arch/x86/kvm/i8254.c
parent2ecd9d29abb171d6e97a4f3eb29d7456a11401b7 (diff)
KVM: x86: make vapics_in_nmi_mode atomic
Writes were a bit racy, but hard to turn into a bug at the same time. (Particularly because modern Linux doesn't use this feature anymore.) Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [Actually the next patch makes it much, much easier to trigger the race so I'm including this one for stable@ as well. - Paolo] Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/i8254.c')
-rw-r--r--arch/x86/kvm/i8254.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 4dce6f8b6129..f90952f64e79 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -305,7 +305,7 @@ static void pit_do_work(struct kthread_work *work)
* LVT0 to NMI delivery. Other PIC interrupts are just sent to
* VCPU0, and only if its LVT0 is in EXTINT mode.
*/
- if (kvm->arch.vapics_in_nmi_mode > 0)
+ if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0)
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_apic_nmi_wd_deliver(vcpu);
}