From 6e7be6fc3eb45928bb28ebbedf30a30ed82b35b5 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 26 Mar 2013 13:41:35 +0000 Subject: [PATCH] ARM: KVM: arch_timers: zero CNTVOFF upon return to host commit f793c23ebbe5afd1cabf4a42a3a297022213756f upstream. To use the virtual counters from the host, we need to ensure that CNTVOFF doesn't change unexpectedly. When we change to a guest, we replace the host's CNTVOFF, but we don't restore it when returning to the host. As the host sets CNTVOFF to zero, and never changes it, we can simply zero CNTVOFF when returning to the host. This patch adds said zeroing to the return to host path. Signed-off-by: Mark Rutland Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar Acked-by: Christoffer Dall Cc: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/interrupts_head.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 2b44b95a86d..6f18695a09c 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -503,6 +503,10 @@ vcpu .req r0 @ vcpu pointer always in r0 add r5, vcpu, r4 strd r2, r3, [r5] + @ Ensure host CNTVCT == CNTPCT + mov r2, #0 + mcrr p15, 4, r2, r2, c14 @ CNTVOFF + 1: #endif @ Allow physical timer/counter access for the host -- 2.11.0