From c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 16 Sep 2015 16:18:59 +0100 Subject: [PATCH] arm64: KVM: Disable virtual timer even if the guest is not using it When running a guest with the architected timer disabled (with QEMU and the kernel_irqchip=off option, for example), it is important to make sure the timer gets turned off. Otherwise, the guest may try to enable it anyway, leading to a screaming HW interrupt. The fix is to unconditionally turn off the virtual timer on guest exit. Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 39aa322765f9..60a83e2900a7 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -562,8 +562,6 @@ mrs x3, cntv_ctl_el0 and x3, x3, #3 str w3, [x0, #VCPU_TIMER_CNTV_CTL] - bic x3, x3, #1 // Clear Enable - msr cntv_ctl_el0, x3 isb @@ -571,6 +569,9 @@ str x3, [x0, #VCPU_TIMER_CNTV_CVAL] 1: + // Disable the virtual timer + msr cntv_ctl_el0, xzr + // Allow physical timer/counter access for the host mrs x2, cnthctl_el2 orr x2, x2, #3 -- 2.20.1