From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57807 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933161AbbIZVHq (ORCPT ); Sat, 26 Sep 2015 17:07:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoffer Dall , Marc Zyngier Subject: [PATCH 4.1 025/159] arm64: KVM: Disable virtual timer even if the guest is not using it Date: Sat, 26 Sep 2015 13:54:31 -0700 Message-Id: <20150926205314.943574594@linuxfoundation.org> In-Reply-To: <20150926205313.363686083@linuxfoundation.org> References: <20150926205313.363686083@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org List-ID: 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 upstream. 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. Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kvm/hyp.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -844,8 +844,6 @@ 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 @@ -853,6 +851,9 @@ 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