From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754637AbbJ0WGa (ORCPT ); Tue, 27 Oct 2015 18:06:30 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34905 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932135AbbJ0Va7 (ORCPT ); Tue, 27 Oct 2015 17:30:59 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Marc Zyngier , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 39/86] arm64: KVM: Disable virtual timer even if the guest is not using it Date: Tue, 27 Oct 2015 14:29:39 -0700 Message-Id: <1445981426-19727-40-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445981426-19727-1-git-send-email-kamal@canonical.com> References: <1445981426-19727-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt9 -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: Kamal Mostafa --- 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 cbaa8bc..0a2ff0f 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -843,8 +843,6 @@ 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 @@ -852,6 +850,9 @@ 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 -- 1.9.1