Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631AbbLNPOE (ORCPT ); Mon, 14 Dec 2015 10:14:04 -0500 Received: from mga04.intel.com ([192.55.52.120]:32322 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528AbbLNPNy (ORCPT ); Mon, 14 Dec 2015 10:13:54 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,427,1444719600"; d="scan'208";a="873289246" From: Haozhong Zhang To: kvm@vger.kernel.org Cc: Paolo Bonzini , Gleb Natapov , x86@kernel.org, linux-kernel@vger.kernel.org, Haozhong Zhang Subject: [PATCH] KVM: VMX: Fix host initiated access to guest MSR_TSC_AUX Date: Mon, 14 Dec 2015 23:13:38 +0800 Message-Id: <1450106018-7824-1-git-send-email-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.4.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1545 Lines: 41 The current handling of accesses to guest MSR_TSC_AUX returns error if vcpu does not support rdtscp, though those accesses are initiated by host. This can result in the reboot failure of some versions of QEMU. This patch fixes this issue by passing those host initiated accesses for further handling instead. Signed-off-by: Haozhong Zhang --- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 1a8bfaa..50f2b78 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2802,7 +2802,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vcpu->arch.ia32_xss; break; case MSR_TSC_AUX: - if (!guest_cpuid_has_rdtscp(vcpu)) + if (!guest_cpuid_has_rdtscp(vcpu) && !msr_info->host_initiated) return 1; /* Otherwise falls through */ default: @@ -2908,7 +2908,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) clear_atomic_switch_msr(vmx, MSR_IA32_XSS); break; case MSR_TSC_AUX: - if (!guest_cpuid_has_rdtscp(vcpu)) + if (!guest_cpuid_has_rdtscp(vcpu) && !msr_info->host_initiated) return 1; /* Check reserved bit, higher 32 bits should be zero */ if ((data >> 32) != 0) -- 2.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/