From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759303AbXHVI4P (ORCPT ); Wed, 22 Aug 2007 04:56:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751221AbXHVIwr (ORCPT ); Wed, 22 Aug 2007 04:52:47 -0400 Received: from 1wt.eu ([62.212.114.60]:1932 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757950AbXHVIwp (ORCPT ); Wed, 22 Aug 2007 04:52:45 -0400 From: Willy Tarreau Message-Id: <20070822083950.%N@1wt.eu> References: <20070822083844.%N@1wt.eu> User-Agent: quilt/0.46-1 Date: Wed, 22 Aug 2007 11:38:57 +0200 To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Joerg Roedel , Avi Kivity , Greg Kroah-Hartman , Willy Tarreau Subject: [2.6.20.17 review 13/58] KVM: SVM: Reliably detect if SVM was disabled by BIOS Content-Disposition: inline; filename=0013-KVM-SVM-Reliably-detect-if-SVM-was-disabled-by-BIO.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This patch adds an implementation to the svm is_disabled function to detect reliably if the BIOS disabled the SVM feature in the CPU. This fixes the issues with kernel panics when loading the kvm-amd module on machines where SVM is available but disabled. Signed-off-by: Joerg Roedel Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/kvm/svm.c | 6 ++++++ drivers/kvm/svm.h | 3 +++ 2 files changed, 9 insertions(+), 0 deletions(-) diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index c79df79..1e90401 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -1655,6 +1655,12 @@ static void svm_inject_page_fault(struct kvm_vcpu *vcpu, static int is_disabled(void) { + u64 vm_cr; + + rdmsrl(MSR_VM_CR, vm_cr); + if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) + return 1; + return 0; } diff --git a/drivers/kvm/svm.h b/drivers/kvm/svm.h index df731c3..e8f0349 100644 --- a/drivers/kvm/svm.h +++ b/drivers/kvm/svm.h @@ -172,8 +172,11 @@ struct __attribute__ ((__packed__)) vmcb { #define SVM_CPUID_FUNC 0x8000000a #define MSR_EFER_SVME_MASK (1ULL << 12) +#define MSR_VM_CR 0xc0010114 #define MSR_VM_HSAVE_PA 0xc0010117ULL +#define SVM_VM_CR_SVM_DISABLE 4 + #define SVM_SELECTOR_S_SHIFT 4 #define SVM_SELECTOR_DPL_SHIFT 5 #define SVM_SELECTOR_P_SHIFT 7 -- 1.5.2.5 --