From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757190AbXGHL6U (ORCPT ); Sun, 8 Jul 2007 07:58:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753817AbXGHLzS (ORCPT ); Sun, 8 Jul 2007 07:55:18 -0400 Received: from il.qumranet.com ([82.166.9.18]:38406 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbXGHLyq (ORCPT ); Sun, 8 Jul 2007 07:54:46 -0400 From: Avi Kivity To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, Joerg Roedel , Avi Kivity Subject: [PATCH 11/20] KVM: SVM: Reliably detect if SVM was disabled by BIOS Date: Sun, 8 Jul 2007 14:54:40 +0300 Message-Id: <11838956892580-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.2.2 In-Reply-To: <11838956891287-git-send-email-avi@qumranet.com> References: <11838956891287-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel 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 --- 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 62ec38c..a0d4428 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -1735,6 +1735,12 @@ 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 5e93814..3b1b0f3 100644 --- a/drivers/kvm/svm.h +++ b/drivers/kvm/svm.h @@ -175,8 +175,11 @@ 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 -- 1.5.2.2