From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Joerg Roedel" Subject: [PATCH] SVM: reliably detect if SVM was disabled by BIOS Date: Thu, 21 Jun 2007 19:51:22 +0200 Message-ID: <20070621175122.GE25896@amd.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary=z6Eq5LdranGa6ru8 Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Avi Kivity" Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org --z6Eq5LdranGa6ru8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 7bit 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 -- | AMD Saxony Limited Liability Company & Co. KG Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany System | Register Court Dresden: HRA 4896 Research | General Partner authorized to represent: Center | AMD Saxony LLC (Wilmington, Delaware, US) | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy --z6Eq5LdranGa6ru8 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=svm-detect-svm-disable.patch Content-Transfer-Encoding: 7bit diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index fa17d6d..54aa83a 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -1727,6 +1727,12 @@ static void svm_inject_page_fault(struct kvm_vcpu *vcpu, static int is_disabled(void) { + uint64_t 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..005a9c5 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 0xc0010114ULL #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 --z6Eq5LdranGa6ru8 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ --z6Eq5LdranGa6ru8 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ kvm-devel mailing list kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org https://lists.sourceforge.net/lists/listinfo/kvm-devel --z6Eq5LdranGa6ru8--