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authorJoerg Roedel <joerg.roedel@amd.com>2007-06-22 12:29:50 +0300
committerAvi Kivity <avi@qumranet.com>2007-07-16 12:05:49 +0300
commit6031a61c2ef4cf22b69ef5494aefa54b84a27d2f (patch)
tree2e0ccd861da726e76785a0a68a46da06951f1eb0
parent796fd1b23e463e98b3e2fc86ed571db06dc945bb (diff)
KVM: SVM: Reliably detect if SVM was disabled by BIOS
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 <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
-rw-r--r--drivers/kvm/svm.c6
-rw-r--r--drivers/kvm/svm.h3
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 62ec38c7027..a0d442883e1 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 5e93814400c..3b1b0f35b6c 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