lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

KVM: SVM: Reliably detect if SVM was disabled by BIOS

Browse Source 
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>
This commit is contained in:
Joerg Roedel
2007-06-22 12:29:50 +03:00
committed by Avi Kivity
parent 796fd1b23e
commit 6031a61c2e
2 changed files with 9 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/kvm/svm.c
View File

@@ -1735,6 +1735,12 @@ static void svm_inject_page_fault(struct kvm_vcpu *vcpu,
static int is_disabled(void) 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; return 0;
} }

3
drivers/kvm/svm.h
View File

@@ -175,8 +175,11 @@ struct __attribute__ ((__packed__)) vmcb {
#define SVM_CPUID_FUNC 0x8000000a #define SVM_CPUID_FUNC 0x8000000a
#define MSR_EFER_SVME_MASK (1ULL << 12) #define MSR_EFER_SVME_MASK (1ULL << 12)
#define MSR_VM_CR 0xc0010114
#define MSR_VM_HSAVE_PA 0xc0010117ULL #define MSR_VM_HSAVE_PA 0xc0010117ULL
#define SVM_VM_CR_SVM_DISABLE 4
#define SVM_SELECTOR_S_SHIFT 4 #define SVM_SELECTOR_S_SHIFT 4
#define SVM_SELECTOR_DPL_SHIFT 5 #define SVM_SELECTOR_DPL_SHIFT 5
#define SVM_SELECTOR_P_SHIFT 7 #define SVM_SELECTOR_P_SHIFT 7