When SVM is disabled by BIOS, one cannot use KVM but the
SVM feature is still shown in the output of /proc/cpuinfo.
On Intel machines, VMX is cleared by init_ia32_feat_ctl(),
so do the same on AMD and Hygon processors.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230921114940.957141-1-pbonzini@redhat.com
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
#define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE 0x1F
-/* AMD-V MSRs */
+/* AMD-V MSRs */
#define MSR_VM_CR 0xc0010114
#define MSR_VM_IGNNE 0xc0010115
#define MSR_VM_HSAVE_PA 0xc0010117
+#define SVM_VM_CR_VALID_MASK 0x001fULL
+#define SVM_VM_CR_SVM_LOCK_MASK 0x0008ULL
+#define SVM_VM_CR_SVM_DIS_MASK 0x0010ULL
+
/* Hardware Feedback Interface */
#define MSR_IA32_HW_FEEDBACK_PTR 0x17d0
#define MSR_IA32_HW_FEEDBACK_CONFIG 0x17d1
#define SVM_IOIO_SIZE_MASK (7 << SVM_IOIO_SIZE_SHIFT)
#define SVM_IOIO_ASIZE_MASK (7 << SVM_IOIO_ASIZE_SHIFT)
-#define SVM_VM_CR_VALID_MASK 0x001fULL
-#define SVM_VM_CR_SVM_LOCK_MASK 0x0008ULL
-#define SVM_VM_CR_SVM_DIS_MASK 0x0010ULL
-
#define SVM_NESTED_CTL_NP_ENABLE BIT(0)
#define SVM_NESTED_CTL_SEV_ENABLE BIT(1)
#define SVM_NESTED_CTL_SEV_ES_ENABLE BIT(2)
#define SVM_CPUID_FUNC 0x8000000a
-#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
static void init_amd(struct cpuinfo_x86 *c)
{
+ u64 vm_cr;
+
early_init_amd(c);
/*
init_amd_cacheinfo(c);
+ if (cpu_has(c, X86_FEATURE_SVM)) {
+ rdmsrl(MSR_VM_CR, vm_cr);
+ if (vm_cr & SVM_VM_CR_SVM_DIS_MASK) {
+ pr_notice_once("SVM disabled (by BIOS) in MSR_VM_CR\n");
+ clear_cpu_cap(c, X86_FEATURE_SVM);
+ }
+ }
+
if (!cpu_has(c, X86_FEATURE_LFENCE_RDTSC) && cpu_has(c, X86_FEATURE_XMM2)) {
/*
* Use LFENCE for execution serialization. On families which
static void init_hygon(struct cpuinfo_x86 *c)
{
+ u64 vm_cr;
+
early_init_hygon(c);
/*
init_hygon_cacheinfo(c);
+ if (cpu_has(c, X86_FEATURE_SVM)) {
+ rdmsrl(MSR_VM_CR, vm_cr);
+ if (vm_cr & SVM_VM_CR_SVM_DIS_MASK) {
+ pr_notice_once("SVM disabled (by BIOS) in MSR_VM_CR\n");
+ clear_cpu_cap(c, X86_FEATURE_SVM);
+ }
+ }
+
if (cpu_has(c, X86_FEATURE_XMM2)) {
/*
* Use LFENCE for execution serialization. On families which
int cpu = smp_processor_id();
struct cpuinfo_x86 *c = &cpu_data(cpu);
- u64 vm_cr;
-
if (c->x86_vendor != X86_VENDOR_AMD &&
c->x86_vendor != X86_VENDOR_HYGON) {
pr_err("CPU %d isn't AMD or Hygon\n", cpu);
return false;
}
- rdmsrl(MSR_VM_CR, vm_cr);
- if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) {
- pr_err("SVM disabled (by BIOS) in MSR_VM_CR on CPU %d\n", cpu);
- return false;
- }
-
return true;
}