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Merge tag 'x86_cpu_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov: - Make sure the "svm" feature flag is cleared from /proc/cpuinfo when virtualization support is disabled in the BIOS on AMD and Hygon platforms - A minor cleanup * tag 'x86_cpu_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Remove redundant 'break' statement x86/cpu: Clear SVM feature if disabled by BIOS
2 parents 9ab021a + b5034c6 commit ca2e9c3

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5 files changed

+25
-16
lines changed

5 files changed

+25
-16
lines changed

arch/x86/include/asm/msr-index.h

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1117,12 +1117,16 @@
11171117
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
11181118
#define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
11191119
#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE 0x1F
1120-
/* AMD-V MSRs */
11211120

1121+
/* AMD-V MSRs */
11221122
#define MSR_VM_CR 0xc0010114
11231123
#define MSR_VM_IGNNE 0xc0010115
11241124
#define MSR_VM_HSAVE_PA 0xc0010117
11251125

1126+
#define SVM_VM_CR_VALID_MASK 0x001fULL
1127+
#define SVM_VM_CR_SVM_LOCK_MASK 0x0008ULL
1128+
#define SVM_VM_CR_SVM_DIS_MASK 0x0010ULL
1129+
11261130
/* Hardware Feedback Interface */
11271131
#define MSR_IA32_HW_FEEDBACK_PTR 0x17d0
11281132
#define MSR_IA32_HW_FEEDBACK_CONFIG 0x17d1

arch/x86/include/asm/svm.h

Lines changed: 0 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -229,10 +229,6 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
229229
#define SVM_IOIO_SIZE_MASK (7 << SVM_IOIO_SIZE_SHIFT)
230230
#define SVM_IOIO_ASIZE_MASK (7 << SVM_IOIO_ASIZE_SHIFT)
231231

232-
#define SVM_VM_CR_VALID_MASK 0x001fULL
233-
#define SVM_VM_CR_SVM_LOCK_MASK 0x0008ULL
234-
#define SVM_VM_CR_SVM_DIS_MASK 0x0010ULL
235-
236232
#define SVM_NESTED_CTL_NP_ENABLE BIT(0)
237233
#define SVM_NESTED_CTL_SEV_ENABLE BIT(1)
238234
#define SVM_NESTED_CTL_SEV_ES_ENABLE BIT(2)
@@ -572,8 +568,6 @@ struct vmcb {
572568

573569
#define SVM_CPUID_FUNC 0x8000000a
574570

575-
#define SVM_VM_CR_SVM_DISABLE 4
576-
577571
#define SVM_SELECTOR_S_SHIFT 4
578572
#define SVM_SELECTOR_DPL_SHIFT 5
579573
#define SVM_SELECTOR_P_SHIFT 7

arch/x86/kernel/cpu/amd.c

Lines changed: 10 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1014,7 +1014,6 @@ static bool cpu_has_zenbleed_microcode(void)
10141014

10151015
default:
10161016
return false;
1017-
break;
10181017
}
10191018

10201019
if (boot_cpu_data.microcode < good_rev)
@@ -1044,6 +1043,8 @@ static void zenbleed_check(struct cpuinfo_x86 *c)
10441043

10451044
static void init_amd(struct cpuinfo_x86 *c)
10461045
{
1046+
u64 vm_cr;
1047+
10471048
early_init_amd(c);
10481049

10491050
/*
@@ -1095,6 +1096,14 @@ static void init_amd(struct cpuinfo_x86 *c)
10951096

10961097
init_amd_cacheinfo(c);
10971098

1099+
if (cpu_has(c, X86_FEATURE_SVM)) {
1100+
rdmsrl(MSR_VM_CR, vm_cr);
1101+
if (vm_cr & SVM_VM_CR_SVM_DIS_MASK) {
1102+
pr_notice_once("SVM disabled (by BIOS) in MSR_VM_CR\n");
1103+
clear_cpu_cap(c, X86_FEATURE_SVM);
1104+
}
1105+
}
1106+
10981107
if (!cpu_has(c, X86_FEATURE_LFENCE_RDTSC) && cpu_has(c, X86_FEATURE_XMM2)) {
10991108
/*
11001109
* Use LFENCE for execution serialization. On families which

arch/x86/kernel/cpu/hygon.c

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -290,6 +290,8 @@ static void early_init_hygon(struct cpuinfo_x86 *c)
290290

291291
static void init_hygon(struct cpuinfo_x86 *c)
292292
{
293+
u64 vm_cr;
294+
293295
early_init_hygon(c);
294296

295297
/*
@@ -320,6 +322,14 @@ static void init_hygon(struct cpuinfo_x86 *c)
320322

321323
init_hygon_cacheinfo(c);
322324

325+
if (cpu_has(c, X86_FEATURE_SVM)) {
326+
rdmsrl(MSR_VM_CR, vm_cr);
327+
if (vm_cr & SVM_VM_CR_SVM_DIS_MASK) {
328+
pr_notice_once("SVM disabled (by BIOS) in MSR_VM_CR\n");
329+
clear_cpu_cap(c, X86_FEATURE_SVM);
330+
}
331+
}
332+
323333
if (cpu_has(c, X86_FEATURE_XMM2)) {
324334
/*
325335
* Use LFENCE for execution serialization. On families which

arch/x86/kvm/svm/svm.c

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -531,8 +531,6 @@ static bool __kvm_is_svm_supported(void)
531531
int cpu = smp_processor_id();
532532
struct cpuinfo_x86 *c = &cpu_data(cpu);
533533

534-
u64 vm_cr;
535-
536534
if (c->x86_vendor != X86_VENDOR_AMD &&
537535
c->x86_vendor != X86_VENDOR_HYGON) {
538536
pr_err("CPU %d isn't AMD or Hygon\n", cpu);
@@ -549,12 +547,6 @@ static bool __kvm_is_svm_supported(void)
549547
return false;
550548
}
551549

552-
rdmsrl(MSR_VM_CR, vm_cr);
553-
if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) {
554-
pr_err("SVM disabled (by BIOS) in MSR_VM_CR on CPU %d\n", cpu);
555-
return false;
556-
}
557-
558550
return true;
559551
}
560552

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