VM Guests may want to use Auto IBRS, so propagate the CPUID to them.
Co-developed-by: Babu Moger <Babu.Moger@xxxxxxx>
Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx>
---
arch/x86/kvm/cpuid.c | 5 ++++-
arch/x86/kvm/reverse_cpuid.h | 1 +
arch/x86/kvm/svm/svm.c | 3 +++
arch/x86/kvm/x86.c | 3 +++
4 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7065462378e2..2524cd82627b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -730,6 +730,8 @@ void kvm_set_cpu_caps(void)
0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) |
F(SME_COHERENT));
+ kvm_cpu_cap_mask(CPUID_8000_0021_EAX, F(AUTOIBRS));
+
kvm_cpu_cap_mask(CPUID_C000_0001_EDX,
F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
@@ -1211,12 +1213,13 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
* EAX 0 NNDBP, Processor ignores nested data breakpoints
* EAX 2 LAS, LFENCE always serializing
* EAX 6 NSCB, Null selector clear base
+ * EAX 8 Automatic IBRS
*
* Other defined bits are for MSRs that KVM does not expose:
* EAX 3 SPCL, SMM page configuration lock
* EAX 13 PCMSR, Prefetch control MSR
*/
- entry->eax &= BIT(0) | BIT(2) | BIT(6);
+ entry->eax &= BIT(0) | BIT(2) | BIT(6) | BIT(8);
if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC))
entry->eax |= BIT(2);
if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index a19d473d0184..7eeade35a425 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -48,6 +48,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
[CPUID_7_1_EAX] = { 7, 1, CPUID_EAX},
[CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX},
[CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
+ [CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
};
/*
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 58f0077d9357..2add5eb3303f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4993,6 +4993,9 @@ static __init int svm_hardware_setup(void)
tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX);
+ if (boot_cpu_has(X86_FEATURE_AUTOIBRS))
+ kvm_enable_efer_bits(EFER_AUTOIBRS);
+
/* Check for pause filtering support */
if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {
pause_filter_count = 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9cf1ba865562..3dbeda353853 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1687,6 +1687,9 @@ static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
static bool __kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
+ if (efer & EFER_AUTOIBRS && !guest_cpuid_has(vcpu, X86_FEATURE_AUTOIBRS))
+ return false;
+
if (efer & EFER_FFXSR && !guest_cpuid_has(vcpu, X86_FEATURE_FXSR_OPT))
return false;
--
2.34.1
