Commit 8c19b6f2 authored Jan 24, 2023 by Kim Phillips Committed by Borislav Petkov (AMD) Jan 25, 2023

KVM: x86: Propagate the AMD Automatic IBRS feature to the guest



Add the AMD Automatic IBRS feature bit to those being propagated to the guest,
and enable the guest EFER bit.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-9-kim.phillips@amd.com

parent e7862eda

arch/x86/kvm/cpuid.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -743,7 +743,7 @@ void kvm_set_cpu_caps(void)

	kvm_cpu_cap_mask(CPUID_8000_0021_EAX,		kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
	F(NO_NESTED_DATA_BP) \| F(LFENCE_RDTSC) \| 0 /* SmmPgCfgLock */ \|		F(NO_NESTED_DATA_BP) \| F(LFENCE_RDTSC) \| 0 /* SmmPgCfgLock */ \|
	F(NULL_SEL_CLR_BASE) \| 0 /* PrefetchCtlMsr */		F(NULL_SEL_CLR_BASE) \| F(AUTOIBRS) \| 0 /* PrefetchCtlMsr */
	);		);

	/*		/*

arch/x86/kvm/svm/svm.c

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -4969,6 +4969,9 @@ static __init int svm_hardware_setup(void)

	tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX);		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 */		/* Check for pause filtering support */
	if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {		if (!boot_cpu_has(X86_FEATURE_PAUSEFILTER)) {
	pause_filter_count = 0;		pause_filter_count = 0;

arch/x86/kvm/x86.c

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1685,6 +1685,9 @@ 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)		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))		if (efer & EFER_FFXSR && !guest_cpuid_has(vcpu, X86_FEATURE_FXSR_OPT))
	return false;		return false;