Commit 46505c0f authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: x86: Handle kernel- and KVM-defined CPUID words in a single helper 

Merge kvm_cpu_cap_init() and kvm_cpu_cap_init_kvm_defined() into a single
helper.  The only advantage of separating the two was to make it somewhat
obvious that KVM directly initializes the KVM-defined words, whereas using
a common helper will allow for hardening both kernel- and KVM-defined
CPUID words without needing copy+paste.

No functional change intended.

Link: https://lore.kernel.org/r/20241128013424.4096668-27-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 264969b4

arch/x86/kvm/cpuid.c

+16 −30
Original line number Diff line number Diff line
@@ -623,35 +623,21 @@ static __always_inline u32 raw_cpuid_get(struct cpuid_reg cpuid) 
	return *__cpuid_entry_get_reg(&entry, cpuid.reg);

}



/* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */

static __always_inline void __kvm_cpu_cap_mask(unsigned int leaf)

static __always_inline void kvm_cpu_cap_init(u32 leaf, u32 mask)

{

	const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32);



	reverse_cpuid_check(leaf);



	kvm_cpu_caps[leaf] &= raw_cpuid_get(cpuid);

}



static __always_inline

void kvm_cpu_cap_init_kvm_defined(enum kvm_only_cpuid_leafs leaf, u32 mask)

{

	/* Use kvm_cpu_cap_init for leafs that aren't KVM-only. */

	BUILD_BUG_ON(leaf < NCAPINTS);



	kvm_cpu_caps[leaf] = mask;



	__kvm_cpu_cap_mask(leaf);

}



static __always_inline void kvm_cpu_cap_init(enum cpuid_leafs leaf, u32 mask)

{

	/* Use kvm_cpu_cap_init_kvm_defined for KVM-only leafs. */

	BUILD_BUG_ON(leaf >= NCAPINTS);



	/*

	 * For kernel-defined leafs, mask the boot CPU's pre-populated value.

	 * For KVM-defined leafs, explicitly set the leaf, as KVM is the one

	 * and only authority.

	 */

	if (leaf < NCAPINTS)

		kvm_cpu_caps[leaf] &= mask;

	else

		kvm_cpu_caps[leaf] = mask;



	__kvm_cpu_cap_mask(leaf);

	kvm_cpu_caps[leaf] &= raw_cpuid_get(cpuid);

}



#define F feature_bit
@@ -864,7 +850,7 @@ void kvm_set_cpu_caps(void) 
		F(LAM)

	);



	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,

	kvm_cpu_cap_init(CPUID_7_1_EDX,

		F(AVX_VNNI_INT8) |

		F(AVX_NE_CONVERT) |

		F(AMX_COMPLEX) |
@@ -873,7 +859,7 @@ void kvm_set_cpu_caps(void) 
		F(AVX10)

	);



	kvm_cpu_cap_init_kvm_defined(CPUID_7_2_EDX,

	kvm_cpu_cap_init(CPUID_7_2_EDX,

		F(INTEL_PSFD) |

		F(IPRED_CTRL) |

		F(RRSBA_CTRL) |
@@ -890,13 +876,13 @@ void kvm_set_cpu_caps(void) 
		X86_64_F(XFD)

	);



	kvm_cpu_cap_init_kvm_defined(CPUID_12_EAX,

	kvm_cpu_cap_init(CPUID_12_EAX,

		SF(SGX1) |

		SF(SGX2) |

		SF(SGX_EDECCSSA)

	);



	kvm_cpu_cap_init_kvm_defined(CPUID_24_0_EBX,

	kvm_cpu_cap_init(CPUID_24_0_EBX,

		F(AVX10_128) |

		F(AVX10_256) |

		F(AVX10_512)
@@ -959,7 +945,7 @@ void kvm_set_cpu_caps(void) 
	if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64))

		kvm_cpu_cap_set(X86_FEATURE_GBPAGES);



	kvm_cpu_cap_init_kvm_defined(CPUID_8000_0007_EDX,

	kvm_cpu_cap_init(CPUID_8000_0007_EDX,

		SF(CONSTANT_TSC)

	);
@@ -1033,7 +1019,7 @@ void kvm_set_cpu_caps(void) 
	kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE);

	kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO);



	kvm_cpu_cap_init_kvm_defined(CPUID_8000_0022_EAX,

	kvm_cpu_cap_init(CPUID_8000_0022_EAX,

		F(PERFMON_V2)

	);