From 09f628a0b49cf489faada00254569813a2143894 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 2 Mar 2020 15:56:48 -0800 Subject: [PATCH] KVM: x86: Fold CPUID 0x7 masking back into __do_cpuid_func() Move the CPUID 0x7 masking back into __do_cpuid_func() now that the size of the code has been trimmed down significantly. Tweak the WARN case, which is impossible to hit unless the CPU is completely broken, to break the loop before creating the bogus entry. Opportunustically reorder the cpuid_entry_set() calls and shorten the comment about emulation to further reduce the footprint of CPUID 0x7. Reviewed-by: Vitaly Kuznetsov Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 62 +++++++++++++++++++--------------------------------- 1 file changed, 22 insertions(+), 40 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index d012119..f6d3121 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -459,44 +459,6 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) return 0; } -static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry) -{ - switch (entry->index) { - case 0: - entry->eax = min(entry->eax, 1u); - cpuid_entry_mask(entry, CPUID_7_0_EBX); - /* TSC_ADJUST is emulated */ - cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST); - cpuid_entry_mask(entry, CPUID_7_ECX); - cpuid_entry_mask(entry, CPUID_7_EDX); - if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) - cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL); - if (boot_cpu_has(X86_FEATURE_STIBP)) - cpuid_entry_set(entry, X86_FEATURE_INTEL_STIBP); - if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) - cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL_SSBD); - /* - * We emulate ARCH_CAPABILITIES in software even - * if the host doesn't support it. - */ - cpuid_entry_set(entry, X86_FEATURE_ARCH_CAPABILITIES); - break; - case 1: - cpuid_entry_mask(entry, CPUID_7_1_EAX); - entry->ebx = 0; - entry->ecx = 0; - entry->edx = 0; - break; - default: - WARN_ON_ONCE(1); - entry->eax = 0; - entry->ebx = 0; - entry->ecx = 0; - entry->edx = 0; - break; - } -} - static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) { struct kvm_cpuid_entry2 *entry; @@ -558,14 +520,34 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) break; /* function 7 has additional index. */ case 7: - do_cpuid_7_mask(entry); + entry->eax = min(entry->eax, 1u); + cpuid_entry_mask(entry, CPUID_7_0_EBX); + cpuid_entry_mask(entry, CPUID_7_ECX); + cpuid_entry_mask(entry, CPUID_7_EDX); + + /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */ + cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST); + cpuid_entry_set(entry, X86_FEATURE_ARCH_CAPABILITIES); + + if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) + cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL); + if (boot_cpu_has(X86_FEATURE_STIBP)) + cpuid_entry_set(entry, X86_FEATURE_INTEL_STIBP); + if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) + cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL_SSBD); for (i = 1, max_idx = entry->eax; i <= max_idx; i++) { + if (WARN_ON_ONCE(i > 1)) + break; + entry = do_host_cpuid(array, function, i); if (!entry) goto out; - do_cpuid_7_mask(entry); + cpuid_entry_mask(entry, CPUID_7_1_EAX); + entry->ebx = 0; + entry->ecx = 0; + entry->edx = 0; } break; case 9: -- 2.7.4