From e911eb3b3414e62cbd9853e0a91c124f4a545c0f Mon Sep 17 00:00:00 2001 From: Yu Zhang Date: Thu, 24 Aug 2017 20:27:52 +0800 Subject: KVM: x86: Add return value to kvm_cpuid(). Return false in kvm_cpuid() when it fails to find the cpuid entry. Also, this routine(and its caller) is optimized with a new argument - check_limit, so that the check_cpuid_limit() fall back can be avoided. Signed-off-by: Yu Zhang Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 59ca2eea522c..14505473fb21 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -853,16 +853,24 @@ static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); } -void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool check_limit) { u32 function = *eax, index = *ecx; struct kvm_cpuid_entry2 *best; + bool entry_found = true; best = kvm_find_cpuid_entry(vcpu, function, index); - if (!best) + if (!best) { + entry_found = false; + if (!check_limit) + goto out; + best = check_cpuid_limit(vcpu, function, index); + } +out: if (best) { *eax = best->eax; *ebx = best->ebx; @@ -870,7 +878,8 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) *edx = best->edx; } else *eax = *ebx = *ecx = *edx = 0; - trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); + trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); + return entry_found; } EXPORT_SYMBOL_GPL(kvm_cpuid); @@ -883,7 +892,7 @@ int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) eax = kvm_register_read(vcpu, VCPU_REGS_RAX); ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); - kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); + kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); kvm_register_write(vcpu, VCPU_REGS_RAX, eax); kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); -- cgit v1.2.3