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| author | Yu Zhang <yu.c.zhang@linux.intel.com> | 2017-08-24 20:27:52 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-08-24 18:09:15 +0200 |
| commit | e911eb3b3414e62cbd9853e0a91c124f4a545c0f (patch) | |
| tree | e8ac1e3c35b9d452ef099cd3b04f2c1f40fe5c25 /arch/x86/kvm/cpuid.c | |
| parent | 3db134805c69aae16ba6193946aa8deccd393ead (diff) | |
| download | lwn-e911eb3b3414e62cbd9853e0a91c124f4a545c0f.tar.gz lwn-e911eb3b3414e62cbd9853e0a91c124f4a545c0f.zip | |
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 <yu.c.zhang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 17 |
1 files changed, 13 insertions, 4 deletions
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); |