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authorYu Zhang <yu.c.zhang@linux.intel.com>2017-08-24 15:27:52 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2017-08-24 19:09:15 +0300
commite911eb3b3414e62cbd9853e0a91c124f4a545c0f (patch)
treee8ac1e3c35b9d452ef099cd3b04f2c1f40fe5c25 /arch/x86/kvm/cpuid.c
parent3db134805c69aae16ba6193946aa8deccd393ead (diff)
downloadlinux-e911eb3b3414e62cbd9853e0a91c124f4a545c0f.tar.xz
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.c17
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);