KVM: x86 emulator: change ->get_cpuid() accessor to use the x86 semantics
Instead of getting an exact leaf, follow the spec and fall back to the last
main leaf instead. This lets us easily emulate the cpuid instruction in the
emulator.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index f95d242..ba1f8ec 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1993,8 +1993,8 @@
u32 eax, ebx, ecx, edx;
eax = ecx = 0;
- return ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)
- && ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
+ ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
+ return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
&& ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
&& edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
}
@@ -2013,32 +2013,31 @@
eax = 0x00000000;
ecx = 0x00000000;
- if (ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)) {
- /*
- * Intel ("GenuineIntel")
- * remark: Intel CPUs only support "syscall" in 64bit
- * longmode. Also an 64bit guest with a
- * 32bit compat-app running will #UD !! While this
- * behaviour can be fixed (by emulating) into AMD
- * response - CPUs of AMD can't behave like Intel.
- */
- if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
- ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
- edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
- return false;
+ ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
+ /*
+ * Intel ("GenuineIntel")
+ * remark: Intel CPUs only support "syscall" in 64bit
+ * longmode. Also an 64bit guest with a
+ * 32bit compat-app running will #UD !! While this
+ * behaviour can be fixed (by emulating) into AMD
+ * response - CPUs of AMD can't behave like Intel.
+ */
+ if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
+ ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
+ edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
+ return false;
- /* AMD ("AuthenticAMD") */
- if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
- ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
- edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
- return true;
+ /* AMD ("AuthenticAMD") */
+ if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
+ ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
+ edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
+ return true;
- /* AMD ("AMDisbetter!") */
- if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
- ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
- edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
- return true;
- }
+ /* AMD ("AMDisbetter!") */
+ if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
+ ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
+ edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
+ return true;
/* default: (not Intel, not AMD), apply Intel's stricter rules... */
return false;