x86/kvm: Add Hygon Dhyana support to KVM

The Hygon Dhyana CPU has the SVM feature as AMD family 17h does.
So enable the KVM infrastructure support to it.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/654dd12876149fba9561698eaf9fc15d030301f8.1537533369.git.puwen@hygon.cn

arch/x86/include/asm/kvm_emulate.h

@@ -364,6 +364,10 @@ struct x86_emulate_ctxt {
 #define X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx 0x21726574
 #define X86EMUL_CPUID_VENDOR_AMDisbetterI_edx 0x74656273
 
+#define X86EMUL_CPUID_VENDOR_HygonGenuine_ebx 0x6f677948
+#define X86EMUL_CPUID_VENDOR_HygonGenuine_ecx 0x656e6975
+#define X86EMUL_CPUID_VENDOR_HygonGenuine_edx 0x6e65476e
+
 #define X86EMUL_CPUID_VENDOR_GenuineIntel_ebx 0x756e6547
 #define X86EMUL_CPUID_VENDOR_GenuineIntel_ecx 0x6c65746e
 #define X86EMUL_CPUID_VENDOR_GenuineIntel_edx 0x49656e69

arch/x86/include/asm/virtext.h

@@ -83,9 +83,10 @@ static inline void cpu_emergency_vmxoff(void)
  */
 static inline int cpu_has_svm(const char **msg)
 {
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) {
 		if (msg)
-			*msg = "not amd";
+			*msg = "not amd or hygon";
 		return 0;
 	}
 

arch/x86/kvm/emulate.c

@@ -2711,7 +2711,16 @@ static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
 	    edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
 		return true;
 
-	/* default: (not Intel, not AMD), apply Intel's stricter rules... */
+	/* Hygon ("HygonGenuine") */
+	if (ebx == X86EMUL_CPUID_VENDOR_HygonGenuine_ebx &&
+	    ecx == X86EMUL_CPUID_VENDOR_HygonGenuine_ecx &&
+	    edx == X86EMUL_CPUID_VENDOR_HygonGenuine_edx)
+		return true;
+
+	/*
+	 * default: (not Intel, not AMD, not Hygon), apply Intel's
+	 * stricter rules...
+	 */
 	return false;
 }