KVM: x86: Enable Intel AVX-512 for guest

Expose Intel AVX-512 feature bits to guest. Also add checks for
xcr0 AVX512 related bits according to spec:
http://download-software.intel.com/sites/default/files/managed/71/2e/319433-017.pdfSigned-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/xsave.h

@@ -16,6 +16,7 @@
 #define XSTATE_Hi16_ZMM		0x80
 
 #define XSTATE_FPSSE	(XSTATE_FP | XSTATE_SSE)
+#define XSTATE_AVX512	(XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
 /* Bit 63 of XCR0 is reserved for future expansion */
 #define XSTATE_EXTEND_MASK	(~(XSTATE_FPSSE | (1ULL << 63)))
 

arch/x86/kvm/cpuid.c

@@ -317,7 +317,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	const u32 kvm_supported_word9_x86_features =
 		F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
 		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
-		F(ADX) | F(SMAP);
+		F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
+		F(AVX512CD);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
 	get_cpu();

arch/x86/kvm/x86.c

@@ -666,6 +666,12 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 	if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR)))
 		return 1;
 
+	if (xcr0 & XSTATE_AVX512) {
+		if (!(xcr0 & XSTATE_YMM))
+			return 1;
+		if ((xcr0 & XSTATE_AVX512) != XSTATE_AVX512)
+			return 1;
+	}
 	kvm_put_guest_xcr0(vcpu);
 	vcpu->arch.xcr0 = xcr0;
 

arch/x86/kvm/x86.h

@@ -162,7 +162,8 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
 bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data);
 
 #define KVM_SUPPORTED_XCR0     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM \
-				| XSTATE_BNDREGS | XSTATE_BNDCSR)
+				| XSTATE_BNDREGS | XSTATE_BNDCSR \
+				| XSTATE_AVX512)
 extern u64 host_xcr0;
 
 extern u64 kvm_supported_xcr0(void);