x86emul: support of AVX512_IFMA insns

Once again take the liberty and also correct the (public interface) name
of the AVX512_IFMA feature flag to match the SDM, on the assumption that
no external consumer has actually been using that flag so far.

As in a few cases before, since the insns here and in particular their
memory access patterns follow the usual scheme, I didn't think it was
necessary to add a contrived test specifically for them, beyond the
Disp8 scaling one.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

tools/tests/x86_emulator/evex-disp8.c

@@ -543,6 +543,11 @@ static const struct test avx512_bitalg_all[] = {
     INSN(pshufbitqmb, 66, 0f38, 8f, vl,  b, vl),
 };
 
+static const struct test avx512_ifma_all[] = {
+    INSN(pmadd52huq, 66, 0f38, b5, vl, q, vl),
+    INSN(pmadd52luq, 66, 0f38, b4, vl, q, vl),
+};
+
 static const struct test avx512_vbmi_all[] = {
     INSN(permb,         66, 0f38, 8d, vl, b, vl),
     INSN(permi2b,       66, 0f38, 75, vl, b, vl),
@@ -929,6 +934,7 @@ void evex_disp8_test(void *instr, struct x86_emulate_ctxt *ctxt,
 #define cpu_has_avx512pf cpu_has_avx512f
     RUN(avx512pf, 512);
     RUN(avx512_bitalg, all);
+    RUN(avx512_ifma, all);
     RUN(avx512_vbmi, all);
     RUN(avx512_vbmi2, all);
     RUN(avx512_vpopcntdq, all);

tools/tests/x86_emulator/x86-emulate.h

@@ -137,6 +137,7 @@ static inline bool xcr0_mask(uint64_t mask)
 #define cpu_has_bmi2       cp.feat.bmi2
 #define cpu_has_avx512f   (cp.feat.avx512f  && xcr0_mask(0xe6))
 #define cpu_has_avx512dq  (cp.feat.avx512dq && xcr0_mask(0xe6))
+#define cpu_has_avx512_ifma (cp.feat.avx512_ifma && xcr0_mask(0xe6))
 #define cpu_has_avx512er  (cp.feat.avx512er && xcr0_mask(0xe6))
 #define cpu_has_avx512cd  (cp.feat.avx512cd && xcr0_mask(0xe6))
 #define cpu_has_avx512bw  (cp.feat.avx512bw && xcr0_mask(0xe6))

xen/arch/x86/x86_emulate/x86_emulate.c

@@ -521,6 +521,7 @@ static const struct ext0f38_table {
     [0xad] = { .simd_size = simd_scalar_vexw, .d8s = d8s_dq },
     [0xae] = { .simd_size = simd_packed_fp, .d8s = d8s_vl },
     [0xaf] = { .simd_size = simd_scalar_vexw, .d8s = d8s_dq },
+    [0xb4 ... 0xb5] = { .simd_size = simd_packed_int, .d8s = d8s_vl },
     [0xb6 ... 0xb8] = { .simd_size = simd_packed_fp, .d8s = d8s_vl },
     [0xb9] = { .simd_size = simd_scalar_vexw, .d8s = d8s_dq },
     [0xba] = { .simd_size = simd_packed_fp, .d8s = d8s_vl },
@@ -1875,6 +1876,7 @@ in_protmode(
 #define vcpu_has_rdseed()      (ctxt->cpuid->feat.rdseed)
 #define vcpu_has_adx()         (ctxt->cpuid->feat.adx)
 #define vcpu_has_smap()        (ctxt->cpuid->feat.smap)
+#define vcpu_has_avx512_ifma() (ctxt->cpuid->feat.avx512_ifma)
 #define vcpu_has_clflushopt()  (ctxt->cpuid->feat.clflushopt)
 #define vcpu_has_clwb()        (ctxt->cpuid->feat.clwb)
 #define vcpu_has_avx512pf()    (ctxt->cpuid->feat.avx512pf)
@@ -9455,6 +9457,12 @@ x86_emulate(
         break;
     }
 
+    case X86EMUL_OPC_EVEX_66(0x0f38, 0xb4): /* vpmadd52luq [xyz]mm/mem,[xyz]mm,[xyz]mm{k} */
+    case X86EMUL_OPC_EVEX_66(0x0f38, 0xb5): /* vpmadd52huq [xyz]mm/mem,[xyz]mm,[xyz]mm{k} */
+        host_and_vcpu_must_have(avx512_ifma);
+        generate_exception_if(!evex.w, EXC_UD);
+        goto avx512f_no_sae;
+
     case X86EMUL_OPC_EVEX_66(0x0f38, 0xc6):
     case X86EMUL_OPC_EVEX_66(0x0f38, 0xc7):
     {

xen/include/asm-x86/cpufeature.h

@@ -101,6 +101,7 @@
 #define cpu_has_avx512dq        boot_cpu_has(X86_FEATURE_AVX512DQ)
 #define cpu_has_rdseed          boot_cpu_has(X86_FEATURE_RDSEED)
 #define cpu_has_smap            boot_cpu_has(X86_FEATURE_SMAP)
+#define cpu_has_avx512_ifma     boot_cpu_has(X86_FEATURE_AVX512_IFMA)
 #define cpu_has_avx512er        boot_cpu_has(X86_FEATURE_AVX512ER)
 #define cpu_has_avx512cd        boot_cpu_has(X86_FEATURE_AVX512CD)
 #define cpu_has_sha             boot_cpu_has(X86_FEATURE_SHA)

xen/include/public/arch-x86/cpufeatureset.h

@@ -212,7 +212,7 @@ XEN_CPUFEATURE(AVX512DQ,      5*32+17) /*A  AVX-512 Doubleword & Quadword Instrs
 XEN_CPUFEATURE(RDSEED,        5*32+18) /*A  RDSEED instruction */
 XEN_CPUFEATURE(ADX,           5*32+19) /*A  ADCX, ADOX instructions */
 XEN_CPUFEATURE(SMAP,          5*32+20) /*S  Supervisor Mode Access Prevention */
-XEN_CPUFEATURE(AVX512IFMA,    5*32+21) /*A  AVX-512 Integer Fused Multiply Add */
+XEN_CPUFEATURE(AVX512_IFMA,   5*32+21) /*A  AVX-512 Integer Fused Multiply Add */
 XEN_CPUFEATURE(CLFLUSHOPT,    5*32+23) /*A  CLFLUSHOPT instruction */
 XEN_CPUFEATURE(CLWB,          5*32+24) /*A  CLWB instruction */
 XEN_CPUFEATURE(AVX512PF,      5*32+26) /*A  AVX-512 Prefetch Instructions */

xen/tools/gen-cpuid.py

@@ -261,7 +261,7 @@ def crunch_numbers(state):
         # (which in practice depends on the EVEX prefix to encode) as well
         # as mask registers, and the instructions themselves. All further
         # AVX512 features are built on top of AVX512F
-        AVX512F: [AVX512DQ, AVX512IFMA, AVX512PF, AVX512ER, AVX512CD,
+        AVX512F: [AVX512DQ, AVX512_IFMA, AVX512PF, AVX512ER, AVX512CD,
                   AVX512BW, AVX512VL, AVX512_4VNNIW, AVX512_4FMAPS,
                   AVX512_VPOPCNTDQ],