--- a/tools/tests/x86_emulator/evex-disp8.c
+++ b/tools/tests/x86_emulator/evex-disp8.c
@@ -1001,7 +1001,11 @@ static void test_group(const struct test
         for ( j = 0; j < nr_vl; ++j )
         {
             if ( vl[0] == VL_512 && vl[j] != VL_512 &&
-                 !cpu_policy.feat.avx512vl )
+                 !cpu_policy.feat.avx512vl && !cpu_policy.feat.avx10 )
+                continue;
+
+            if ( vl[j] == VL_512 && !cpu_policy.feat.avx512f &&
+                 !cpu_policy.avx10.vsz512 )
                 continue;
 
             switch ( tests[i].esz )
@@ -1052,6 +1056,27 @@ static void test_group(const struct test
     }
 }
 
+/* AVX512 (sub)features implied by AVX10. */
+#define avx10_has_avx512f             true
+#define avx10_has_avx512bw            true
+#define avx10_has_avx512cd            true
+#define avx10_has_avx512dq            true
+#define avx10_has_avx512_bf16         true
+#define avx10_has_avx512_bitalg       true
+#define avx10_has_avx512_fp16         true
+#define avx10_has_avx512_ifma         true
+#define avx10_has_avx512_vbmi         true
+#define avx10_has_avx512_vbmi2        true
+#define avx10_has_avx512_vnni         true
+#define avx10_has_avx512_vpopcntdq    true
+
+/* AVX512 sub-features /not/ implied by AVX10. */
+#define avx10_has_avx512er            false
+#define avx10_has_avx512pf            false
+#define avx10_has_avx512_4fmaps       false
+#define avx10_has_avx512_4vnniw       false
+#define avx10_has_avx512_vp2intersect false
+
 void evex_disp8_test(void *instr, struct x86_emulate_ctxt *ctxt,
                      const struct x86_emulate_ops *ops)
 {
@@ -1059,8 +1084,8 @@ void evex_disp8_test(void *instr, struct
     emulops.read = read;
     emulops.write = write;
 
-#define RUN(feat, vl) do { \
-    if ( cpu_has_##feat ) \
+#define run(cond, feat, vl) do { \
+    if ( cond ) \
     { \
         printf("%-40s", "Testing " #feat "/" #vl " disp8 handling..."); \
         test_group(feat ## _ ## vl, ARRAY_SIZE(feat ## _ ## vl), \
@@ -1069,6 +1094,12 @@ void evex_disp8_test(void *instr, struct
     } \
 } while ( false )
 
+#define RUN(feat, vl) \
+    run(cpu_has_ ## feat || \
+        (cpu_has_avx10_1 && cpu_policy.avx10.vsz256 && avx10_has_ ## feat && \
+         (ARRAY_SIZE(vl_ ## vl) > 1 || &vl_ ## vl[0] != &vl_512[0])), \
+       feat, vl)
+
     RUN(avx512f, all);
     RUN(avx512f, 128);
     RUN(avx512f, no128);
@@ -1091,10 +1122,15 @@ void evex_disp8_test(void *instr, struct
     RUN(avx512_fp16, all);
     RUN(avx512_fp16, 128);
 
-    if ( cpu_has_avx512f )
+#undef RUN
+
+    if ( cpu_has_avx512f || cpu_has_avx10_1 )
     {
+#define RUN(feat, vl) run(cpu_has_ ## feat, feat, vl)
         RUN(gfni, all);
         RUN(vaes, all);
         RUN(vpclmulqdq, all);
+#undef RUN
     }
+#undef run
 }
--- a/tools/tests/x86_emulator/testcase.mk
+++ b/tools/tests/x86_emulator/testcase.mk
@@ -4,7 +4,27 @@ include $(XEN_ROOT)/tools/Rules.mk
 
 $(call cc-options-add,CFLAGS,CC,$(EMBEDDED_EXTRA_CFLAGS))
 
-CFLAGS += -fno-builtin -g0 $($(TESTCASE)-cflags)
+ifneq ($(filter -mavx512%,$($(TESTCASE)-cflags)),)
+
+cflags-vsz64 :=
+cflags-vsz32 := -mprefer-vector-width=256
+cflags-vsz16 := -mprefer-vector-width=128
+# Scalar tests don't set VEC_SIZE (and VEC_MAX is used by S/G ones only)
+cflags-vsz   := -mprefer-vector-width=128
+
+ifneq ($(filter -DVEC_SIZE=%,$($(TESTCASE)-cflags)),)
+CFLAGS-VSZ := $(cflags-vsz$(patsubst -DVEC_SIZE=%,%,$(filter -DVEC_SIZE=%,$($(TESTCASE)-cflags))))
+else
+CFLAGS-VSZ := $(cflags-vsz$(patsubst -DVEC_MAX=%,%,$(filter -DVEC_MAX=%,$($(TESTCASE)-cflags))))
+endif
+
+else
+
+CFLAGS-VSZ :=
+
+endif
+
+CFLAGS += -fno-builtin -g0 $($(TESTCASE)-cflags) $(CFLAGS-VSZ)
 
 LDFLAGS_DIRECT += $(shell { $(LD) -v --warn-rwx-segments; } >/dev/null 2>&1 && echo --no-warn-rwx-segments)
 
--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -124,52 +124,61 @@ static bool simd_check_avx_pclmul(void)
 
 static bool simd_check_avx512f(void)
 {
-    return cpu_has_avx512f;
+    return cpu_has_avx512f || cpu_has_avx10_1_512;
 }
-#define simd_check_avx512f_opmask simd_check_avx512f
 #define simd_check_avx512f_sg simd_check_avx512f
 
+static bool simd_check_avx512f_sc(void)
+{
+    return cpu_has_avx512f || cpu_has_avx10_1;
+}
+#define simd_check_avx512f_opmask simd_check_avx512f_sc
+
 static bool simd_check_avx512f_vl(void)
 {
-    return cpu_has_avx512f && cpu_policy.feat.avx512vl;
+    return (cpu_has_avx512f && cpu_policy.feat.avx512vl) ||
+           cpu_has_avx10_1_256;
 }
 #define simd_check_avx512vl_sg simd_check_avx512f_vl
 
 static bool simd_check_avx512dq(void)
 {
-    return cpu_has_avx512dq;
+    return cpu_has_avx512dq || cpu_has_avx10_1_512;
 }
 #define simd_check_avx512dq_opmask simd_check_avx512dq
 
 static bool simd_check_avx512dq_vl(void)
 {
-    return cpu_has_avx512dq && cpu_policy.feat.avx512vl;
+    return (cpu_has_avx512dq && cpu_policy.feat.avx512vl) ||
+           cpu_has_avx10_1_256;
 }
 
 static bool simd_check_avx512bw(void)
 {
-    return cpu_has_avx512bw;
+    return cpu_has_avx512bw || cpu_has_avx10_1_512;
 }
 #define simd_check_avx512bw_opmask simd_check_avx512bw
 
 static bool simd_check_avx512bw_vl(void)
 {
-    return cpu_has_avx512bw && cpu_policy.feat.avx512vl;
+    return (cpu_has_avx512bw && cpu_policy.feat.avx512vl) ||
+           cpu_has_avx10_1_256;
 }
 
 static bool simd_check_avx512vbmi(void)
 {
-    return cpu_has_avx512_vbmi;
+    return cpu_has_avx512_vbmi || cpu_has_avx10_1_512;
 }
 
 static bool simd_check_avx512vbmi_vl(void)
 {
-    return cpu_has_avx512_vbmi && cpu_policy.feat.avx512vl;
+    return (cpu_has_avx512_vbmi && cpu_policy.feat.avx512vl) ||
+           cpu_has_avx10_1_256;
 }
 
 static bool simd_check_avx512vbmi2(void)
 {
-    return cpu_has_avx512_vbmi2;
+    return cpu_has_avx512_vbmi2 || cpu_has_avx10_1_512;
 }
 
 static bool simd_check_sse4_sha(void)
@@ -250,17 +259,23 @@ static bool simd_check_avx512bw_gf_vl(vo
 
 static bool simd_check_avx512vnni(void)
 {
-    return cpu_has_avx512_vnni;
+    return cpu_has_avx512_vnni || cpu_has_avx10_1_512;
 }
 
 static bool simd_check_avx512fp16(void)
 {
-    return cpu_has_avx512_fp16;
+    return cpu_has_avx512_fp16 || cpu_has_avx10_1_512;
+}
+
+static bool simd_check_avx512fp16_sc(void)
+{
+    return cpu_has_avx512_fp16 || cpu_has_avx10_1;
 }
 
 static bool simd_check_avx512fp16_vl(void)
 {
-    return cpu_has_avx512_fp16 && cpu_policy.feat.avx512vl;
+    return (cpu_has_avx512_fp16 && cpu_policy.feat.avx512vl) ||
+           cpu_has_avx10_1_256;
 }
 
 static void simd_set_regs(struct cpu_user_regs *regs)
@@ -433,9 +448,13 @@ static const struct {
     SIMD(OPMASK+DQ/w, avx512dq_opmask,         2),
     SIMD(OPMASK+BW/d, avx512bw_opmask,         4),
     SIMD(OPMASK+BW/q, avx512bw_opmask,         8),
-    SIMD(AVX512F f32 scalar,  avx512f,        f4),
+#define avx512f_sc_x86_32_D_f4 avx512f_x86_32_D_f4
+#define avx512f_sc_x86_64_D_f4 avx512f_x86_64_D_f4
+    SIMD(AVX512F f32 scalar,  avx512f_sc,     f4),
     SIMD(AVX512F f32x16,      avx512f,      64f4),
-    SIMD(AVX512F f64 scalar,  avx512f,        f8),
+#define avx512f_sc_x86_32_D_f8 avx512f_x86_32_D_f8
+#define avx512f_sc_x86_64_D_f8 avx512f_x86_64_D_f8
+    SIMD(AVX512F f64 scalar,  avx512f_sc,     f8),
     SIMD(AVX512F f64x8,       avx512f,      64f8),
     SIMD(AVX512F s32x16,      avx512f,      64i4),
     SIMD(AVX512F u32x16,      avx512f,      64u4),
@@ -523,7 +542,9 @@ static const struct {
     AVX512VL(_VBMI+VL u16x8, avx512vbmi,    16u2),
     AVX512VL(_VBMI+VL s16x16, avx512vbmi,   32i2),
     AVX512VL(_VBMI+VL u16x16, avx512vbmi,   32u2),
-    SIMD(AVX512_FP16 f16 scal,avx512fp16,     f2),
+#define avx512fp16_sc_x86_32_D_f2 avx512fp16_x86_32_D_f2
+#define avx512fp16_sc_x86_64_D_f2 avx512fp16_x86_64_D_f2
+    SIMD(AVX512_FP16 f16 scal,avx512fp16_sc,  f2),
     SIMD(AVX512_FP16 f16x32, avx512fp16,    64f2),
     AVX512VL(_FP16+VL f16x8, avx512fp16,    16f2),
     AVX512VL(_FP16+VL f16x16,avx512fp16,    32f2),
@@ -2810,7 +2831,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovq %xmm1,32(%edx)...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovq_to_mem);
 
@@ -2834,7 +2855,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovq 32(%edx),%xmm0...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovq_from_mem);
 
@@ -2846,11 +2867,22 @@ int main(int argc, char **argv)
         rc = x86_emulate(&ctxt, &emulops);
         if ( rc != X86EMUL_OKAY || !check_eip(evex_vmovq_from_mem) )
             goto fail;
-        asm ( "vmovq %1, %%xmm1\n\t"
-              "vpcmpeqq %%zmm0, %%zmm1, %%k0\n"
-              "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
-        if ( rc != 0xff )
-            goto fail;
+        if ( simd_check_avx512f() )
+        {
+            asm ( "vmovq %1, %%xmm1\n\t"
+                  "vpcmpeqq %%zmm0, %%zmm1, %%k0\n"
+                  "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0x00ff )
+                goto fail;
+        }
+        else
+        {
+            asm ( "vmovq %1, %%xmm1\n\t"
+                  "vpcmpeqq %%xmm0, %%xmm1, %%k0\n"
+                  "kmovb %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0x03 )
+                goto fail;
+        }
         printf("okay\n");
     }
     else
@@ -3172,7 +3204,7 @@ int main(int argc, char **argv)
     printf("%-40s", "Testing vmovsd %xmm5,16(%ecx){%k3}...");
     memset(res, 0x88, 128);
     memset(res + 20, 0x77, 8);
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(vmovsd_masked_to_mem);
 
@@ -3390,7 +3422,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovd %xmm3,32(%ecx)...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovd_to_mem);
 
@@ -3415,7 +3447,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovd 32(%ecx),%xmm4...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovd_from_mem);
 
@@ -3428,11 +3460,22 @@ int main(int argc, char **argv)
         rc = x86_emulate(&ctxt, &emulops);
         if ( rc != X86EMUL_OKAY || !check_eip(evex_vmovd_from_mem) )
             goto fail;
-        asm ( "vmovd %1, %%xmm0\n\t"
-              "vpcmpeqd %%zmm4, %%zmm0, %%k0\n\t"
-              "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
-        if ( rc != 0xffff )
-            goto fail;
+        if ( simd_check_avx512f() )
+        {
+            asm ( "vmovd %1, %%xmm0\n\t"
+                  "vpcmpeqd %%zmm4, %%zmm0, %%k0\n\t"
+                  "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0xffff )
+                goto fail;
+        }
+        else
+        {
+            asm ( "vmovd %1, %%xmm0\n\t"
+                  "vpcmpeqd %%xmm4, %%xmm0, %%k0\n\t"
+                  "kmovb %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0x0f )
+                goto fail;
+        }
         printf("okay\n");
     }
     else
@@ -3605,7 +3648,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovd %xmm2,%ebx...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovd_to_reg);
 
@@ -3631,7 +3674,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovd %ebx,%xmm1...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovd_from_reg);
 
@@ -3645,11 +3688,22 @@ int main(int argc, char **argv)
         rc = x86_emulate(&ctxt, &emulops);
         if ( (rc != X86EMUL_OKAY) || !check_eip(evex_vmovd_from_reg) )
             goto fail;
-        asm ( "vmovd %1, %%xmm0\n\t"
-              "vpcmpeqd %%zmm1, %%zmm0, %%k0\n\t"
-              "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
-        if ( rc != 0xffff )
-            goto fail;
+        if ( simd_check_avx512f() )
+        {
+            asm ( "vmovd %1, %%xmm0\n\t"
+                  "vpcmpeqd %%zmm1, %%zmm0, %%k0\n\t"
+                  "kmovw %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0xffff )
+                goto fail;
+        }
+        else
+        {
+            asm ( "vmovd %1, %%xmm0\n\t"
+                  "vpcmpeqd %%xmm1, %%xmm0, %%k0\n\t"
+                  "kmovb %%k0, %0" : "=r" (rc) : "m" (res[8]) );
+            if ( rc != 0x0f )
+                goto fail;
+        }
         printf("okay\n");
     }
     else
@@ -3733,7 +3787,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing {evex} vmovq %xmm11,32(%ecx)...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovq_to_mem2);
 
@@ -3823,7 +3877,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing vmovq %xmm22,%rbx...");
-    if ( stack_exec && simd_check_avx512f() )
+    if ( stack_exec && simd_check_avx512f_sc() )
     {
         decl_insn(evex_vmovq_to_reg);
 
@@ -5114,7 +5168,7 @@ int main(int argc, char **argv)
         printf("skipped\n");
 
     printf("%-40s", "Testing vmovsh 8(%ecx),%xmm5...");
-    if ( stack_exec && simd_check_avx512fp16() )
+    if ( stack_exec && simd_check_avx512fp16_sc() )
     {
         decl_insn(vmovsh_from_mem);
         decl_insn(vmovw_to_gpr);
@@ -5132,14 +5186,28 @@ int main(int argc, char **argv)
         rc = x86_emulate(&ctxt, &emulops);
         if ( (rc != X86EMUL_OKAY) || !check_eip(vmovsh_from_mem) )
             goto fail;
-        asm volatile ( "kmovw     %2, %%k1\n\t"
-                       "vmovdqu16 %1, %%zmm4%{%%k1%}%{z%}\n\t"
-                       "vpcmpeqw  %%zmm4, %%zmm5, %%k0\n\t"
-                       "kmovw     %%k0, %0"
-                       : "=g" (rc)
-                       : "m" (res[2]), "r" (1) );
-        if ( rc != 0xffff )
-            goto fail;
+        if ( simd_check_avx512fp16() )
+        {
+            asm volatile ( "kmovw     %2, %%k1\n\t"
+                           "vmovdqu16 %1, %%zmm4%{%%k1%}%{z%}\n\t"
+                           "vpcmpeqw  %%zmm4, %%zmm5, %%k0\n\t"
+                           "kmovw     %%k0, %0"
+                           : "=g" (rc)
+                           : "m" (res[2]), "r" (1) );
+            if ( rc != 0xffff )
+                goto fail;
+        }
+        else
+        {
+            asm volatile ( "kmovb     %2, %%k1\n\t"
+                           "vmovdqu16 %1, %%xmm4%{%%k1%}%{z%}\n\t"
+                           "vpcmpeqw  %%xmm4, %%xmm5, %%k0\n\t"
+                           "kmovb     %%k0, %0"
+                           : "=g" (rc)
+                           : "m" (res[2]), "r" (1) );
+            if ( rc != 0xff )
+                goto fail;
+        }
         printf("okay\n");
 
         printf("%-40s", "Testing vmovsh %xmm4,2(%eax){%k3}...");
--- a/tools/tests/x86_emulator/x86-emulate.c
+++ b/tools/tests/x86_emulator/x86-emulate.c
@@ -240,7 +240,7 @@ int emul_test_get_fpu(
             break;
     case X86EMUL_FPU_opmask:
     case X86EMUL_FPU_zmm:
-        if ( cpu_has_avx512f )
+        if ( cpu_has_avx512f || cpu_has_avx10_1 )
             break;
     default:
         return X86EMUL_UNHANDLEABLE;
--- a/tools/tests/x86_emulator/x86-emulate.h
+++ b/tools/tests/x86_emulator/x86-emulate.h
@@ -181,6 +181,12 @@ void wrpkru(unsigned int val);
 #define cpu_has_avx_vnni_int8 (cpu_policy.feat.avx_vnni_int8 && xcr0_mask(6))
 #define cpu_has_avx_ne_convert (cpu_policy.feat.avx_ne_convert && xcr0_mask(6))
 #define cpu_has_avx_vnni_int16 (cpu_policy.feat.avx_vnni_int16 && xcr0_mask(6))
+                           /* TBD: Is bit 6 (ZMM_Hi256) really needed here? */
+#define cpu_has_avx10_1    (cpu_policy.feat.avx10 && xcr0_mask(0xe6))
+#define cpu_has_avx10_1_256 (cpu_has_avx10_1 && \
+                             (cpu_policy.avx10.vsz256 || \
+                              cpu_policy.avx10.vsz512))
+#define cpu_has_avx10_1_512 (cpu_has_avx10_1 && cpu_policy.avx10.vsz512)
 
 #define cpu_has_xgetbv1   (cpu_has_xsave && cpu_policy.xstate.xgetbv1)
 
