[Xen-devel] [PATCH 8/8] x86emul: support {,V}MOVNTDQA

["Jan Beulich" <JBeulich@xxxxxxxx>]

... as the only post-SSE2 move insn.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
v2: Re-base.

--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -2354,6 +2354,74 @@ int main(int argc, char **argv)
     else
         printf("skipped\n");
 
+    printf("%-40s", "Testing movntdqa 16(%edx),%xmm4...");
+    if ( stack_exec && cpu_has_sse4_1 )
+    {
+        decl_insn(movntdqa);
+
+        asm volatile ( "pcmpgtb %%xmm4, %%xmm4\n"
+                       put_insn(movntdqa, "movntdqa 16(%0), %%xmm4")
+                       :: "d" (NULL) );
+
+        set_insn(movntdqa);
+        memset(res, 0x55, 64);
+        memset(res + 4, 0xff, 16);
+        regs.edx = (unsigned long)res;
+        rc = x86_emulate(&ctxt, &emulops);
+        if ( rc != X86EMUL_OKAY || !check_eip(movntdqa) )
+            goto fail;
+        asm ( "pcmpeqb %%xmm2, %%xmm2\n\t"
+              "pcmpeqb %%xmm4, %%xmm2\n\t"
+              "pmovmskb %%xmm2, %0" : "=r" (rc) );
+        if ( rc != 0xffff )
+            goto fail;
+        printf("okay\n");
+    }
+    else
+        printf("skipped\n");
+
+    printf("%-40s", "Testing vmovntdqa (%ecx),%ymm4...");
+    if ( stack_exec && cpu_has_avx2 )
+    {
+        decl_insn(vmovntdqa);
+
+#if 0 /* Don't use AVX2 instructions for now */
+        asm volatile ( "vpxor %%ymm4, %%ymm4, %%ymm4\n"
+                       put_insn(vmovntdqa, "vmovntdqa (%0), %%ymm4")
+                       :: "c" (NULL) );
+#else
+        asm volatile ( "vpxor %xmm4, %xmm4, %xmm4\n"
+                       put_insn(vmovntdqa,
+                                ".byte 0xc4, 0xe2, 0x7d, 0x2a, 0x21") );
+#endif
+
+        set_insn(vmovntdqa);
+        memset(res, 0x55, 96);
+        memset(res + 8, 0xff, 32);
+        regs.ecx = (unsigned long)(res + 8);
+        rc = x86_emulate(&ctxt, &emulops);
+        if ( rc != X86EMUL_OKAY || !check_eip(vmovntdqa) )
+            goto fail;
+#if 0 /* Don't use AVX2 instructions for now */
+        asm ( "vpcmpeqb %%ymm2, %%ymm2, %%ymm2\n\t"
+              "vpcmpeqb %%ymm4, %%ymm2, %%ymm0\n\t"
+              "vpmovmskb %%ymm0, %0" : "=r" (rc) );
+#else
+        asm ( "vextractf128 $1, %%ymm4, %%xmm3\n\t"
+              "vpcmpeqb %%xmm2, %%xmm2, %%xmm2\n\t"
+              "vpcmpeqb %%xmm4, %%xmm2, %%xmm0\n\t"
+              "vpcmpeqb %%xmm3, %%xmm2, %%xmm1\n\t"
+              "vpmovmskb %%xmm0, %0\n\t"
+              "vpmovmskb %%xmm1, %1" : "=r" (rc), "=r" (i) );
+        rc |= i << 16;
+#endif
+        if ( ~rc )
+            goto fail;
+        printf("okay\n");
+    }
+    else
+        printf("skipped\n");
+
     printf("%-40s", "Testing stmxcsr (%edx)...");
     if ( cpu_has_sse )
     {
--- a/tools/tests/x86_emulator/x86_emulate.h
+++ b/tools/tests/x86_emulator/x86_emulate.h
@@ -95,6 +95,12 @@ static inline uint64_t xgetbv(uint32_t x
     (res.c & (1U << 0)) != 0; \
 })
 
+#define cpu_has_sse4_1 ({ \
+    struct cpuid_leaf res; \
+    emul_test_cpuid(1, 0, &res, NULL); \
+    (res.c & (1U << 19)) != 0; \
+})
+
 #define cpu_has_popcnt ({ \
     struct cpuid_leaf res; \
     emul_test_cpuid(1, 0, &res, NULL); \
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1449,6 +1449,7 @@ static bool vcpu_has(
 #define vcpu_has_sse2()        vcpu_has(         1, EDX, 26, ctxt, ops)
 #define vcpu_has_sse3()        vcpu_has(         1, ECX,  0, ctxt, ops)
 #define vcpu_has_cx16()        vcpu_has(         1, ECX, 13, ctxt, ops)
+#define vcpu_has_sse4_1()      vcpu_has(         1, ECX, 19, ctxt, ops)
 #define vcpu_has_sse4_2()      vcpu_has(         1, ECX, 20, ctxt, ops)
 #define vcpu_has_movbe()       vcpu_has(         1, ECX, 22, ctxt, ops)
 #define vcpu_has_popcnt()      vcpu_has(         1, ECX, 23, ctxt, ops)
@@ -5963,6 +5964,7 @@ x86_emulate(
     case X86EMUL_OPC_VEX_66(0x0f, 0x7f): /* vmovdqa {x,y}mm,{x,y}mm/m128 */
     case X86EMUL_OPC_F3(0x0f, 0x7f):     /* movdqu xmm,xmm/m128 */
     case X86EMUL_OPC_VEX_F3(0x0f, 0x7f): /* vmovdqu {x,y}mm,{x,y}mm/mem */
+    movdqa:
         if ( vex.opcx != vex_none )
         {
             host_and_vcpu_must_have(avx);
@@ -6886,6 +6888,23 @@ x86_emulate(
         sfence = true;
         break;
 
+    case X86EMUL_OPC_66(0x0f38, 0x2a): /* movntdqa m128,xmm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0x2a): /* vmovntdqa mem,{x,y}mm */
+        generate_exception_if(ea.type != OP_MEM, EXC_UD);
+        /* Ignore the non-temporal hint for now, using movdqa instead. */
+        asm volatile ( "mfence" ::: "memory" );
+        b = 0x6f;
+        if ( vex.opcx == vex_none )
+            vcpu_must_have(sse4_1);
+        else
+        {
+            vex.opcx = vex_0f;
+            if ( vex.l )
+                vcpu_must_have(avx2);
+        }
+        state->simd_size = simd_packed_int;
+        goto movdqa;
+
     case X86EMUL_OPC(0x0f38, 0xf0): /* movbe m,r */
     case X86EMUL_OPC(0x0f38, 0xf1): /* movbe r,m */
         vcpu_must_have(movbe);

Attachment: x86emul-MOVNTDQA.patch
Description: Text document

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