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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] x86: AVX instruction emulation fixes
- we used the C4/C5 (first prefix) byte instead of the apparent ModR/M
one as the second prefix byte
- early decoding normalized vex.reg, thus corrupting it for the main
consumer (copy_REX_VEX()), resulting in #UD on the two-operand
instructions we emulate
Also add respective test cases to the testing utility plus
- fix get_fpu() (the fall-through order was inverted)
- add cpu_has_avx2, even if it's currently unused (as in the new test
cases I decided to refrain from using AVX2 instructions in order to
be able to actually run all the tests on the hardware I have)
- slightly tweak cpu_has_avx to more consistently express the outputs
we don't care about (sinking them all into the same variable)
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -94,13 +94,25 @@ static inline uint64_t xgetbv(uint32_t x
}
#define cpu_has_avx ({ \
- unsigned int eax = 1, ecx = 0, edx; \
- cpuid(&eax, &edx, &ecx, &edx, NULL); \
+ unsigned int eax = 1, ecx = 0; \
+ cpuid(&eax, &eax, &ecx, &eax, NULL); \
if ( !(ecx & (1U << 27)) || ((xgetbv(0) & 6) != 6) ) \
ecx = 0; \
(ecx & (1U << 28)) != 0; \
})
+#define cpu_has_avx2 ({ \
+ unsigned int eax = 1, ebx, ecx = 0; \
+ cpuid(&eax, &ebx, &ecx, &eax, NULL); \
+ if ( !(ecx & (1U << 27)) || ((xgetbv(0) & 6) != 6) ) \
+ ebx = 0; \
+ else { \
+ eax = 7, ecx = 0; \
+ cpuid(&eax, &ebx, &ecx, &eax, NULL); \
+ } \
+ (ebx & (1U << 5)) != 0; \
+})
+
int get_fpu(
void (*exception_callback)(void *, struct cpu_user_regs *),
void *exception_callback_arg,
@@ -111,14 +123,14 @@ int get_fpu(
{
case X86EMUL_FPU_fpu:
break;
- case X86EMUL_FPU_ymm:
- if ( cpu_has_avx )
+ case X86EMUL_FPU_mmx:
+ if ( cpu_has_mmx )
break;
case X86EMUL_FPU_xmm:
if ( cpu_has_sse )
break;
- case X86EMUL_FPU_mmx:
- if ( cpu_has_mmx )
+ case X86EMUL_FPU_ymm:
+ if ( cpu_has_avx )
break;
default:
return X86EMUL_UNHANDLEABLE;
@@ -629,6 +641,73 @@ int main(int argc, char **argv)
else
printf("skipped\n");
+ printf("%-40s", "Testing vmovdqu %ymm2,(%ecx)...");
+ if ( stack_exec && cpu_has_avx )
+ {
+ extern const unsigned char vmovdqu_to_mem[];
+
+ asm volatile ( "vpcmpeqb %%xmm2, %%xmm2, %%xmm2\n"
+ ".pushsection .test, \"a\", @progbits\n"
+ "vmovdqu_to_mem: vmovdqu %%ymm2, (%0)\n"
+ ".popsection" :: "c" (NULL) );
+
+ memcpy(instr, vmovdqu_to_mem, 15);
+ memset(res, 0x55, 128);
+ memset(res + 16, 0xff, 16);
+ memset(res + 20, 0x00, 16);
+ regs.eip = (unsigned long)&instr[0];
+ regs.ecx = (unsigned long)res;
+ rc = x86_emulate(&ctxt, &emulops);
+ if ( (rc != X86EMUL_OKAY) || memcmp(res, res + 16, 64) )
+ goto fail;
+ printf("okay\n");
+ }
+ else
+ printf("skipped\n");
+
+ printf("%-40s", "Testing vmovdqu (%edx),%ymm4...");
+ if ( stack_exec && cpu_has_avx )
+ {
+ extern const unsigned char vmovdqu_from_mem[];
+
+#if 0 /* Don't use AVX2 instructions for now */
+ asm volatile ( "vpcmpgtb %%ymm4, %%ymm4, %%ymm4\n"
+#else
+ asm volatile ( "vpcmpgtb %%xmm4, %%xmm4, %%xmm4\n\t"
+ "vinsertf128 $1, %%xmm4, %%ymm4, %%ymm4\n"
+#endif
+ ".pushsection .test, \"a\", @progbits\n"
+ "vmovdqu_from_mem: vmovdqu (%0), %%ymm4\n"
+ ".popsection" :: "d" (NULL) );
+
+ memcpy(instr, vmovdqu_from_mem, 15);
+ memset(res + 4, 0xff, 16);
+ regs.eip = (unsigned long)&instr[0];
+ regs.ecx = 0;
+ regs.edx = (unsigned long)res;
+ rc = x86_emulate(&ctxt, &emulops);
+ if ( rc != X86EMUL_OKAY )
+ 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 %%ymm1, %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 != 0xffffffff )
+ goto fail;
+ printf("okay\n");
+ }
+ else
+ printf("skipped\n");
+
printf("%-40s", "Testing movsd %xmm5,(%ecx)...");
memset(res, 0x77, 64);
memset(res + 10, 0x66, 8);
@@ -683,6 +762,59 @@ int main(int argc, char **argv)
else
printf("skipped\n");
+ printf("%-40s", "Testing vmovsd %xmm5,(%ecx)...");
+ memset(res, 0x88, 64);
+ memset(res + 10, 0x77, 8);
+ if ( stack_exec && cpu_has_avx )
+ {
+ extern const unsigned char vmovsd_to_mem[];
+
+ asm volatile ( "vbroadcastsd %0, %%ymm5\n"
+ ".pushsection .test, \"a\", @progbits\n"
+ "vmovsd_to_mem: vmovsd %%xmm5, (%1)\n"
+ ".popsection" :: "m" (res[10]), "c" (NULL) );
+
+ memcpy(instr, vmovsd_to_mem, 15);
+ regs.eip = (unsigned long)&instr[0];
+ regs.ecx = (unsigned long)(res + 2);
+ regs.edx = 0;
+ rc = x86_emulate(&ctxt, &emulops);
+ if ( (rc != X86EMUL_OKAY) || memcmp(res, res + 8, 32) )
+ goto fail;
+ printf("okay\n");
+ }
+ else
+ {
+ printf("skipped\n");
+ memset(res + 2, 0x77, 8);
+ }
+
+ printf("%-40s", "Testing vmovaps (%edx),%ymm7...");
+ if ( stack_exec && cpu_has_avx )
+ {
+ extern const unsigned char vmovaps_from_mem[];
+
+ asm volatile ( "vxorps %%ymm7, %%ymm7, %%ymm7\n"
+ ".pushsection .test, \"a\", @progbits\n"
+ "vmovaps_from_mem: vmovaps (%0), %%ymm7\n"
+ ".popsection" :: "d" (NULL) );
+
+ memcpy(instr, vmovaps_from_mem, 15);
+ regs.eip = (unsigned long)&instr[0];
+ regs.ecx = 0;
+ regs.edx = (unsigned long)res;
+ rc = x86_emulate(&ctxt, &emulops);
+ if ( rc != X86EMUL_OKAY )
+ goto fail;
+ asm ( "vcmpeqps %1, %%ymm7, %%ymm0\n\t"
+ "vmovmskps %%ymm0, %0" : "=r" (rc) : "m" (res[8]) );
+ if ( rc != 0xff )
+ goto fail;
+ printf("okay\n");
+ }
+ else
+ printf("skipped\n");
+
for ( j = 1; j <= 2; j++ )
{
#if defined(__i386__)
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1454,10 +1454,10 @@ x86_emulate(
/* VEX */
generate_exception_if(rex_prefix || vex.pfx, EXC_UD, -1);
- vex.raw[0] = b;
+ vex.raw[0] = modrm;
if ( b & 1 )
{
- vex.raw[1] = b;
+ vex.raw[1] = modrm;
vex.opcx = vex_0f;
vex.x = 1;
vex.b = 1;
@@ -1479,10 +1479,7 @@ x86_emulate(
}
}
}
- vex.reg ^= 0xf;
- if ( !mode_64bit() )
- vex.reg &= 0x7;
- else if ( !vex.r )
+ if ( mode_64bit() && !vex.r )
rex_prefix |= REX_R;
fail_if(vex.opcx != vex_0f);
@@ -3899,8 +3896,9 @@ x86_emulate(
else
{
fail_if((vex.opcx != vex_0f) ||
- (vex.reg && ((ea.type == OP_MEM) ||
- !(vex.pfx & VEX_PREFIX_SCALAR_MASK))));
+ ((vex.reg != 0xf) &&
+ ((ea.type == OP_MEM) ||
+ !(vex.pfx & VEX_PREFIX_SCALAR_MASK))));
vcpu_must_have_avx();
get_fpu(X86EMUL_FPU_ymm, &fic);
ea.bytes = 16 << vex.l;
@@ -4168,7 +4166,7 @@ x86_emulate(
}
else
{
- fail_if((vex.opcx != vex_0f) || vex.reg ||
+ fail_if((vex.opcx != vex_0f) || (vex.reg != 0xf) ||
((vex.pfx != vex_66) && (vex.pfx != vex_f3)));
vcpu_must_have_avx();
get_fpu(X86EMUL_FPU_ymm, &fic);
Attachment:
x86-emul-test-AVX.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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