xen-project/xen
1
0 Fork 1
mirror of https://github.com/xen-project/xen.git synced 2026-10-29 18:50:05 +01:00
Code Issues Activity

x86: AVX instruction emulation fixes

Browse Source 
- 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@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
master commit: 062919448e
master date: 2013-08-28 17:03:50 +0200
This commit is contained in:
Jan Beulich committed 2013-09-12 11:26:40 +02:00
1 parent 3f8a4aa9c1
commit b8656cdad7
2 files changed
+145 -15
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

tools/tests/x86_emulator/test_x86_emulator.c
+138 -6
View File
@@ -94,13 +94,25 @@ static inline uint64_t xgetbv(uint32_t xcr)
}
#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__)
xen/arch/x86/x86_emulate/x86_emulate.c
+7 -9
View File
@@ -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);
@@ -3902,8 +3899,9 @@ 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;
@@ -4171,7 +4169,7 @@ 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);
Reference in new issue
xen-project/xen
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.

The note is not visible to the blocked user.