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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 04/17] x86emul: support F16C insns
Note that this avoids emulating the behavior of VCVTPS2PH found on at
least some Intel CPUs, which update MXCSR even when the memory write
faults.
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
@@ -3053,6 +3053,47 @@ int main(int argc, char **argv)
printf("skipped\n");
#endif
+ printf("%-40s", "Testing vcvtph2ps (%ecx),%ymm1...");
+ if ( stack_exec && cpu_has_f16c )
+ {
+ decl_insn(vcvtph2ps);
+ decl_insn(vcvtps2ph);
+
+ asm volatile ( "vxorps %%xmm1, %%xmm1, %%xmm1\n"
+ put_insn(vcvtph2ps, "vcvtph2ps (%0), %%ymm1")
+ :: "c" (NULL) );
+
+ set_insn(vcvtph2ps);
+ res[1] = 0x40003c00; /* (1.0, 2.0) */
+ res[2] = 0x44004200; /* (3.0, 4.0) */
+ res[3] = 0x3400b800; /* (-.5, .25) */
+ res[4] = 0xbc000000; /* (0.0, -1.) */
+ memset(res + 5, 0xff, 16);
+ regs.ecx = (unsigned long)(res + 1);
+ rc = x86_emulate(&ctxt, &emulops);
+ asm volatile ( "vmovups %%ymm1, %0" : "=m" (res[16]) );
+ if ( rc != X86EMUL_OKAY || !check_eip(vcvtph2ps) )
+ goto fail;
+ printf("okay\n");
+
+ printf("%-40s", "Testing vcvtps2ph $0,%ymm1,(%edx)...");
+ asm volatile ( "vmovups %0, %%ymm1\n"
+ put_insn(vcvtps2ph, "vcvtps2ph $0, %%ymm1, (%1)")
+ :: "m" (res[16]), "d" (NULL) );
+
+ set_insn(vcvtps2ph);
+ memset(res + 7, 0, 32);
+ regs.edx = (unsigned long)(res + 7);
+ rc = x86_emulate(&ctxt, &emulops);
+ if ( rc != X86EMUL_OKAY || !check_eip(vcvtps2ph) ||
+ memcmp(res + 1, res + 7, 16) ||
+ res[11] || res[12] || res[13] || res[14] )
+ goto fail;
+ printf("okay\n");
+ }
+ else
+ printf("skipped\n");
+
#undef decl_insn
#undef put_insn
#undef set_insn
--- a/tools/tests/x86_emulator/x86_emulate.h
+++ b/tools/tests/x86_emulator/x86_emulate.h
@@ -127,6 +127,14 @@ static inline uint64_t xgetbv(uint32_t x
(res.c & (1U << 28)) != 0; \
})
+#define cpu_has_f16c ({ \
+ struct cpuid_leaf res; \
+ emul_test_cpuid(1, 0, &res, NULL); \
+ if ( !(res.c & (1U << 27)) || ((xgetbv(0) & 6) != 6) ) \
+ res.c = 0; \
+ (res.c & (1U << 29)) != 0; \
+})
+
#define cpu_has_avx2 ({ \
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
@@ -369,6 +369,7 @@ static const struct {
[0x00 ... 0x0b] = { .simd_size = simd_packed_int },
[0x0c ... 0x0f] = { .simd_size = simd_packed_fp },
[0x10] = { .simd_size = simd_packed_int },
+ [0x13] = { .simd_size = simd_other, .two_op = 1 },
[0x14 ... 0x15] = { .simd_size = simd_packed_fp },
[0x17] = { .simd_size = simd_packed_int, .two_op = 1 },
[0x18 ... 0x19] = { .simd_size = simd_scalar_fp, .two_op = 1 },
@@ -411,6 +412,7 @@ static const struct {
[0x14 ... 0x17] = { .simd_size = simd_none, .to_mem = 1, .two_op = 1 },
[0x18] = { .simd_size = simd_128 },
[0x19] = { .simd_size = simd_128, .to_mem = 1, .two_op = 1 },
+ [0x1d] = { .simd_size = simd_other, .to_mem = 1, .two_op = 1 },
[0x20] = { .simd_size = simd_none },
[0x21] = { .simd_size = simd_other },
[0x22] = { .simd_size = simd_none },
@@ -1601,6 +1603,7 @@ static bool vcpu_has(
#define vcpu_has_popcnt() vcpu_has( 1, ECX, 23, ctxt, ops)
#define vcpu_has_aesni() vcpu_has( 1, ECX, 25, ctxt, ops)
#define vcpu_has_avx() vcpu_has( 1, ECX, 28, ctxt, ops)
+#define vcpu_has_f16c() vcpu_has( 1, ECX, 29, ctxt, ops)
#define vcpu_has_rdrand() vcpu_has( 1, ECX, 30, ctxt, ops)
#define vcpu_has_mmxext() (vcpu_has(0x80000001, EDX, 22, ctxt, ops) || \
vcpu_has_sse())
@@ -7236,6 +7239,12 @@ x86_emulate(
host_and_vcpu_must_have(sse4_1);
goto simd_0f38_common;
+ case X86EMUL_OPC_VEX_66(0x0f38, 0x13): /* vcvtph2ps xmm/mem,{x,y}mm */
+ generate_exception_if(vex.w, EXC_UD);
+ host_and_vcpu_must_have(f16c);
+ op_bytes = 8 << vex.l;
+ goto simd_0f_ymm;
+
case X86EMUL_OPC_VEX_66(0x0f38, 0x20): /* vpmovsxbw xmm/mem,{x,y}mm */
case X86EMUL_OPC_VEX_66(0x0f38, 0x21): /* vpmovsxbd xmm/mem,{x,y}mm */
case X86EMUL_OPC_VEX_66(0x0f38, 0x22): /* vpmovsxbq xmm/mem,{x,y}mm */
@@ -7627,6 +7636,50 @@ x86_emulate(
opc = init_prefixes(stub);
goto pextr;
+ case X86EMUL_OPC_VEX_66(0x0f3a, 0x1d): /* vcvtps2ph $imm8,{x,y}mm,xmm/mem
*/
+ {
+ uint32_t mxcsr;
+
+ generate_exception_if(vex.w || vex.reg != 0xf, EXC_UD);
+ host_and_vcpu_must_have(f16c);
+ fail_if(!ops->write);
+
+ opc = init_prefixes(stub);
+ opc[0] = b;
+ opc[1] = modrm;
+ if ( ea.type == OP_MEM )
+ {
+ /* Convert memory operand to (%rAX). */
+ vex.b = 1;
+ opc[1] &= 0x38;
+ }
+ opc[2] = imm1;
+ fic.insn_bytes = PFX_BYTES + 3;
+ opc[3] = 0xc3;
+
+ copy_VEX(opc, vex);
+ /* Latch MXCSR - we may need to restore it below. */
+ invoke_stub("stmxcsr %[mxcsr]", "",
+ "=m" (*mmvalp), "+m" (fic.exn_raised), [mxcsr] "=m" (mxcsr)
+ : "a" (mmvalp));
+
+ put_stub(stub);
+ check_xmm_exn(&fic);
+
+ if ( ea.type == OP_MEM )
+ {
+ rc = ops->write(ea.mem.seg, ea.mem.off, mmvalp, 8 << vex.l, ctxt);
+ if ( rc != X86EMUL_OKAY )
+ {
+ asm volatile ( "ldmxcsr %0" :: "m" (mxcsr) );
+ goto done;
+ }
+ }
+
+ state->simd_size = simd_none;
+ break;
+ }
+
case X86EMUL_OPC_66(0x0f3a, 0x20): /* pinsrb $imm8,r32/m8,xmm */
case X86EMUL_OPC_66(0x0f3a, 0x22): /* pinsr{d,q} $imm8,r/m,xmm */
host_and_vcpu_must_have(sse4_1);
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -60,6 +60,7 @@
#define cpu_has_aesni boot_cpu_has(X86_FEATURE_AESNI)
#define cpu_has_xsave boot_cpu_has(X86_FEATURE_XSAVE)
#define cpu_has_avx boot_cpu_has(X86_FEATURE_AVX)
+#define cpu_has_f16c boot_cpu_has(X86_FEATURE_F16C)
#define cpu_has_rdrand boot_cpu_has(X86_FEATURE_RDRAND)
#define cpu_has_hypervisor boot_cpu_has(X86_FEATURE_HYPERVISOR)
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