From: "Jan Beulich" <JBeulich@suse.com>
To: xen-devel <xen-devel@lists.xenproject.org>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [PATCH v2 16/17] x86emul: make all FPU emulation use the stub
Date: Thu, 14 Sep 2017 09:21:17 -0600 [thread overview]
Message-ID: <59BABA8D020000780017B3FC@prv-mh.provo.novell.com> (raw)
In-Reply-To: <59BAB38A020000780017B34E@prv-mh.provo.novell.com>
While this means quite some reduction of (source) code, the main
purpose is to no longer have exceptions raised from other than stubs.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1261,28 +1261,25 @@ static inline bool fpu_check_write(void)
return !(fsw & FSW_ES);
}
-#define emulate_fpu_insn(_op) \
- asm volatile ( \
- "movb $2f-1f,%0 \n" \
- "1: " _op " \n" \
- "2: \n" \
- : "=m" (fic.insn_bytes) : : "memory" )
-
-#define emulate_fpu_insn_memdst(_op, _arg) \
- asm volatile ( \
- "movb $2f-1f,%0 \n" \
- "1: " _op " %1 \n" \
- "2: \n" \
- : "=m" (fic.insn_bytes), "=m" (_arg) \
- : : "memory" )
-
-#define emulate_fpu_insn_memsrc(_op, _arg) \
- asm volatile ( \
- "movb $2f-1f,%0 \n" \
- "1: " _op " %1 \n" \
- "2: \n" \
- : "=m" (fic.insn_bytes) \
- : "m" (_arg) : "memory" )
+#define emulate_fpu_insn_memdst(opc, ext, arg) \
+do { \
+ /* ModRM: mod=0, reg=ext, rm=0, i.e. a (%rax) operand */ \
+ fic.insn_bytes = 2; \
+ memcpy(get_stub(stub), \
+ ((uint8_t[]){ opc, ((ext) & 7) << 3, 0xc3 }), 3); \
+ invoke_stub("", "", "+m" (fic), "+m" (arg) : "a" (&(arg))); \
+ put_stub(stub); \
+} while (0)
+
+#define emulate_fpu_insn_memsrc(opc, ext, arg) \
+do { \
+ /* ModRM: mod=0, reg=ext, rm=0, i.e. a (%rax) operand */ \
+ fic.insn_bytes = 2; \
+ memcpy(get_stub(stub), \
+ ((uint8_t[]){ opc, ((ext) & 7) << 3, 0xc3 }), 3); \
+ invoke_stub("", "", "+m" (fic) : "m" (arg), "a" (&(arg))); \
+ put_stub(stub); \
+} while (0)
#define emulate_fpu_insn_stub(bytes...) \
do { \
@@ -3843,8 +3840,7 @@ x86_emulate(
case 0x9b: /* wait/fwait */
host_and_vcpu_must_have(fpu);
get_fpu(X86EMUL_FPU_wait, &fic);
- fic.insn_bytes = 1;
- asm volatile ( "fwait" ::: "memory" );
+ emulate_fpu_insn_stub(b);
check_fpu_exn(&fic);
break;
@@ -4263,37 +4259,13 @@ x86_emulate(
emulate_fpu_insn_stub(0xd8, modrm);
break;
default:
+ fpu_memsrc32:
ASSERT(ea.type == OP_MEM);
if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
4, ctxt)) != X86EMUL_OKAY )
goto done;
- switch ( modrm_reg & 7 )
- {
- case 0: /* fadd */
- emulate_fpu_insn_memsrc("fadds", src.val);
- break;
- case 1: /* fmul */
- emulate_fpu_insn_memsrc("fmuls", src.val);
- break;
- case 2: /* fcom */
- emulate_fpu_insn_memsrc("fcoms", src.val);
- break;
- case 3: /* fcomp */
- emulate_fpu_insn_memsrc("fcomps", src.val);
- break;
- case 4: /* fsub */
- emulate_fpu_insn_memsrc("fsubs", src.val);
- break;
- case 5: /* fsubr */
- emulate_fpu_insn_memsrc("fsubrs", src.val);
- break;
- case 6: /* fdiv */
- emulate_fpu_insn_memsrc("fdivs", src.val);
- break;
- case 7: /* fdivr */
- emulate_fpu_insn_memsrc("fdivrs", src.val);
- break;
- }
+ emulate_fpu_insn_memsrc(b, modrm_reg, src.val);
+ break;
}
check_fpu_exn(&fic);
break;
@@ -4340,52 +4312,46 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fld m32fp */
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 4, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("flds", src.val);
- dst.type = OP_NONE;
- break;
+ goto fpu_memsrc32;
case 2: /* fst m32fp */
- emulate_fpu_insn_memdst("fsts", dst.val);
- dst.bytes = 4;
- break;
case 3: /* fstp m32fp */
- emulate_fpu_insn_memdst("fstps", dst.val);
+ fpu_memdst32:
+ dst = ea;
dst.bytes = 4;
+ emulate_fpu_insn_memdst(b, modrm_reg, dst.val);
break;
case 4: /* fldenv - TODO */
state->fpu_ctrl = true;
goto cannot_emulate;
case 5: /* fldcw m2byte */
state->fpu_ctrl = true;
+ fpu_memsrc16:
if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
2, ctxt)) != X86EMUL_OKAY )
goto done;
- emulate_fpu_insn_memsrc("fldcw", src.val);
- dst.type = OP_NONE;
+ emulate_fpu_insn_memsrc(b, modrm_reg, src.val);
break;
case 6: /* fnstenv - TODO */
state->fpu_ctrl = true;
goto cannot_emulate;
case 7: /* fnstcw m2byte */
state->fpu_ctrl = true;
- emulate_fpu_insn_memdst("fnstcw", dst.val);
+ fpu_memdst16:
+ dst = ea;
dst.bytes = 2;
+ emulate_fpu_insn_memdst(b, modrm_reg, dst.val);
break;
default:
generate_exception(EXC_UD);
}
/*
* Control instructions can't raise FPU exceptions, so we need
- * to consider suppressing writes only for non-control ones. All
- * of them in this group have data width 4.
+ * to consider suppressing writes only for non-control ones.
*/
- if ( dst.type == OP_MEM && dst.bytes == 4 && !fpu_check_write() )
+ if ( dst.type == OP_MEM && !state->fpu_ctrl && !fpu_check_write() )
dst.type = OP_NONE;
}
check_fpu_exn(&fic);
@@ -4408,36 +4374,7 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 4, ctxt)) != X86EMUL_OKAY )
- goto done;
- switch ( modrm_reg & 7 )
- {
- case 0: /* fiadd m32i */
- emulate_fpu_insn_memsrc("fiaddl", src.val);
- break;
- case 1: /* fimul m32i */
- emulate_fpu_insn_memsrc("fimull", src.val);
- break;
- case 2: /* ficom m32i */
- emulate_fpu_insn_memsrc("ficoml", src.val);
- break;
- case 3: /* ficomp m32i */
- emulate_fpu_insn_memsrc("ficompl", src.val);
- break;
- case 4: /* fisub m32i */
- emulate_fpu_insn_memsrc("fisubl", src.val);
- break;
- case 5: /* fisubr m32i */
- emulate_fpu_insn_memsrc("fisubrl", src.val);
- break;
- case 6: /* fidiv m32i */
- emulate_fpu_insn_memsrc("fidivl", src.val);
- break;
- case 7: /* fidivr m32i */
- emulate_fpu_insn_memsrc("fidivrl", src.val);
- break;
- }
+ goto fpu_memsrc32;
}
check_fpu_exn(&fic);
break;
@@ -4467,50 +4404,35 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fild m32i */
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 4, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("fildl", src.val);
- dst.type = OP_NONE;
- break;
+ goto fpu_memsrc32;
case 1: /* fisttp m32i */
host_and_vcpu_must_have(sse3);
- emulate_fpu_insn_memdst("fisttpl", dst.val);
- dst.bytes = 4;
- break;
+ /* fall through */
case 2: /* fist m32i */
- emulate_fpu_insn_memdst("fistl", dst.val);
- dst.bytes = 4;
- break;
case 3: /* fistp m32i */
- emulate_fpu_insn_memdst("fistpl", dst.val);
- dst.bytes = 4;
- break;
+ goto fpu_memdst32;
case 5: /* fld m80fp */
+ fpu_memsrc80:
if ( (rc = ops->read(ea.mem.seg, ea.mem.off, mmvalp,
10, ctxt)) != X86EMUL_OKAY )
goto done;
- emulate_fpu_insn_memsrc("fldt", *mmvalp);
- dst.type = OP_NONE;
+ emulate_fpu_insn_memsrc(b, modrm_reg, *mmvalp);
break;
case 7: /* fstp m80fp */
+ fpu_memdst80:
fail_if(!ops->write);
- emulate_fpu_insn_memdst("fstpt", *mmvalp);
+ emulate_fpu_insn_memdst(b, modrm_reg, *mmvalp);
if ( fpu_check_write() &&
(rc = ops->write(ea.mem.seg, ea.mem.off, mmvalp,
10, ctxt)) != X86EMUL_OKAY )
goto done;
- dst.type = OP_NONE;
break;
default:
generate_exception(EXC_UD);
}
- if ( dst.type == OP_MEM && !fpu_check_write() )
- dst.type = OP_NONE;
}
check_fpu_exn(&fic);
break;
@@ -4531,37 +4453,13 @@ x86_emulate(
emulate_fpu_insn_stub(0xdc, modrm);
break;
default:
+ fpu_memsrc64:
ASSERT(ea.type == OP_MEM);
if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
8, ctxt)) != X86EMUL_OKAY )
goto done;
- switch ( modrm_reg & 7 )
- {
- case 0: /* fadd m64fp */
- emulate_fpu_insn_memsrc("faddl", src.val);
- break;
- case 1: /* fmul m64fp */
- emulate_fpu_insn_memsrc("fmull", src.val);
- break;
- case 2: /* fcom m64fp */
- emulate_fpu_insn_memsrc("fcoml", src.val);
- break;
- case 3: /* fcomp m64fp */
- emulate_fpu_insn_memsrc("fcompl", src.val);
- break;
- case 4: /* fsub m64fp */
- emulate_fpu_insn_memsrc("fsubl", src.val);
- break;
- case 5: /* fsubr m64fp */
- emulate_fpu_insn_memsrc("fsubrl", src.val);
- break;
- case 6: /* fdiv m64fp */
- emulate_fpu_insn_memsrc("fdivl", src.val);
- break;
- case 7: /* fdivr m64fp */
- emulate_fpu_insn_memsrc("fdivrl", src.val);
- break;
- }
+ emulate_fpu_insn_memsrc(b, modrm_reg, src.val);
+ break;
}
check_fpu_exn(&fic);
break;
@@ -4581,28 +4479,19 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fld m64fp */;
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 8, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("fldl", src.val);
- dst.type = OP_NONE;
- break;
+ goto fpu_memsrc64;
case 1: /* fisttp m64i */
host_and_vcpu_must_have(sse3);
- emulate_fpu_insn_memdst("fisttpll", dst.val);
- dst.bytes = 8;
- break;
+ /* fall through */
case 2: /* fst m64fp */
- emulate_fpu_insn_memdst("fstl", dst.val);
- dst.bytes = 8;
- break;
case 3: /* fstp m64fp */
- emulate_fpu_insn_memdst("fstpl", dst.val);
+ fpu_memdst64:
+ dst = ea;
dst.bytes = 8;
+ emulate_fpu_insn_memdst(b, modrm_reg, dst.val);
break;
case 4: /* frstor - TODO */
case 6: /* fnsave - TODO */
@@ -4610,18 +4499,15 @@ x86_emulate(
goto cannot_emulate;
case 7: /* fnstsw m2byte */
state->fpu_ctrl = true;
- emulate_fpu_insn_memdst("fnstsw", dst.val);
- dst.bytes = 2;
- break;
+ goto fpu_memdst16;
default:
generate_exception(EXC_UD);
}
/*
* Control instructions can't raise FPU exceptions, so we need
- * to consider suppressing writes only for non-control ones. All
- * of them in this group have data width 8.
+ * to consider suppressing writes only for non-control ones.
*/
- if ( dst.type == OP_MEM && dst.bytes == 8 && !fpu_check_write() )
+ if ( dst.type == OP_MEM && !state->fpu_ctrl && !fpu_check_write() )
dst.type = OP_NONE;
}
check_fpu_exn(&fic);
@@ -4644,33 +4530,8 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- switch ( modrm_reg & 7 )
- {
- case 0: /* fiadd m16i */
- emulate_fpu_insn_memsrc("fiadds", src.val);
- break;
- case 1: /* fimul m16i */
- emulate_fpu_insn_memsrc("fimuls", src.val);
- break;
- case 2: /* ficom m16i */
- emulate_fpu_insn_memsrc("ficoms", src.val);
- break;
- case 3: /* ficomp m16i */
- emulate_fpu_insn_memsrc("ficomps", src.val);
- break;
- case 4: /* fisub m16i */
- emulate_fpu_insn_memsrc("fisubs", src.val);
- break;
- case 5: /* fisubr m16i */
- emulate_fpu_insn_memsrc("fisubrs", src.val);
- break;
- case 6: /* fidiv m16i */
- emulate_fpu_insn_memsrc("fidivs", src.val);
- break;
- case 7: /* fidivr m16i */
- emulate_fpu_insn_memsrc("fidivrs", src.val);
- break;
- }
+ emulate_fpu_insn_memsrc(b, modrm_reg, src.val);
+ break;
}
check_fpu_exn(&fic);
break;
@@ -4686,7 +4547,7 @@ x86_emulate(
dst.bytes = 2;
dst.type = OP_REG;
dst.reg = (void *)&_regs.ax;
- emulate_fpu_insn_memdst("fnstsw", dst.val);
+ emulate_fpu_insn_memdst(b, modrm_reg, dst.val);
break;
case 0xe8 ... 0xef: /* fucomip %stN */
case 0xf0 ... 0xf7: /* fcomip %stN */
@@ -4701,59 +4562,26 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fild m16i */
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 2, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("filds", src.val);
- dst.type = OP_NONE;
- break;
+ goto fpu_memsrc16;
case 1: /* fisttp m16i */
host_and_vcpu_must_have(sse3);
- emulate_fpu_insn_memdst("fisttps", dst.val);
- dst.bytes = 2;
- break;
+ /* fall through */
case 2: /* fist m16i */
- emulate_fpu_insn_memdst("fists", dst.val);
- dst.bytes = 2;
- break;
case 3: /* fistp m16i */
- emulate_fpu_insn_memdst("fistps", dst.val);
- dst.bytes = 2;
- break;
+ goto fpu_memdst16;
case 4: /* fbld m80dec */
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, mmvalp,
- 10, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("fbld", *mmvalp);
- dst.type = OP_NONE;
- break;
+ goto fpu_memsrc80;
case 5: /* fild m64i */
- if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- 8, ctxt)) != X86EMUL_OKAY )
- goto done;
- emulate_fpu_insn_memsrc("fildll", src.val);
dst.type = OP_NONE;
- break;
+ goto fpu_memsrc64;
case 6: /* fbstp packed bcd */
- fail_if(!ops->write);
- emulate_fpu_insn_memdst("fbstp", *mmvalp);
- if ( fpu_check_write() &&
- (rc = ops->write(ea.mem.seg, ea.mem.off, mmvalp,
- 10, ctxt)) != X86EMUL_OKAY )
- goto done;
- dst.type = OP_NONE;
- break;
+ goto fpu_memdst80;
case 7: /* fistp m64i */
- emulate_fpu_insn_memdst("fistpll", dst.val);
- dst.bytes = 8;
- break;
+ goto fpu_memdst64;
}
- if ( dst.type == OP_MEM && !fpu_check_write() )
- dst.type = OP_NONE;
}
check_fpu_exn(&fic);
break;
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next prev parent reply other threads:[~2017-09-14 15:21 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-14 14:51 [PATCH v2 00/17] x86: emulator enhancements Jan Beulich
2017-09-14 15:12 ` [PATCH v2 01/17] x86emul: support remaining AVX insns Jan Beulich
2017-10-09 15:36 ` George Dunlap
2017-10-09 16:12 ` Jan Beulich
2017-10-10 14:17 ` George Dunlap
2017-09-14 15:12 ` [PATCH v2 02/17] x86emul: re-order cases of main switch statement Jan Beulich
2017-09-15 17:23 ` Andrew Cooper
2017-09-14 15:13 ` [PATCH v2 03/17] x86emul: build SIMD tests with -Os Jan Beulich
2017-09-14 15:13 ` [PATCH v2 04/17] x86emul: support F16C insns Jan Beulich
2017-09-14 15:14 ` [PATCH v2 05/17] x86emul: support FMA4 insns Jan Beulich
2017-09-14 15:14 ` [PATCH v2 06/17] x86emul: support FMA insns Jan Beulich
2017-09-14 15:15 ` [PATCH v2 07/17] x86emul: support most remaining AVX2 insns Jan Beulich
2017-09-14 15:16 ` [PATCH v2 08/17] x86emul: fold/eliminate some local variables Jan Beulich
2017-09-15 17:22 ` Andrew Cooper
2017-10-06 14:21 ` George Dunlap
2017-10-06 14:47 ` Jan Beulich
2017-10-06 14:43 ` George Dunlap
2017-09-14 15:17 ` [PATCH v2 09/17] x86emul: support AVX2 gather insns Jan Beulich
2017-09-14 15:17 ` [PATCH v2 10/17] x86emul: add tables for XOP 08 and 09 extension spaces Jan Beulich
2017-09-14 15:18 ` [PATCH v2 11/17] x86emul: support XOP insns Jan Beulich
2017-09-14 15:18 ` [PATCH v2 12/17] x86emul: support 3DNow! insns Jan Beulich
2017-09-14 15:19 ` [PATCH v2 13/17] x86emul: re-order checks in test harness Jan Beulich
2017-09-15 17:26 ` Andrew Cooper
2017-09-14 15:20 ` [PATCH v2 14/17] x86emul: abstract out XCRn accesses Jan Beulich
2017-09-14 15:25 ` Jan Beulich
2017-09-18 9:12 ` Paul Durrant
2017-09-14 15:20 ` [PATCH v2 15/17] x86emul: adjust_bnd() should check XCR0 Jan Beulich
2017-09-14 15:21 ` Jan Beulich [this message]
2017-09-14 15:22 ` [PATCH v2 17/17] x86/HVM: eliminate custom #MF/#XM handling Jan Beulich
2017-09-18 9:27 ` Paul Durrant
2017-09-18 9:35 ` Jan Beulich
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