From 045a282ca41505184e8fc805335d1f5aae0c8a03 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 20 Dec 2012 16:57:43 +0200 Subject: [PATCH] KVM: emulator: implement fninit, fnstsw, fnstcw Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 125 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index a3d31e3..53c5ad6 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -115,6 +115,7 @@ #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ +#define Escape (5<<15) /* Escape to coprocessor instruction */ #define Sse (1<<18) /* SSE Vector instruction */ /* Generic ModRM decode. */ #define ModRM (1<<19) @@ -166,6 +167,7 @@ struct opcode { const struct opcode *group; const struct group_dual *gdual; const struct gprefix *gprefix; + const struct escape *esc; } u; int (*check_perm)(struct x86_emulate_ctxt *ctxt); }; @@ -182,6 +184,11 @@ struct gprefix { struct opcode pfx_f3; }; +struct escape { + struct opcode op[8]; + struct opcode high[64]; +}; + /* EFLAGS bit definitions. */ #define EFLG_ID (1<<21) #define EFLG_VIP (1<<20) @@ -991,6 +998,53 @@ static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) ctxt->ops->put_fpu(ctxt); } +static int em_fninit(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + ctxt->ops->get_fpu(ctxt); + asm volatile("fninit"); + ctxt->ops->put_fpu(ctxt); + return X86EMUL_CONTINUE; +} + +static int em_fnstcw(struct x86_emulate_ctxt *ctxt) +{ + u16 fcw; + + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + ctxt->ops->get_fpu(ctxt); + asm volatile("fnstcw %0": "+m"(fcw)); + ctxt->ops->put_fpu(ctxt); + + /* force 2 byte destination */ + ctxt->dst.bytes = 2; + ctxt->dst.val = fcw; + + return X86EMUL_CONTINUE; +} + +static int em_fnstsw(struct x86_emulate_ctxt *ctxt) +{ + u16 fsw; + + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + ctxt->ops->get_fpu(ctxt); + asm volatile("fnstsw %0": "+m"(fsw)); + ctxt->ops->put_fpu(ctxt); + + /* force 2 byte destination */ + ctxt->dst.bytes = 2; + ctxt->dst.val = fsw; + + return X86EMUL_CONTINUE; +} + static void decode_register_operand(struct x86_emulate_ctxt *ctxt, struct operand *op) { @@ -3590,6 +3644,7 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt) #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) } #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) } +#define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) } #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } #define II(_f, _e, _i) \ { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i } @@ -3725,6 +3780,69 @@ static const struct gprefix pfx_vmovntpx = { I(0, em_mov), N, N, N, }; +static const struct escape escape_d9 = { { + N, N, N, N, N, N, N, I(DstMem, em_fnstcw), +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, N, N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + +static const struct escape escape_db = { { + N, N, N, N, N, N, N, N, +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, I(ImplicitOps, em_fninit), N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + +static const struct escape escape_dd = { { + N, N, N, N, N, N, N, I(DstMem, em_fnstsw), +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, N, N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + static const struct opcode opcode_table[256] = { /* 0x00 - 0x07 */ I6ALU(Lock, em_add), @@ -3821,7 +3939,7 @@ static const struct opcode opcode_table[256] = { D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM), N, I(DstAcc | SrcImmByte | No64, em_aad), N, N, /* 0xD8 - 0xDF */ - N, N, N, N, N, N, N, N, + N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, /* 0xE0 - 0xE7 */ X3(I(SrcImmByte, em_loop)), I(SrcImmByte, em_jcxz), @@ -4246,6 +4364,12 @@ done_prefixes: case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; } break; + case Escape: + if (ctxt->modrm > 0xbf) + opcode = opcode.u.esc->high[ctxt->modrm - 0xc0]; + else + opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7]; + break; default: return EMULATION_FAILED; } -- 2.7.4