#include "kvm_cache_regs.h"
#include <linux/module.h>
#include <asm/kvm_emulate.h>
+#include <linux/stringify.h>
#include "x86.h"
#include "tss.h"
#define OpCL 9ull /* CL register (for shifts) */
#define OpImmByte 10ull /* 8-bit sign extended immediate */
#define OpOne 11ull /* Implied 1 */
-#define OpImm 12ull /* Sign extended immediate */
+#define OpImm 12ull /* Sign extended up to 32-bit immediate */
#define OpMem16 13ull /* Memory operand (16-bit). */
#define OpMem32 14ull /* Memory operand (32-bit). */
#define OpImmU 15ull /* Immediate operand, zero extended */
#define OpFS 24ull /* FS */
#define OpGS 25ull /* GS */
#define OpMem8 26ull /* 8-bit zero extended memory operand */
+#define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */
#define OpBits 5 /* Width of operand field */
#define OpMask ((1ull << OpBits) - 1)
#define SrcMemFAddr (OpMemFAddr << SrcShift)
#define SrcAcc (OpAcc << SrcShift)
#define SrcImmU16 (OpImmU16 << SrcShift)
+#define SrcImm64 (OpImm64 << SrcShift)
#define SrcDX (OpDX << SrcShift)
#define SrcMem8 (OpMem8 << SrcShift)
#define SrcMask (OpMask << SrcShift)
#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)
#define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */
#define Unaligned ((u64)1 << 42) /* Explicitly unaligned (e.g. MOVDQU) */
#define Avx ((u64)1 << 43) /* Advanced Vector Extensions */
+#define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */
#define X2(x...) x, x
#define X3(x...) X2(x), x
#define X8(x...) X4(x), X4(x)
#define X16(x...) X8(x), X8(x)
+#define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
+#define FASTOP_SIZE 8
+
+/*
+ * fastop functions have a special calling convention:
+ *
+ * dst: [rdx]:rax (in/out)
+ * src: rbx (in/out)
+ * src2: rcx (in)
+ * flags: rflags (in/out)
+ *
+ * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
+ * different operand sizes can be reached by calculation, rather than a jump
+ * table (which would be bigger than the code).
+ *
+ * fastop functions are declared as taking a never-defined fastop parameter,
+ * so they can't be called from C directly.
+ */
+
+struct fastop;
+
struct opcode {
u64 flags : 56;
u64 intercept : 8;
const struct opcode *group;
const struct group_dual *gdual;
const struct gprefix *gprefix;
+ const struct escape *esc;
+ void (*fastop)(struct fastop *fake);
} u;
int (*check_perm)(struct x86_emulate_ctxt *ctxt);
};
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)
} \
} while (0)
+#define FOP_ALIGN ".align " __stringify(FASTOP_SIZE) " \n\t"
+#define FOP_RET "ret \n\t"
+
+#define FOP_START(op) \
+ extern void em_##op(struct fastop *fake); \
+ asm(".pushsection .text, \"ax\" \n\t" \
+ ".global em_" #op " \n\t" \
+ FOP_ALIGN \
+ "em_" #op ": \n\t"
+
+#define FOP_END \
+ ".popsection")
+
+#define FOP1E(op, dst) \
+ FOP_ALIGN #op " %" #dst " \n\t" FOP_RET
+
+#define FASTOP1(op) \
+ FOP_START(op) \
+ FOP1E(op##b, al) \
+ FOP1E(op##w, ax) \
+ FOP1E(op##l, eax) \
+ ON64(FOP1E(op##q, rax)) \
+ FOP_END
+
#define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \
do { \
unsigned long _tmp; \
ulong la;
u32 lim;
u16 sel;
- unsigned cpl, rpl;
+ unsigned cpl;
la = seg_base(ctxt, addr.seg) + addr.ea;
switch (ctxt->mode) {
addr.seg);
if (!usable)
goto bad;
- /* code segment or read-only data segment */
- if (((desc.type & 8) || !(desc.type & 2)) && write)
+ /* code segment in protected mode or read-only data segment */
+ if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8))
+ || !(desc.type & 2)) && write)
goto bad;
/* unreadable code segment */
if (!fetch && (desc.type & 8) && !(desc.type & 2))
goto bad;
}
cpl = ctxt->ops->cpl(ctxt);
- if (ctxt->mode == X86EMUL_MODE_REAL)
- rpl = 0;
- else
- rpl = sel & 3;
- cpl = max(cpl, rpl);
if (!(desc.type & 8)) {
/* data segment */
if (cpl > desc.dpl)
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)
{
return X86EMUL_CONTINUE;
}
+static int em_aad(struct x86_emulate_ctxt *ctxt)
+{
+ u8 al = ctxt->dst.val & 0xff;
+ u8 ah = (ctxt->dst.val >> 8) & 0xff;
+
+ al = (al + (ah * ctxt->src.val)) & 0xff;
+
+ ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al;
+
+ ctxt->eflags &= ~(X86_EFLAGS_PF | X86_EFLAGS_SF | X86_EFLAGS_ZF);
+
+ if (!al)
+ ctxt->eflags |= X86_EFLAGS_ZF;
+ if (!(al & 1))
+ ctxt->eflags |= X86_EFLAGS_PF;
+ if (al & 0x80)
+ ctxt->eflags |= X86_EFLAGS_SF;
+
+ return X86EMUL_CONTINUE;
+}
+
static int em_call(struct x86_emulate_ctxt *ctxt)
{
long rel = ctxt->src.val;
#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 F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) }
#define II(_f, _e, _i) \
{ .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i }
#define IIP(_f, _e, _i, _p) \
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),
/* 0xB0 - 0xB7 */
X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
/* 0xB8 - 0xBF */
- X8(I(DstReg | SrcImm | Mov, em_mov)),
+ X8(I(DstReg | SrcImm64 | Mov, em_mov)),
/* 0xC0 - 0xC7 */
D2bv(DstMem | SrcImmByte | ModRM),
I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
/* 0xD0 - 0xD7 */
D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM),
- N, N, N, N,
+ 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),
case 4:
op->val = insn_fetch(s32, ctxt);
break;
+ case 8:
+ op->val = insn_fetch(s64, ctxt);
+ break;
}
if (!sign_extension) {
switch (op->bytes) {
case OpImm:
rc = decode_imm(ctxt, op, imm_size(ctxt), true);
break;
+ case OpImm64:
+ rc = decode_imm(ctxt, op, ctxt->op_bytes, true);
+ break;
case OpMem8:
ctxt->memop.bytes = 1;
goto mem_common;
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;
}
read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
}
+static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
+{
+ ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF;
+ fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE;
+ asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n"
+ : "+a"(ctxt->dst.val), "+b"(ctxt->src.val), [flags]"+D"(flags)
+ : "c"(ctxt->src2.val), [fastop]"S"(fop));
+ ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);
+ return X86EMUL_CONTINUE;
+}
int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
{
}
if (ctxt->execute) {
+ if (ctxt->d & Fastop) {
+ void (*fop)(struct fastop *) = (void *)ctxt->execute;
+ rc = fastop(ctxt, fop);
+ if (rc != X86EMUL_CONTINUE)
+ goto done;
+ goto writeback;
+ }
rc = ctxt->execute(ctxt);
if (rc != X86EMUL_CONTINUE)
goto done;
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