diff options
| -rw-r--r-- | arch/x86/kvm/emulate.c | 146 |
1 files changed, 87 insertions, 59 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 58172fb..6a6aed9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -29,6 +29,22 @@ #include "tss.h" /* + * Operand types + */ +#define OpNone 0 +#define OpImplicit 1 /* No generic decode */ +#define OpReg 2 /* Register */ +#define OpMem 3 /* Memory */ +#define OpAcc 4 /* Accumulator: AL/AX/EAX/RAX */ +#define OpDI 5 /* ES:DI/EDI/RDI */ +#define OpMem64 6 /* Memory, 64-bit */ +#define OpImmUByte 7 /* Zero-extended 8-bit immediate */ +#define OpDX 8 /* DX register */ + +#define OpBits 4 /* Width of operand field */ +#define OpMask ((1 << OpBits) - 1) + +/* * Opcode effective-address decode tables. * Note that we only emulate instructions that have at least one memory * operand (excluding implicit stack references). We assume that stack @@ -40,15 +56,16 @@ /* Operand sizes: 8-bit operands or specified/overridden size. */ #define ByteOp (1<<0) /* 8-bit operands. */ /* Destination operand type. */ -#define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */ -#define DstReg (2<<1) /* Register operand. */ -#define DstMem (3<<1) /* Memory operand. */ -#define DstAcc (4<<1) /* Destination Accumulator */ -#define DstDI (5<<1) /* Destination is in ES:(E)DI */ -#define DstMem64 (6<<1) /* 64bit memory operand */ -#define DstImmUByte (7<<1) /* 8-bit unsigned immediate operand */ -#define DstDX (8<<1) /* Destination is in DX register */ -#define DstMask (0xf<<1) +#define DstShift 1 +#define ImplicitOps (OpImplicit << DstShift) +#define DstReg (OpReg << DstShift) +#define DstMem (OpMem << DstShift) +#define DstAcc (OpAcc << DstShift) +#define DstDI (OpDI << DstShift) +#define DstMem64 (OpMem64 << DstShift) +#define DstImmUByte (OpImmUByte << DstShift) +#define DstDX (OpDX << DstShift) +#define DstMask (OpMask << DstShift) /* Source operand type. */ #define SrcNone (0<<5) /* No source operand. */ #define SrcReg (1<<5) /* Register operand. */ @@ -3316,6 +3333,66 @@ done: return rc; } +static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, + unsigned d) +{ + int rc = X86EMUL_CONTINUE; + + switch (d) { + case OpReg: + decode_register_operand(ctxt, op, + ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7)); + break; + case OpImmUByte: + op->type = OP_IMM; + op->addr.mem.ea = ctxt->_eip; + op->bytes = 1; + op->val = insn_fetch(u8, ctxt); + break; + case OpMem: + case OpMem64: + *op = ctxt->memop; + ctxt->memopp = op; + if (d == OpMem64) + op->bytes = 8; + else + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + if (ctxt->d & BitOp) + fetch_bit_operand(ctxt); + op->orig_val = op->val; + break; + case OpAcc: + op->type = OP_REG; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.reg = &ctxt->regs[VCPU_REGS_RAX]; + fetch_register_operand(op); + op->orig_val = op->val; + break; + case OpDI: + op->type = OP_MEM; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.mem.ea = + register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]); + op->addr.mem.seg = VCPU_SREG_ES; + op->val = 0; + break; + case OpDX: + op->type = OP_REG; + op->bytes = 2; + op->addr.reg = &ctxt->regs[VCPU_REGS_RDX]; + fetch_register_operand(op); + break; + case OpImplicit: + /* Special instructions do their own operand decoding. */ + default: + op->type = OP_NONE; /* Disable writeback. */ + break; + } + +done: + return rc; +} + int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) { int rc = X86EMUL_CONTINUE; @@ -3602,56 +3679,7 @@ done_prefixes: goto done; /* Decode and fetch the destination operand: register or memory. */ - switch (ctxt->d & DstMask) { - case DstReg: - decode_register_operand(ctxt, &ctxt->dst, - ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7)); - break; - case DstImmUByte: - ctxt->dst.type = OP_IMM; - ctxt->dst.addr.mem.ea = ctxt->_eip; - ctxt->dst.bytes = 1; - ctxt->dst.val = insn_fetch(u8, ctxt); - break; - case DstMem: - case DstMem64: - ctxt->dst = ctxt->memop; - ctxt->memopp = &ctxt->dst; - if ((ctxt->d & DstMask) == DstMem64) - ctxt->dst.bytes = 8; - else - ctxt->dst.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - if (ctxt->d & BitOp) - fetch_bit_operand(ctxt); - ctxt->dst.orig_val = ctxt->dst.val; - break; - case DstAcc: - ctxt->dst.type = OP_REG; - ctxt->dst.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - ctxt->dst.addr.reg = &ctxt->regs[VCPU_REGS_RAX]; - fetch_register_operand(&ctxt->dst); - ctxt->dst.orig_val = ctxt->dst.val; - break; - case DstDI: - ctxt->dst.type = OP_MEM; - ctxt->dst.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - ctxt->dst.addr.mem.ea = - register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]); - ctxt->dst.addr.mem.seg = VCPU_SREG_ES; - ctxt->dst.val = 0; - break; - case DstDX: - ctxt->dst.type = OP_REG; - ctxt->dst.bytes = 2; - ctxt->dst.addr.reg = &ctxt->regs[VCPU_REGS_RDX]; - fetch_register_operand(&ctxt->dst); - break; - case ImplicitOps: - /* Special instructions do their own operand decoding. */ - default: - ctxt->dst.type = OP_NONE; /* Disable writeback. */ - break; - } + rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); done: if (ctxt->memopp && ctxt->memopp->type == OP_MEM && ctxt->rip_relative) |
