Optimize "rep ins" by allowing emulator to write back more than one datum at a time. Introduce new operand type OP_MEM_STR which tells writeback() that dst contains pointer to an array that should be written back as opposite to just one data element.
Signed-off-by: Gleb Natapov <[email protected]> --- arch/x86/include/asm/kvm_emulate.h | 4 +++- arch/x86/kvm/emulate.c | 33 ++++++++++++++++++++++++++++----- 2 files changed, 31 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 8d0fe8f..d1777f8 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -200,8 +200,9 @@ typedef u32 __attribute__((vector_size(16))) sse128_t; /* Type, address-of, and value of an instruction's operand. */ struct operand { - enum { OP_REG, OP_MEM, OP_IMM, OP_XMM, OP_MM, OP_NONE } type; + enum { OP_REG, OP_MEM, OP_MEM_STR, OP_IMM, OP_XMM, OP_MM, OP_NONE } type; unsigned int bytes; + unsigned int count; union { unsigned long orig_val; u64 orig_val64; @@ -221,6 +222,7 @@ struct operand { char valptr[sizeof(unsigned long) + 2]; sse128_t vec_val; u64 mm_val; + void *data; }; }; diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index c22762d..c74bce8 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1251,8 +1251,15 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, rc->end = n * size; } - memcpy(dest, rc->data + rc->pos, size); - rc->pos += size; + if (ctxt->rep_prefix && !(ctxt->eflags & EFLG_DF)) { + ctxt->dst.data = rc->data + rc->pos; + ctxt->dst.type = OP_MEM_STR; + ctxt->dst.count = (rc->end - rc->pos) / size; + rc->pos = rc->end; + } else { + memcpy(dest, rc->data + rc->pos, size); + rc->pos += size; + } return 1; } @@ -1500,6 +1507,14 @@ static int writeback(struct x86_emulate_ctxt *ctxt) if (rc != X86EMUL_CONTINUE) return rc; break; + case OP_MEM_STR: + rc = segmented_write(ctxt, + ctxt->dst.addr.mem, + ctxt->dst.data, + ctxt->dst.bytes * ctxt->dst.count); + if (rc != X86EMUL_CONTINUE) + return rc; + break; case OP_XMM: write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm); break; @@ -2732,7 +2747,7 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg, struct operand *op) { - int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; + int df = (ctxt->eflags & EFLG_DF) ? -op->count : op->count; register_address_increment(ctxt, &ctxt->regs[reg], df * op->bytes); op->addr.mem.ea = register_address(ctxt, ctxt->regs[reg]); @@ -3672,7 +3687,7 @@ static struct opcode opcode_table[256] = { I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), I(SrcImmByte | Mov | Stack, em_push), I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), - I2bvIP(DstDI | SrcDX | Mov | String, em_in, ins, check_perm_in), /* insb, insw/insd */ + I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ /* 0x70 - 0x7F */ X16(D(SrcImmByte)), @@ -3930,6 +3945,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]); op->addr.mem.seg = VCPU_SREG_ES; op->val = 0; + op->count = 1; break; case OpDX: op->type = OP_REG; @@ -3973,6 +3989,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, register_address(ctxt, ctxt->regs[VCPU_REGS_RSI]); op->addr.mem.seg = seg_override(ctxt); op->val = 0; + op->count = 1; break; case OpImmFAddr: op->type = OP_IMM; @@ -4513,8 +4530,14 @@ writeback: string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst); if (ctxt->rep_prefix && (ctxt->d & String)) { + unsigned int count; struct read_cache *r = &ctxt->io_read; - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1); + if ((ctxt->d & SrcMask) == SrcSI) + count = ctxt->src.count; + else + count = ctxt->dst.count; + register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], + -count); if (!string_insn_completed(ctxt)) { /* -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
