diff options
| author | Gleb Natapov <gleb@redhat.com> | 2012-09-03 15:24:29 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-09-06 18:07:38 +0300 |
| commit | b3356bf0dbb34980620f2f7def7d1b9a0d325225 (patch) | |
| tree | 508f58ece4a7ff5613181584fd0461e7cbfd5d20 /arch/x86/kvm/emulate.c | |
| parent | f3bd64c68a8f1245e3d037f70c6936cd7bb1196b (diff) | |
KVM: emulator: optimize "rep ins" handling
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 <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 415f903facd..39171cb307e 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1301,8 +1301,15 @@ 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; } @@ -1546,6 +1553,14 @@ 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; @@ -2793,7 +2808,7 @@ 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, reg_rmw(ctxt, reg), df * op->bytes); op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, reg)); @@ -3733,7 +3748,7 @@ static const 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)), @@ -3991,6 +4006,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, register_address(ctxt, reg_read(ctxt, VCPU_REGS_RDI)); op->addr.mem.seg = VCPU_SREG_ES; op->val = 0; + op->count = 1; break; case OpDX: op->type = OP_REG; @@ -4034,6 +4050,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSI)); op->addr.mem.seg = seg_override(ctxt); op->val = 0; + op->count = 1; break; case OpImmFAddr: op->type = OP_IMM; @@ -4575,8 +4592,14 @@ 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, reg_rmw(ctxt, VCPU_REGS_RCX), -1); + if ((ctxt->d & SrcMask) == SrcSI) + count = ctxt->src.count; + else + count = ctxt->dst.count; + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), + -count); if (!string_insn_completed(ctxt)) { /* |