This patch is the second part of a work which tries to split x86_emulate_insn() into a few meaningful functions: just encapsulates the switch statement for the two byte instruction emulation as emulate_twobyte_insn().
Signed-off-by: Takuya Yoshikawa <[email protected]> --- arch/x86/kvm/emulate.c | 286 ++++++++++++++++++++++++++---------------------- 1 files changed, 153 insertions(+), 133 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 18d7c07..7aa93df 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3309,142 +3309,14 @@ cannot_emulate: return X86EMUL_UNHANDLEABLE; } -int -x86_emulate_insn(struct x86_emulate_ctxt *ctxt) +static int emulate_twobyte_insn(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, + struct decode_cache *c, + bool *need_writeback) { - struct x86_emulate_ops *ops = ctxt->ops; - u64 msr_data; - struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; - int saved_dst_type = c->dst.type; - bool need_writeback; - - ctxt->decode.mem_read.pos = 0; - - if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { - rc = emulate_ud(ctxt); - goto done; - } - - /* LOCK prefix is allowed only with some instructions */ - if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { - rc = emulate_ud(ctxt); - goto done; - } - - if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) { - rc = emulate_ud(ctxt); - goto done; - } - - /* Privileged instruction can be executed only in CPL=0 */ - if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) { - rc = emulate_gp(ctxt, 0); - goto done; - } - - if (c->rep_prefix && (c->d & String)) { - /* All REP prefixes have the same first termination condition */ - if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { - ctxt->eip = c->eip; - goto done; - } - } - - if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) { - rc = read_emulated(ctxt, ops, linear(ctxt, c->src.addr.mem), - c->src.valptr, c->src.bytes); - if (rc != X86EMUL_CONTINUE) - goto done; - c->src.orig_val64 = c->src.val64; - } - - if (c->src2.type == OP_MEM) { - rc = read_emulated(ctxt, ops, linear(ctxt, c->src2.addr.mem), - &c->src2.val, c->src2.bytes); - if (rc != X86EMUL_CONTINUE) - goto done; - } - - if ((c->d & DstMask) == ImplicitOps) - goto special_insn; - - - if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { - /* optimisation - avoid slow emulated read if Mov */ - rc = read_emulated(ctxt, ops, linear(ctxt, c->dst.addr.mem), - &c->dst.val, c->dst.bytes); - if (rc != X86EMUL_CONTINUE) - goto done; - } - c->dst.orig_val = c->dst.val; - -special_insn: - - if (c->execute) { - rc = c->execute(ctxt); - if (rc != X86EMUL_CONTINUE) - goto done; - goto writeback; - } - - if (c->twobyte) - goto twobyte_insn; - - rc = emulate_onebyte_insn(ctxt, ops, c, &need_writeback); - if (!need_writeback) - goto done; - -writeback: - rc = writeback(ctxt, ops); - if (rc != X86EMUL_CONTINUE) - goto done; - - /* - * restore dst type in case the decoding will be reused - * (happens for string instruction ) - */ - c->dst.type = saved_dst_type; - - if ((c->d & SrcMask) == SrcSI) - string_addr_inc(ctxt, seg_override(ctxt, ops, c), - VCPU_REGS_RSI, &c->src); - - if ((c->d & DstMask) == DstDI) - string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI, - &c->dst); - - if (c->rep_prefix && (c->d & String)) { - struct read_cache *r = &ctxt->decode.io_read; - register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); - - if (!string_insn_completed(ctxt)) { - /* - * Re-enter guest when pio read ahead buffer is empty - * or, if it is not used, after each 1024 iteration. - */ - if ((r->end != 0 || c->regs[VCPU_REGS_RCX] & 0x3ff) && - (r->end == 0 || r->end != r->pos)) { - /* - * Reset read cache. Usually happens before - * decode, but since instruction is restarted - * we have to do it here. - */ - ctxt->decode.mem_read.end = 0; - return EMULATION_RESTART; - } - goto done; /* skip rip writeback */ - } - } - - ctxt->eip = c->eip; - -done: - if (rc == X86EMUL_PROPAGATE_FAULT) - ctxt->have_exception = true; - return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; + u64 msr_data; -twobyte_insn: switch (c->b) { case 0x01: /* lgdt, lidt, lmsw */ switch (c->modrm_reg) { @@ -3748,9 +3620,157 @@ twobyte_insn: goto cannot_emulate; } + *need_writeback = (rc == X86EMUL_CONTINUE); + return rc; + +done: + *need_writeback = false; + return rc; + +cannot_emulate: + *need_writeback = false; + return X86EMUL_UNHANDLEABLE; +} + +int +x86_emulate_insn(struct x86_emulate_ctxt *ctxt) +{ + struct x86_emulate_ops *ops = ctxt->ops; + struct decode_cache *c = &ctxt->decode; + int rc = X86EMUL_CONTINUE; + int saved_dst_type = c->dst.type; + bool need_writeback; + + ctxt->decode.mem_read.pos = 0; + + if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { + rc = emulate_ud(ctxt); + goto done; + } + + /* LOCK prefix is allowed only with some instructions */ + if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { + rc = emulate_ud(ctxt); + goto done; + } + + if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) { + rc = emulate_ud(ctxt); + goto done; + } + + /* Privileged instruction can be executed only in CPL=0 */ + if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) { + rc = emulate_gp(ctxt, 0); + goto done; + } + + if (c->rep_prefix && (c->d & String)) { + /* All REP prefixes have the same first termination condition */ + if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { + ctxt->eip = c->eip; + goto done; + } + } + + if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) { + rc = read_emulated(ctxt, ops, linear(ctxt, c->src.addr.mem), + c->src.valptr, c->src.bytes); + if (rc != X86EMUL_CONTINUE) + goto done; + c->src.orig_val64 = c->src.val64; + } + + if (c->src2.type == OP_MEM) { + rc = read_emulated(ctxt, ops, linear(ctxt, c->src2.addr.mem), + &c->src2.val, c->src2.bytes); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + if ((c->d & DstMask) == ImplicitOps) + goto special_insn; + + + if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { + /* optimisation - avoid slow emulated read if Mov */ + rc = read_emulated(ctxt, ops, linear(ctxt, c->dst.addr.mem), + &c->dst.val, c->dst.bytes); + if (rc != X86EMUL_CONTINUE) + goto done; + } + c->dst.orig_val = c->dst.val; + +special_insn: + + if (c->execute) { + rc = c->execute(ctxt); + if (rc != X86EMUL_CONTINUE) + goto done; + goto writeback; + } + + if (c->twobyte) + goto twobyte_insn; + + rc = emulate_onebyte_insn(ctxt, ops, c, &need_writeback); + if (!need_writeback) + goto done; + +writeback: + rc = writeback(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; + /* + * restore dst type in case the decoding will be reused + * (happens for string instruction ) + */ + c->dst.type = saved_dst_type; + + if ((c->d & SrcMask) == SrcSI) + string_addr_inc(ctxt, seg_override(ctxt, ops, c), + VCPU_REGS_RSI, &c->src); + + if ((c->d & DstMask) == DstDI) + string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI, + &c->dst); + + if (c->rep_prefix && (c->d & String)) { + struct read_cache *r = &ctxt->decode.io_read; + register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); + + if (!string_insn_completed(ctxt)) { + /* + * Re-enter guest when pio read ahead buffer is empty + * or, if it is not used, after each 1024 iteration. + */ + if ((r->end != 0 || c->regs[VCPU_REGS_RCX] & 0x3ff) && + (r->end == 0 || r->end != r->pos)) { + /* + * Reset read cache. Usually happens before + * decode, but since instruction is restarted + * we have to do it here. + */ + ctxt->decode.mem_read.end = 0; + return EMULATION_RESTART; + } + goto done; /* skip rip writeback */ + } + } + + ctxt->eip = c->eip; + +done: + if (rc == X86EMUL_PROPAGATE_FAULT) + ctxt->have_exception = true; + return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; + +twobyte_insn: + rc = emulate_twobyte_insn(ctxt, ops, c, &need_writeback); + if (!need_writeback) + goto done; + goto writeback; cannot_emulate: -- 1.7.1 -- 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
