diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_emulate.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/emulate.c | 43 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 16 |
3 files changed, 30 insertions, 33 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 1bbf2b6f2a7e..1bf11400ae99 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -224,7 +224,6 @@ struct x86_emulate_ctxt { /* interruptibility state, as a result of execution of STI or MOV SS */ int interruptibility; - bool restart; /* restart string instruction after writeback */ bool perm_ok; /* do not check permissions if true */ int exception; /* exception that happens during emulation or -1 */ @@ -255,6 +254,9 @@ struct x86_emulate_ctxt { #endif int x86_decode_insn(struct x86_emulate_ctxt *ctxt); +#define EMULATION_FAILED -1 +#define EMULATION_OK 0 +#define EMULATION_RESTART 1 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); int emulator_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int reason, diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3dcbc1d0a59d..ec35a71d8b5d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -437,7 +437,6 @@ static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, ctxt->exception = vec; ctxt->error_code = error; ctxt->error_code_valid = valid; - ctxt->restart = false; } static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err) @@ -2633,9 +2632,6 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt) struct opcode opcode, *g_mod012, *g_mod3; struct operand memop = { .type = OP_NONE }; - /* we cannot decode insn before we complete previous rep insn */ - WARN_ON(ctxt->restart); - c->eip = ctxt->eip; c->fetch.start = c->fetch.end = c->eip; ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS); @@ -2985,10 +2981,8 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) } if (c->rep_prefix && (c->d & String)) { - ctxt->restart = true; /* All REP prefixes have the same first termination condition */ if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { - ctxt->restart = false; ctxt->eip = c->eip; goto done; } @@ -3446,28 +3440,29 @@ writeback: struct read_cache *r = &ctxt->decode.io_read; register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); - if (string_insn_completed(ctxt)) - ctxt->restart = false; - /* - * Re-enter guest when pio read ahead buffer is empty or, - * if it is not used, after each 1024 iteration. - */ - else if ((r->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) || - (r->end != 0 && r->end == r->pos)) { - ctxt->restart = false; - c->eip = ctxt->eip; + 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 */ } } - /* - * reset read cache here in case string instruction is restared - * without decoding - */ - ctxt->decode.mem_read.end = 0; - if (!ctxt->restart) - ctxt->eip = c->eip; + + ctxt->eip = c->eip; done: - return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; + return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; twobyte_insn: switch (c->b) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d4d33f943d99..bc96ac9ed912 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4181,18 +4181,17 @@ int emulate_instruction(struct kvm_vcpu *vcpu, restart: r = x86_emulate_insn(&vcpu->arch.emulate_ctxt); - if (r) { /* emulation failed */ + if (r == EMULATION_FAILED) { if (reexecute_instruction(vcpu, cr2)) return EMULATE_DONE; return handle_emulation_failure(vcpu); } - r = EMULATE_DONE; - - if (vcpu->arch.emulate_ctxt.exception >= 0) + if (vcpu->arch.emulate_ctxt.exception >= 0) { inject_emulated_exception(vcpu); - else if (vcpu->arch.pio.count) { + r = EMULATE_DONE; + } else if (vcpu->arch.pio.count) { if (!vcpu->arch.pio.in) vcpu->arch.pio.count = 0; r = EMULATE_DO_MMIO; @@ -4200,8 +4199,10 @@ restart: if (vcpu->mmio_is_write) vcpu->mmio_needed = 0; r = EMULATE_DO_MMIO; - } else if (vcpu->arch.emulate_ctxt.restart) + } else if (r == EMULATION_RESTART) goto restart; + else + r = EMULATE_DONE; toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility); kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags); @@ -5100,8 +5101,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) if (!irqchip_in_kernel(vcpu->kvm)) kvm_set_cr8(vcpu, kvm_run->cr8); - if (vcpu->arch.pio.count || vcpu->mmio_needed || - vcpu->arch.emulate_ctxt.restart) { + if (vcpu->arch.pio.count || vcpu->mmio_needed) { if (vcpu->mmio_needed) { memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8); vcpu->mmio_read_completed = 1; |
