From: Wei Yongjun <[email protected]> This patch change to disable writeback when decode dest operand if the dest type is ImplicitOps or not specified.
Signed-off-by: Wei Yongjun <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 9a04504..b49a345 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2628,9 +2628,6 @@ done_prefixes: /* Decode and fetch the destination operand: register or memory. */ switch (c->d & DstMask) { - case ImplicitOps: - /* Special instructions do their own operand decoding. */ - return 0; case DstReg: decode_register_operand(&c->dst, c, c->twobyte && (c->b == 0xb6 || c->b == 0xb7)); @@ -2665,6 +2662,11 @@ done_prefixes: c->regs[VCPU_REGS_RDI]); c->dst.val = 0; break; + case ImplicitOps: + /* Special instructions do their own operand decoding. */ + default: + c->dst.type = OP_NONE; /* Disable writeback. */ + return 0; } done: @@ -3116,7 +3118,6 @@ special_insn: case 0xf5: /* cmc */ /* complement carry flag from eflags reg */ ctxt->eflags ^= EFLG_CF; - c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xf6 ... 0xf7: /* Grp3 */ if (!emulate_grp3(ctxt, ops)) @@ -3124,16 +3125,13 @@ special_insn: break; case 0xf8: /* clc */ ctxt->eflags &= ~EFLG_CF; - c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfa: /* cli */ if (emulator_bad_iopl(ctxt, ops)) { emulate_gp(ctxt, 0); goto done; - } else { + } else ctxt->eflags &= ~X86_EFLAGS_IF; - c->dst.type = OP_NONE; /* Disable writeback. */ - } break; case 0xfb: /* sti */ if (emulator_bad_iopl(ctxt, ops)) { @@ -3142,16 +3140,13 @@ special_insn: } else { ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; ctxt->eflags |= X86_EFLAGS_IF; - c->dst.type = OP_NONE; /* Disable writeback. */ } break; case 0xfc: /* cld */ ctxt->eflags &= ~EFLG_DF; - c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfd: /* std */ ctxt->eflags |= EFLG_DF; - c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfe: /* Grp4 */ grp45: @@ -3288,16 +3283,13 @@ twobyte_insn: break; case 0x06: emulate_clts(ctxt->vcpu); - c->dst.type = OP_NONE; break; case 0x09: /* wbinvd */ kvm_emulate_wbinvd(ctxt->vcpu); - c->dst.type = OP_NONE; break; case 0x08: /* invd */ case 0x0d: /* GrpP (prefetch) */ case 0x18: /* Grp16 (prefetch/nop) */ - c->dst.type = OP_NONE; break; case 0x20: /* mov cr, reg */ switch (c->modrm_reg) { @@ -3350,7 +3342,6 @@ twobyte_insn: goto done; } rc = X86EMUL_CONTINUE; - c->dst.type = OP_NONE; break; case 0x32: /* rdmsr */ @@ -3362,7 +3353,6 @@ twobyte_insn: c->regs[VCPU_REGS_RDX] = msr_data >> 32; } rc = X86EMUL_CONTINUE; - c->dst.type = OP_NONE; break; case 0x34: /* sysenter */ rc = emulate_sysenter(ctxt, ops); @@ -3386,7 +3376,6 @@ twobyte_insn: case 0x80 ... 0x8f: /* jnz rel, etc*/ if (test_cc(c->b, ctxt->eflags)) jmp_rel(c, c->src.val); - c->dst.type = OP_NONE; break; case 0xa0: /* push fs */ emulate_push_sreg(ctxt, ops, VCPU_SREG_FS); -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
