From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Yongjun Subject: [PATCH 2/4] KVM: x86 emulator: disable writeback when decode dest operand Date: Wed, 04 Aug 2010 15:38:18 +0800 Message-ID: <4C5918EA.7020905@cn.fujitsu.com> References: <4C591895.5040505@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit To: Avi Kivity , kvm@vger.kernel.org Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:56755 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932599Ab0HDHkU (ORCPT ); Wed, 4 Aug 2010 03:40:20 -0400 In-Reply-To: <4C591895.5040505@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: This patch change to disable writeback when decode dest operand if the dest type is ImplicitOps or not specified. Signed-off-by: Wei Yongjun --- arch/x86/kvm/emulate.c | 23 ++++++----------------- 1 files changed, 6 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 4624b11..31c33f4 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2569,9 +2569,6 @@ 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)); @@ -2606,6 +2603,11 @@ 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: @@ -3040,7 +3042,6 @@ 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)) @@ -3048,16 +3049,13 @@ 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)) { @@ -3066,16 +3064,13 @@ 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: @@ -3212,16 +3207,13 @@ 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) { @@ -3274,7 +3266,6 @@ twobyte_insn: goto done; } rc = X86EMUL_CONTINUE; - c->dst.type = OP_NONE; break; case 0x32: /* rdmsr */ @@ -3286,7 +3277,6 @@ 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); @@ -3310,7 +3300,6 @@ 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); -- 1.7.0.4