From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768Ab1IMKr4 (ORCPT ); Tue, 13 Sep 2011 06:47:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26599 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752332Ab1IMKry (ORCPT ); Tue, 13 Sep 2011 06:47:54 -0400 Message-ID: <4E6F34CF.1060302@redhat.com> Date: Tue, 13 Sep 2011 13:47:43 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110816 Thunderbird/6.0 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH v3 03/11] KVM: x86: retry non-page-table writing instruction References: <4E5C4C20.3000403@cn.fujitsu.com> <4E5C4C5C.8030602@cn.fujitsu.com> In-Reply-To: <4E5C4C5C.8030602@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/30/2011 05:35 AM, Xiao Guangrong wrote: > If the emulation is caused by #PF and it is non-page_table writing instruction, > it means the VM-EXIT is caused by shadow page protected, we can zap the shadow > page and retry this instruction directly > > The idea is from Avi > > > int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len); > +bool page_table_writing_insn(struct x86_emulate_ctxt *ctxt); Please use the usual x86_ prefix used in the emulator interface. > @@ -3720,10 +3721,18 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) > kvm_mmu_commit_zap_page(vcpu->kvm,&invalid_list); > } > > +static bool is_mmio_page_fault(struct kvm_vcpu *vcpu, gva_t addr) > +{ > + if (vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu)) > + return vcpu_match_mmio_gpa(vcpu, addr); > + > + return vcpu_match_mmio_gva(vcpu, addr); > +} > + > int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code, > void *insn, int insn_len) > { > - int r; > + int r, emulation_type = EMULTYPE_RETRY; > enum emulation_result er; > > r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code, false); > @@ -3735,7 +3744,10 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code, > goto out; > } > > - er = x86_emulate_instruction(vcpu, cr2, 0, insn, insn_len); > + if (is_mmio_page_fault(vcpu, cr2)) > + emulation_type = 0; > + > + er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len); > > switch (er) { > case EMULATE_DONE: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 6b37f18..1afe59e 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4814,6 +4814,50 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva) > return false; > } > > +static bool retry_instruction(struct x86_emulate_ctxt *ctxt, > + unsigned long cr2, int emulation_type) > +{ > + if (!vcpu->arch.mmu.direct_map&& !mmu_is_nested(vcpu)) > + gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL); If mmu_is_nested() cr2 is an ngpa, we have to translate it to a gpa, no? btw, I don't see mmu.direct_map initialized for nested npt? > + > + kvm_mmu_unprotect_page(vcpu->kvm, gpa>> PAGE_SHIFT); > + > + return true; > +} > + > int x86_emulate_instruction(struct kvm_vcpu *vcpu, > unsigned long cr2, > int emulation_type, > @@ -4855,6 +4899,9 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, > return EMULATE_DONE; > } > > + if (retry_instruction(ctxt, cr2, emulation_type)) > + return EMULATE_DONE; > + > /* this is needed for vmware backdoor interface to work since it > changes registers values during IO operation */ > if (vcpu->arch.emulate_regs_need_sync_from_vcpu) { -- error compiling committee.c: too many arguments to function