From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753165AbdF0NbB (ORCPT ); Tue, 27 Jun 2017 09:31:01 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:35081 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751605AbdF0Nax (ORCPT ); Tue, 27 Jun 2017 09:30:53 -0400 Subject: Re: [PATCH v5 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler To: Wanpeng Li , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Wanpeng Li References: <1498528021-5115-1-git-send-email-wanpeng.li@hotmail.com> <1498528021-5115-3-git-send-email-wanpeng.li@hotmail.com> From: Paolo Bonzini Message-ID: Date: Tue, 27 Jun 2017 15:30:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <1498528021-5115-3-git-send-email-wanpeng.li@hotmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/06/2017 03:46, Wanpeng Li wrote: > From: Wanpeng Li > > This patch adds the L1 guest async page fault #PF vmexit handler, such > #PF is converted into vmexit from L2 to L1 on #PF which is then handled > by L1 similar to ordinary async page fault. > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Signed-off-by: Wanpeng Li > --- > arch/x86/kvm/vmx.c | 34 ++++++++++++++++++++++++++++------ > 1 file changed, 28 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index df825bb..f533cc1 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -616,6 +616,7 @@ struct vcpu_vmx { > bool emulation_required; > > u32 exit_reason; > + u32 apf_reason; Can you instead of move vcpu_svm's apf_reason field to kvm_vcpu_arch? (e.g. vcpu->arch.apf.host_apf_reason)? > /* Posted interrupt descriptor */ > struct pi_desc pi_desc; > @@ -5648,14 +5649,31 @@ static int handle_exception(struct kvm_vcpu *vcpu) > } > > if (is_page_fault(intr_info)) { > - /* EPT won't cause page fault directly */ > - BUG_ON(enable_ept); > cr2 = vmcs_readl(EXIT_QUALIFICATION); > - trace_kvm_page_fault(cr2, error_code); > + switch (vmx->apf_reason) { > + default: > + /* EPT won't cause page fault directly */ > + BUG_ON(enable_ept); > + trace_kvm_page_fault(cr2, error_code); > > - if (kvm_event_needs_reinjection(vcpu)) > - kvm_mmu_unprotect_page_virt(vcpu, cr2); > - return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0); > + if (kvm_event_needs_reinjection(vcpu)) > + kvm_mmu_unprotect_page_virt(vcpu, cr2); > + return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0); > + break; > + case KVM_PV_REASON_PAGE_NOT_PRESENT: > + vmx->apf_reason = 0; > + local_irq_disable(); > + kvm_async_pf_task_wait(cr2); > + local_irq_enable(); > + break; > + case KVM_PV_REASON_PAGE_READY: > + vmx->apf_reason = 0; > + local_irq_disable(); > + kvm_async_pf_task_wake(cr2); > + local_irq_enable(); > + break; > + } > + return 0; > } This code can be moved to a common function int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, u64 fault_address); in mmu.c. It can be used by vmx.c here and in svm.c's pf_interception. You can change "enable_ept" to "tdp_enabled" (but please make that a WARN_ON_ONCE, too). Thanks, Paolo