From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753948AbdF0WkY (ORCPT ); Tue, 27 Jun 2017 18:40:24 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:35717 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751900AbdF0WkR (ORCPT ); Tue, 27 Jun 2017 18:40:17 -0400 MIME-Version: 1.0 In-Reply-To: References: <1498528021-5115-1-git-send-email-wanpeng.li@hotmail.com> <1498528021-5115-3-git-send-email-wanpeng.li@hotmail.com> From: Wanpeng Li Date: Wed, 28 Jun 2017 06:40:15 +0800 Message-ID: Subject: Re: [PATCH v5 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler To: Paolo Bonzini Cc: "linux-kernel@vger.kernel.org" , kvm , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Wanpeng Li Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v5RMeXj0008848 2017-06-27 21:30 GMT+08:00 Paolo Bonzini : > > > 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)? Agreed. > >> /* 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). Agreed. :) Regards, Wanpeng Li