Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752113AbdF1M02 (ORCPT ); Wed, 28 Jun 2017 08:26:28 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:33456 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751810AbdF1MZb (ORCPT ); Wed, 28 Jun 2017 08:25:31 -0400 From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Wanpeng Li Subject: [PATCH v6 4/4] KVM: async_pf: Let host know whether the guest support delivery async_pf as #PF vmexit Date: Wed, 28 Jun 2017 05:25:12 -0700 Message-Id: <1498652712-10283-5-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498652712-10283-1-git-send-email-wanpeng.li@hotmail.com> References: <1498652712-10283-1-git-send-email-wanpeng.li@hotmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4867 Lines: 130 From: Wanpeng Li Adds another flag bit (bit 2) to MSR_KVM_ASYNC_PF_EN. If bit 2 is 1, async page faults are delivered to L1 as #PF vmexits; if bit 2 is 0, kvm_can_do_async_pf returns 0 if in guest mode. Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li --- Documentation/virtual/kvm/msr.txt | 5 +++-- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/uapi/asm/kvm_para.h | 1 + arch/x86/kernel/kvm.c | 7 ++++++- arch/x86/kvm/mmu.c | 2 +- arch/x86/kvm/vmx.c | 2 +- arch/x86/kvm/x86.c | 5 +++-- 7 files changed, 16 insertions(+), 7 deletions(-) diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt index 0a9ea51..1ebecc1 100644 --- a/Documentation/virtual/kvm/msr.txt +++ b/Documentation/virtual/kvm/msr.txt @@ -166,10 +166,11 @@ MSR_KVM_SYSTEM_TIME: 0x12 MSR_KVM_ASYNC_PF_EN: 0x4b564d02 data: Bits 63-6 hold 64-byte aligned physical address of a 64 byte memory area which must be in guest RAM and must be - zeroed. Bits 5-2 are reserved and should be zero. Bit 0 is 1 + zeroed. Bits 5-3 are reserved and should be zero. Bit 0 is 1 when asynchronous page faults are enabled on the vcpu 0 when disabled. Bit 1 is 1 if asynchronous page faults can be injected - when vcpu is in cpl == 0. + when vcpu is in cpl == 0. Bit 2 is 1 if asynchronous page faults + are delivered to L1 as #PF vmexits. First 4 byte of 64 byte memory location will be written to by the hypervisor at the time of asynchronous page fault (APF) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 71aef4b..a981ab8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -648,6 +648,7 @@ struct kvm_vcpu_arch { bool send_user_only; u32 host_apf_reason; unsigned long nested_apf_token; + bool delivery_as_pf_vmexit; } apf; /* OSVW MSRs (AMD only) */ diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index cff0bb6..a965e5b 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -67,6 +67,7 @@ struct kvm_clock_pairing { #define KVM_ASYNC_PF_ENABLED (1 << 0) #define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1) +#define KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT (1 << 2) /* Operations for KVM_HC_MMU_OP */ #define KVM_MMU_OP_WRITE_PTE 1 diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 43e10d6..71c17a5 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -330,7 +330,12 @@ static void kvm_guest_cpu_init(void) #ifdef CONFIG_PREEMPT pa |= KVM_ASYNC_PF_SEND_ALWAYS; #endif - wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED); + pa |= KVM_ASYNC_PF_ENABLED; + + /* Async page fault support for L1 hypervisor is optional */ + if (wrmsr_safe(MSR_KVM_ASYNC_PF_EN, + (pa | KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT) & 0xffffffff, pa >> 32) < 0) + wrmsrl(MSR_KVM_ASYNC_PF_EN, pa); __this_cpu_write(apf_reason.enabled, 1); printk(KERN_INFO"KVM setup async PF for cpu %d\n", smp_processor_id()); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 4a7dc00..fb8c35f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3705,7 +3705,7 @@ bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu) kvm_event_needs_reinjection(vcpu))) return false; - if (is_guest_mode(vcpu)) + if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu)) return false; return kvm_x86_ops->interrupt_allowed(vcpu); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8724ea6..4f616db 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8001,7 +8001,7 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) if (is_nmi(intr_info)) return false; else if (is_page_fault(intr_info)) - return enable_ept; + return !vmx->vcpu.arch.apf.host_apf_reason && enable_ept; else if (is_no_device(intr_info) && !(vmcs12->guest_cr0 & X86_CR0_TS)) return false; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5756811..7254a11 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2065,8 +2065,8 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) { gpa_t gpa = data & ~0x3f; - /* Bits 2:5 are reserved, Should be zero */ - if (data & 0x3c) + /* Bits 3:5 are reserved, Should be zero */ + if (data & 0x38) return 1; vcpu->arch.apf.msr_val = data; @@ -2082,6 +2082,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) return 1; vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS); + vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT; kvm_async_pf_wakeup_all(vcpu); return 0; } -- 2.7.4