From adfe20fb48785dd73af3bf91407196eb5403c8cf Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Thu, 13 Jul 2017 18:30:41 -0700 Subject: [PATCH] KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add an nested_apf field to vcpu->arch.exception to identify an async page fault, and constructs the expected vm-exit information fields. Force a nested VM exit from nested_vmx_check_exception() if the injected #PF is async page fault. Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_emulate.h | 1 + arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/svm.c | 16 ++++++++++------ arch/x86/kvm/vmx.c | 17 ++++++++++++++--- arch/x86/kvm/x86.c | 9 ++++++++- 5 files changed, 35 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 722d0e568863..fde36f189836 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -23,6 +23,7 @@ struct x86_exception { u16 error_code; bool nested_page_fault; u64 address; /* cr2 or nested page fault gpa */ + u8 async_page_fault; }; /* diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4f20ee6c79a1..5e9ac508f718 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -550,6 +550,7 @@ struct kvm_vcpu_arch { bool reinject; u8 nr; u32 error_code; + u8 nested_apf; } exception; struct kvm_queued_interrupt { @@ -651,6 +652,7 @@ struct kvm_vcpu_arch { u32 id; bool send_user_only; u32 host_apf_reason; + unsigned long nested_apf_token; } apf; /* OSVW MSRs (AMD only) */ diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index fb23497cf915..4d8141e533c3 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2423,15 +2423,19 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, if (!is_guest_mode(&svm->vcpu)) return 0; + vmexit = nested_svm_intercept(svm); + if (vmexit != NESTED_EXIT_DONE) + return 0; + svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr; svm->vmcb->control.exit_code_hi = 0; svm->vmcb->control.exit_info_1 = error_code; - svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2; - - vmexit = nested_svm_intercept(svm); - if (vmexit == NESTED_EXIT_DONE) - svm->nested.exit_required = true; + if (svm->vcpu.arch.exception.nested_apf) + svm->vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token; + else + svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2; + svm->nested.exit_required = true; return vmexit; } @@ -2653,7 +2657,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm) } /* async page fault always cause vmexit */ else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) && - svm->vcpu.arch.apf.host_apf_reason != 0) + svm->vcpu.arch.exception.nested_apf != 0) vmexit = NESTED_EXIT_DONE; break; } diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c9c46e63f744..5a3bb1a697a2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2422,13 +2422,24 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) * KVM wants to inject page-faults which it got to the guest. This function * checks whether in a nested guest, we need to inject them to L1 or L2. */ -static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned nr) +static int nested_vmx_check_exception(struct kvm_vcpu *vcpu) { struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + unsigned int nr = vcpu->arch.exception.nr; - if (!(vmcs12->exception_bitmap & (1u << nr))) + if (!((vmcs12->exception_bitmap & (1u << nr)) || + (nr == PF_VECTOR && vcpu->arch.exception.nested_apf))) return 0; + if (vcpu->arch.exception.nested_apf) { + vmcs_write32(VM_EXIT_INTR_ERROR_CODE, vcpu->arch.exception.error_code); + nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI, + PF_VECTOR | INTR_TYPE_HARD_EXCEPTION | + INTR_INFO_DELIVER_CODE_MASK | INTR_INFO_VALID_MASK, + vcpu->arch.apf.nested_apf_token); + return 1; + } + nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI, vmcs_read32(VM_EXIT_INTR_INFO), vmcs_readl(EXIT_QUALIFICATION)); @@ -2445,7 +2456,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) u32 intr_info = nr | INTR_INFO_VALID_MASK; if (!reinject && is_guest_mode(vcpu) && - nested_vmx_check_exception(vcpu, nr)) + nested_vmx_check_exception(vcpu)) return; if (has_error_code) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e149c92476f1..f3f10154c133 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -450,7 +450,12 @@ EXPORT_SYMBOL_GPL(kvm_complete_insn_gp); void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) { ++vcpu->stat.pf_guest; - vcpu->arch.cr2 = fault->address; + vcpu->arch.exception.nested_apf = + is_guest_mode(vcpu) && fault->async_page_fault; + if (vcpu->arch.exception.nested_apf) + vcpu->arch.apf.nested_apf_token = fault->address; + else + vcpu->arch.cr2 = fault->address; kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code); } EXPORT_SYMBOL_GPL(kvm_inject_page_fault); @@ -8582,6 +8587,7 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, fault.error_code = 0; fault.nested_page_fault = false; fault.address = work->arch.token; + fault.async_page_fault = true; kvm_inject_page_fault(vcpu, &fault); } } @@ -8604,6 +8610,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, fault.error_code = 0; fault.nested_page_fault = false; fault.address = work->arch.token; + fault.async_page_fault = true; kvm_inject_page_fault(vcpu, &fault); } vcpu->arch.apf.halted = false; -- 2.20.1