From 68fd66f100d196d35ab3008d4c69af3a0d7e7200 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Mon, 25 May 2020 16:41:17 +0200 Subject: KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Currently, APF mechanism relies on the #PF abuse where the token is being passed through CR2. If we switch to using interrupts to deliver page-ready notifications we need a different way to pass the data. Extent the existing 'struct kvm_vcpu_pv_apf_data' with token information for page-ready notifications. While on it, rename 'reason' to 'flags'. This doesn't change the semantics as we only have reasons '1' and '2' and these can be treated as bit flags but KVM_PV_REASON_PAGE_READY is going away with interrupt based delivery making 'reason' name misleading. The newly introduced apf_put_user_ready() temporary puts both flags and token information, this will be changed to put token only when we switch to interrupt based notifications. Signed-off-by: Vitaly Kuznetsov Message-Id: <20200525144125.143875-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 6 +++--- arch/x86/kvm/svm/nested.c | 2 +- arch/x86/kvm/svm/svm.c | 3 ++- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/vmx.c | 4 ++-- arch/x86/kvm/x86.c | 17 +++++++++++++---- 6 files changed, 22 insertions(+), 12 deletions(-) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 2e62a03410c7..5de1929cfc55 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4164,7 +4164,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, #endif vcpu->arch.l1tf_flush_l1d = true; - switch (vcpu->arch.apf.host_apf_reason) { + switch (vcpu->arch.apf.host_apf_flags) { default: trace_kvm_page_fault(fault_address, error_code); @@ -4174,13 +4174,13 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, insn_len); break; case KVM_PV_REASON_PAGE_NOT_PRESENT: - vcpu->arch.apf.host_apf_reason = 0; + vcpu->arch.apf.host_apf_flags = 0; local_irq_disable(); kvm_async_pf_task_wait_schedule(fault_address); local_irq_enable(); break; case KVM_PV_REASON_PAGE_READY: - vcpu->arch.apf.host_apf_reason = 0; + vcpu->arch.apf.host_apf_flags = 0; local_irq_disable(); kvm_async_pf_task_wake(fault_address); local_irq_enable(); diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 6b1049148c1b..8a6db11dcb43 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -921,7 +921,7 @@ int nested_svm_exit_special(struct vcpu_svm *svm) if (get_host_vmcb(svm)->control.intercept_exceptions & excp_bits) return NESTED_EXIT_HOST; else if (exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR && - svm->vcpu.arch.apf.host_apf_reason) + svm->vcpu.arch.apf.host_apf_flags) /* Trap async PF even if not shadowing */ return NESTED_EXIT_HOST; break; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 3871bfb40594..9e333b91ff78 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3459,7 +3459,8 @@ static fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) /* if exit due to PF check for async PF */ if (svm->vmcb->control.exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) - svm->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason(); + svm->vcpu.arch.apf.host_apf_flags = + kvm_read_and_reset_apf_flags(); if (npt_enabled) { vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR); diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 106fc6fceb97..119a2f7395d6 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5652,7 +5652,7 @@ static bool nested_vmx_l0_wants_exit(struct kvm_vcpu *vcpu, u32 exit_reason) if (is_nmi(intr_info)) return true; else if (is_page_fault(intr_info)) - return vcpu->arch.apf.host_apf_reason || !enable_ept; + return vcpu->arch.apf.host_apf_flags || !enable_ept; else if (is_debug(intr_info) && vcpu->guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 7b55dc6230a9..5a43af0061ef 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4765,7 +4765,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) if (is_page_fault(intr_info)) { cr2 = vmx_get_exit_qual(vcpu); /* EPT won't cause page fault directly */ - WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && enable_ept); + WARN_ON_ONCE(!vcpu->arch.apf.host_apf_flags && enable_ept); return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0); } @@ -6360,7 +6360,7 @@ static void handle_exception_nmi_irqoff(struct vcpu_vmx *vmx) /* if exit due to PF check for async PF */ if (is_page_fault(intr_info)) { - vmx->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason(); + vmx->vcpu.arch.apf.host_apf_flags = kvm_read_and_reset_apf_flags(); /* Handle machine checks before interrupts are enabled */ } else if (is_machine_check(intr_info)) { kvm_machine_check(); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b9a5ff7b922c..84aa3c1519ed 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2690,7 +2690,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) } if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa, - sizeof(u32))) + sizeof(u64))) return 1; vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS); @@ -10420,8 +10420,17 @@ static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) } } -static int apf_put_user(struct kvm_vcpu *vcpu, u32 val) +static inline int apf_put_user_notpresent(struct kvm_vcpu *vcpu) { + u32 reason = KVM_PV_REASON_PAGE_NOT_PRESENT; + + return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &reason, + sizeof(reason)); +} + +static inline int apf_put_user_ready(struct kvm_vcpu *vcpu, u32 token) +{ + u64 val = (u64)token << 32 | KVM_PV_REASON_PAGE_READY; return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &val, sizeof(val)); @@ -10466,7 +10475,7 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, kvm_add_async_pf_gfn(vcpu, work->arch.gfn); if (kvm_can_deliver_async_pf(vcpu) && - !apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) { + !apf_put_user_notpresent(vcpu)) { fault.vector = PF_VECTOR; fault.error_code_valid = true; fault.error_code = 0; @@ -10499,7 +10508,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, trace_kvm_async_pf_ready(work->arch.token, work->cr2_or_gpa); if (vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED && - !apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) { + !apf_put_user_ready(vcpu, work->arch.token)) { fault.vector = PF_VECTOR; fault.error_code_valid = true; fault.error_code = 0; -- cgit v1.2.3