From 35754c987f252e859bfa390a6816e85563afe79d Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 29 Jul 2015 12:05:37 +0200 Subject: [PATCH] KVM: x86: introduce lapic_in_kernel Avoid pointer chasing and memory barriers, and simplify the code when split irqchip (LAPIC in kernel, IOAPIC/PIC in userspace) is introduced. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/irq.c | 6 +++--- arch/x86/kvm/irq.h | 8 ++++++++ arch/x86/kvm/lapic.c | 4 ++-- arch/x86/kvm/mmu.c | 2 +- arch/x86/kvm/svm.c | 4 ++-- arch/x86/kvm/vmx.c | 46 +++++++++++++++++++------------------------- arch/x86/kvm/x86.c | 18 ++++++++--------- 7 files changed, 45 insertions(+), 43 deletions(-) diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index c0dad893dc59..b653ae202c8e 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -57,7 +57,7 @@ static int kvm_cpu_has_extint(struct kvm_vcpu *v) */ int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) { - if (!irqchip_in_kernel(v->kvm)) + if (!lapic_in_kernel(v)) return v->arch.interrupt.pending; if (kvm_cpu_has_extint(v)) @@ -75,7 +75,7 @@ int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) */ int kvm_cpu_has_interrupt(struct kvm_vcpu *v) { - if (!irqchip_in_kernel(v->kvm)) + if (!lapic_in_kernel(v)) return v->arch.interrupt.pending; if (kvm_cpu_has_extint(v)) @@ -103,7 +103,7 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v) { int vector; - if (!irqchip_in_kernel(v->kvm)) + if (!lapic_in_kernel(v)) return v->arch.interrupt.nr; vector = kvm_cpu_get_extint(v); diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index 3d782a2c336a..9e6e7e04de98 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -92,6 +92,14 @@ static inline int irqchip_in_kernel(struct kvm *kvm) return vpic != NULL; } +static inline int lapic_in_kernel(struct kvm_vcpu *vcpu) +{ + /* Same as irqchip_in_kernel(vcpu->kvm), but with less + * pointer chasing and no unnecessary memory barriers. + */ + return vcpu->arch.apic != NULL; +} + void kvm_pic_reset(struct kvm_kpic_state *s); void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c568d69c7060..c4bcc86d6dc4 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1985,7 +1985,7 @@ int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data) struct kvm_lapic *apic = vcpu->arch.apic; u32 reg = (msr - APIC_BASE_MSR) << 4; - if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic)) + if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) return 1; if (reg == APIC_ICR2) @@ -2002,7 +2002,7 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data) struct kvm_lapic *apic = vcpu->arch.apic; u32 reg = (msr - APIC_BASE_MSR) << 4, low, high = 0; - if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic)) + if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) return 1; if (reg == APIC_DFR || reg == APIC_ICR2) { diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ff606f507913..c3f39aa9b9cb 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3427,7 +3427,7 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn) static bool can_do_async_pf(struct kvm_vcpu *vcpu) { - if (unlikely(!irqchip_in_kernel(vcpu->kvm) || + if (unlikely(!lapic_in_kernel(vcpu) || kvm_event_needs_reinjection(vcpu))) return false; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 9a37e487aca0..34c089023827 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3060,7 +3060,7 @@ static int cr8_write_interception(struct vcpu_svm *svm) u8 cr8_prev = kvm_get_cr8(&svm->vcpu); /* instruction emulation calls kvm_set_cr8() */ r = cr_interception(svm); - if (irqchip_in_kernel(svm->vcpu.kvm)) + if (lapic_in_kernel(&svm->vcpu)) return r; if (cr8_prev <= kvm_get_cr8(&svm->vcpu)) return r; @@ -3305,7 +3305,7 @@ static int interrupt_window_interception(struct vcpu_svm *svm) * If the user space waits to inject interrupts, exit as soon as * possible */ - if (!irqchip_in_kernel(svm->vcpu.kvm) && + if (!lapic_in_kernel(&svm->vcpu) && kvm_run->request_interrupt_window && !kvm_cpu_has_interrupt(&svm->vcpu)) { kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index b8a90c4f676f..4729b7f6e5f2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -809,7 +809,6 @@ static void kvm_cpu_vmxon(u64 addr); static void kvm_cpu_vmxoff(void); static bool vmx_mpx_supported(void); static bool vmx_xsaves_supported(void); -static int vmx_vm_has_apicv(struct kvm *kvm); static int vmx_cpu_uses_apicv(struct kvm_vcpu *vcpu); static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr); static void vmx_set_segment(struct kvm_vcpu *vcpu, @@ -947,9 +946,9 @@ static inline bool cpu_has_vmx_tpr_shadow(void) return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW; } -static inline bool vm_need_tpr_shadow(struct kvm *kvm) +static inline bool cpu_need_tpr_shadow(struct kvm_vcpu *vcpu) { - return (cpu_has_vmx_tpr_shadow()) && (irqchip_in_kernel(kvm)); + return cpu_has_vmx_tpr_shadow() && lapic_in_kernel(vcpu); } static inline bool cpu_has_secondary_exec_ctrls(void) @@ -1063,9 +1062,9 @@ static inline bool cpu_has_vmx_ple(void) SECONDARY_EXEC_PAUSE_LOOP_EXITING; } -static inline bool vm_need_virtualize_apic_accesses(struct kvm *kvm) +static inline bool cpu_need_virtualize_apic_accesses(struct kvm_vcpu *vcpu) { - return flexpriority_enabled && irqchip_in_kernel(kvm); + return flexpriority_enabled && lapic_in_kernel(vcpu); } static inline bool cpu_has_vmx_vpid(void) @@ -2378,7 +2377,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) vmx->nested.nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR | PIN_BASED_VMX_PREEMPTION_TIMER; - if (vmx_vm_has_apicv(vmx->vcpu.kvm)) + if (vmx_cpu_uses_apicv(&vmx->vcpu)) vmx->nested.nested_vmx_pinbased_ctls_high |= PIN_BASED_POSTED_INTR; @@ -4333,14 +4332,9 @@ static void vmx_disable_intercept_msr_write_x2apic(u32 msr) msr, MSR_TYPE_W); } -static int vmx_vm_has_apicv(struct kvm *kvm) -{ - return enable_apicv && irqchip_in_kernel(kvm); -} - static int vmx_cpu_uses_apicv(struct kvm_vcpu *vcpu) { - return vmx_vm_has_apicv(vcpu->kvm); + return enable_apicv && lapic_in_kernel(vcpu); } static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) @@ -4520,7 +4514,7 @@ static u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx) { u32 pin_based_exec_ctrl = vmcs_config.pin_based_exec_ctrl; - if (!vmx_vm_has_apicv(vmx->vcpu.kvm)) + if (!vmx_cpu_uses_apicv(&vmx->vcpu)) pin_based_exec_ctrl &= ~PIN_BASED_POSTED_INTR; return pin_based_exec_ctrl; } @@ -4532,7 +4526,7 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx) if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT) exec_control &= ~CPU_BASED_MOV_DR_EXITING; - if (!vm_need_tpr_shadow(vmx->vcpu.kvm)) { + if (!cpu_need_tpr_shadow(&vmx->vcpu)) { exec_control &= ~CPU_BASED_TPR_SHADOW; #ifdef CONFIG_X86_64 exec_control |= CPU_BASED_CR8_STORE_EXITING | @@ -4549,7 +4543,7 @@ static u32 vmx_exec_control(struct vcpu_vmx *vmx) static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) { u32 exec_control = vmcs_config.cpu_based_2nd_exec_ctrl; - if (!vm_need_virtualize_apic_accesses(vmx->vcpu.kvm)) + if (!cpu_need_virtualize_apic_accesses(&vmx->vcpu)) exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; if (vmx->vpid == 0) exec_control &= ~SECONDARY_EXEC_ENABLE_VPID; @@ -4563,7 +4557,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST; if (!ple_gap) exec_control &= ~SECONDARY_EXEC_PAUSE_LOOP_EXITING; - if (!vmx_vm_has_apicv(vmx->vcpu.kvm)) + if (!vmx_cpu_uses_apicv(&vmx->vcpu)) exec_control &= ~(SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY); exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE; @@ -4624,7 +4618,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) vmx_secondary_exec_control(vmx)); } - if (vmx_vm_has_apicv(vmx->vcpu.kvm)) { + if (vmx_cpu_uses_apicv(&vmx->vcpu)) { vmcs_write64(EOI_EXIT_BITMAP0, 0); vmcs_write64(EOI_EXIT_BITMAP1, 0); vmcs_write64(EOI_EXIT_BITMAP2, 0); @@ -4768,7 +4762,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) if (cpu_has_vmx_tpr_shadow() && !init_event) { vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0); - if (vm_need_tpr_shadow(vcpu->kvm)) + if (cpu_need_tpr_shadow(vcpu)) vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, __pa(vcpu->arch.apic->regs)); vmcs_write32(TPR_THRESHOLD, 0); @@ -4776,7 +4770,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); - if (vmx_vm_has_apicv(vcpu->kvm)) + if (vmx_cpu_uses_apicv(vcpu)) memset(&vmx->pi_desc, 0, sizeof(struct pi_desc)); if (vmx->vpid != 0) @@ -5316,7 +5310,7 @@ static int handle_cr(struct kvm_vcpu *vcpu) u8 cr8 = (u8)val; err = kvm_set_cr8(vcpu, cr8); kvm_complete_insn_gp(vcpu, err); - if (irqchip_in_kernel(vcpu->kvm)) + if (lapic_in_kernel(vcpu)) return 1; if (cr8_prev <= cr8) return 1; @@ -5535,7 +5529,7 @@ static int handle_interrupt_window(struct kvm_vcpu *vcpu) * If the user space waits to inject interrupts, exit as soon as * possible */ - if (!irqchip_in_kernel(vcpu->kvm) && + if (!lapic_in_kernel(vcpu) && vcpu->run->request_interrupt_window && !kvm_cpu_has_interrupt(vcpu)) { vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN; @@ -7944,10 +7938,10 @@ static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set) * apicv */ if (!cpu_has_vmx_virtualize_x2apic_mode() || - !vmx_vm_has_apicv(vcpu->kvm)) + !vmx_cpu_uses_apicv(vcpu)) return; - if (!vm_need_tpr_shadow(vcpu->kvm)) + if (!cpu_need_tpr_shadow(vcpu)) return; sec_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); @@ -8052,7 +8046,7 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr) static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu) { u64 *eoi_exit_bitmap = vcpu->arch.eoi_exit_bitmap; - if (!vmx_vm_has_apicv(vcpu->kvm)) + if (!vmx_cpu_uses_apicv(vcpu)) return; vmcs_write64(EOI_EXIT_BITMAP0, eoi_exit_bitmap[0]); @@ -8551,7 +8545,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) put_cpu(); if (err) goto free_vmcs; - if (vm_need_virtualize_apic_accesses(kvm)) { + if (cpu_need_virtualize_apic_accesses(&vmx->vcpu)) { err = alloc_apic_access_page(kvm); if (err) goto free_vmcs; @@ -9344,7 +9338,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs_write64(APIC_ACCESS_ADDR, page_to_phys(vmx->nested.apic_access_page)); } else if (!(nested_cpu_has_virt_x2apic_mode(vmcs12)) && - (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))) { + cpu_need_virtualize_apic_accesses(&vmx->vcpu)) { exec_control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; kvm_vcpu_reload_apic_access_page(vcpu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c4adb8847b23..88fb3bf2ae6d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -788,7 +788,7 @@ int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8) { if (cr8 & CR8_RESERVED_BITS) return 1; - if (irqchip_in_kernel(vcpu->kvm)) + if (lapic_in_kernel(vcpu)) kvm_lapic_set_tpr(vcpu, cr8); else vcpu->arch.cr8 = cr8; @@ -798,7 +798,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr8); unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu) { - if (irqchip_in_kernel(vcpu->kvm)) + if (lapic_in_kernel(vcpu)) return kvm_lapic_get_cr8(vcpu); else return vcpu->arch.cr8; @@ -3175,7 +3175,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, struct kvm_vapic_addr va; r = -EINVAL; - if (!irqchip_in_kernel(vcpu->kvm)) + if (!lapic_in_kernel(vcpu)) goto out; r = -EFAULT; if (copy_from_user(&va, argp, sizeof va)) @@ -5666,7 +5666,7 @@ void kvm_arch_exit(void) int kvm_vcpu_halt(struct kvm_vcpu *vcpu) { ++vcpu->stat.halt_exits; - if (irqchip_in_kernel(vcpu->kvm)) { + if (lapic_in_kernel(vcpu)) { vcpu->arch.mp_state = KVM_MP_STATE_HALTED; return 1; } else { @@ -6162,7 +6162,7 @@ void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) { struct page *page = NULL; - if (!irqchip_in_kernel(vcpu->kvm)) + if (!lapic_in_kernel(vcpu)) return; if (!kvm_x86_ops->set_apic_access_page_addr) @@ -6200,7 +6200,7 @@ void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm, static int vcpu_enter_guest(struct kvm_vcpu *vcpu) { int r; - bool req_int_win = !irqchip_in_kernel(vcpu->kvm) && + bool req_int_win = !lapic_in_kernel(vcpu) && vcpu->run->request_interrupt_window; bool req_immediate_exit = false; @@ -6597,7 +6597,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) } /* re-sync apic's tpr */ - if (!irqchip_in_kernel(vcpu->kvm)) { + if (!lapic_in_kernel(vcpu)) { if (kvm_set_cr8(vcpu, kvm_run->cr8) != 0) { r = -EINVAL; goto out; @@ -7297,7 +7297,7 @@ bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu) bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { - return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL); + return irqchip_in_kernel(vcpu->kvm) == lapic_in_kernel(vcpu); } struct static_key kvm_no_apic_vcpu __read_mostly; @@ -7391,7 +7391,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) kvm_mmu_destroy(vcpu); srcu_read_unlock(&vcpu->kvm->srcu, idx); free_page((unsigned long)vcpu->arch.pio_data); - if (!irqchip_in_kernel(vcpu->kvm)) + if (!lapic_in_kernel(vcpu)) static_key_slow_dec(&kvm_no_apic_vcpu); } -- 2.20.1