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 <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index c0dad89..b653ae2 100644 (file)
--- 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 3d782a2..9e6e7e0 100644 (file)
--- 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 c568d69..c4bcc86 100644 (file)
--- 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 ff606f5..c3f39aa 100644 (file)
--- 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 9a37e48..34c0890 100644 (file)
--- 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 b8a90c4..4729b7f 100644 (file)
--- 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 c4adb88..88fb3bf 100644 (file)
--- 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);
 }