A late round of KVM/ARM fixes for v4.3-rc7, fixing:

- A bug where level-triggered interrupts lowered from userspace are still routed to the guest - A memory leak an a failed initialization path - A build error under certain configurations - Several timer bugs introduced with moving the timer to the active state handling instead of the masking trick. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEbBAABAgAGBQJWJmf7AAoJEEtpOizt6ddy35UH+NCAt1AInvQajAB1rzXzFSYh v9PQ5zJ7ZlP8M3HFYjerSl0HrGbi2Cwij5KYE+UAQkXIzCTTdDeB9TUSI/GYQ82M axel8Ob3deELp03nS5I+gP1NGX3HPDz445grScg7yl1lMs3uDy4viDDM8Vm8+HUX zZWGpDRHNW3b0myS5NVJvOP7Sm5t7DqklsNScZ04Nut7V8gYEUqEu+ZNKerIZkKn LrJUVYqqZf33bf6pWle95QZuNQtg84kion3qwWaNl+/8jFkAA8CODyvzar9VMHpf xA0xUkK1ERZ+hw2n0/BIgCxI4lXvROAx0YpZKnSMgEU5E5p5gGZYqlHCw8r1Rw== =VQSu -----END PGP SIGNATURE----- Merge tag 'kvm-arm-for-v4.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master A late round of KVM/ARM fixes for v4.3-rc7, fixing: - A bug where level-triggered interrupts lowered from userspace are still routed to the guest - A memory leak an a failed initialization path - A build error under certain configurations - Several timer bugs introduced with moving the timer to the active state handling instead of the masking trick.
2024-11-27 02:40:52 +07:00 · 2015-10-21 17:46:56 +02:00 · 2015-10-21 17:46:56 +02:00 · ad355e383d
commit ad355e383d
parent b10d92a54d 0d997491f8
4 changed files with 76 additions and 41 deletions
--- a/arch/arm/kvm/Kconfig
+++ b/arch/arm/kvm/Kconfig
@ -21,6 +21,7 @@ config KVM
 	depends on MMU && OF
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
+	select ARM_GIC
 	select HAVE_KVM_CPU_RELAX_INTERCEPT
 	select HAVE_KVM_ARCH_TLB_FLUSH_ALL
 	select KVM_MMIO
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@ -1080,7 +1080,7 @@ static int init_hyp_mode(void)
 	 */
 	err = kvm_timer_hyp_init();
 	if (err)
-		goto out_free_mappings;
+		goto out_free_context;

 #ifndef CONFIG_HOTPLUG_CPU
 	free_boot_hyp_pgd();
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@ -137,6 +137,8 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
 void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	bool phys_active;
+	int ret;

 	/*
 	 * We're about to run this vcpu again, so there is no need to
@ -151,6 +153,23 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 	 */
 	if (kvm_timer_should_fire(vcpu))
 		kvm_timer_inject_irq(vcpu);
+
+	/*
+	 * We keep track of whether the edge-triggered interrupt has been
+	 * signalled to the vgic/guest, and if so, we mask the interrupt and
+	 * the physical distributor to prevent the timer from raising a
+	 * physical interrupt whenever we run a guest, preventing forward
+	 * VCPU progress.
+	 */
+	if (kvm_vgic_get_phys_irq_active(timer->map))
+		phys_active = true;
+	else
+		phys_active = false;
+
+	ret = irq_set_irqchip_state(timer->map->irq,
+				    IRQCHIP_STATE_ACTIVE,
+				    phys_active);
+	WARN_ON(ret);
 }

 /**
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@ -531,6 +531,34 @@ bool vgic_handle_set_pending_reg(struct kvm *kvm,
 	return false;
 }

+/*
+ * If a mapped interrupt's state has been modified by the guest such that it
+ * is no longer active or pending, without it have gone through the sync path,
+ * then the map->active field must be cleared so the interrupt can be taken
+ * again.
+ */
+static void vgic_handle_clear_mapped_irq(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	struct list_head *root;
+	struct irq_phys_map_entry *entry;
+	struct irq_phys_map *map;
+
+	rcu_read_lock();
+
+	/* Check for PPIs */
+	root = &vgic_cpu->irq_phys_map_list;
+	list_for_each_entry_rcu(entry, root, entry) {
+		map = &entry->map;
+
+		if (!vgic_dist_irq_is_pending(vcpu, map->virt_irq) &&
+		    !vgic_irq_is_active(vcpu, map->virt_irq))
+			map->active = false;
+	}
+
+	rcu_read_unlock();
+}
+
 bool vgic_handle_clear_pending_reg(struct kvm *kvm,
 				   struct kvm_exit_mmio *mmio,
 				   phys_addr_t offset, int vcpu_id)
@ -561,6 +589,7 @@ bool vgic_handle_clear_pending_reg(struct kvm *kvm,
 					  vcpu_id, offset);
 		vgic_reg_access(mmio, reg, offset, mode);

+		vgic_handle_clear_mapped_irq(kvm_get_vcpu(kvm, vcpu_id));
 		vgic_update_state(kvm);
 		return true;
 	}
@ -598,6 +627,7 @@ bool vgic_handle_clear_active_reg(struct kvm *kvm,
 			ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);

 	if (mmio->is_write) {
+		vgic_handle_clear_mapped_irq(kvm_get_vcpu(kvm, vcpu_id));
 		vgic_update_state(kvm);
 		return true;
 	}
@ -982,6 +1012,12 @@ static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
 	pend_percpu = vcpu->arch.vgic_cpu.pending_percpu;
 	pend_shared = vcpu->arch.vgic_cpu.pending_shared;

+	if (!dist->enabled) {
+		bitmap_zero(pend_percpu, VGIC_NR_PRIVATE_IRQS);
+		bitmap_zero(pend_shared, nr_shared);
+		return 0;
+	}
+
 	pending = vgic_bitmap_get_cpu_map(&dist->irq_pending, vcpu_id);
 	enabled = vgic_bitmap_get_cpu_map(&dist->irq_enabled, vcpu_id);
 	bitmap_and(pend_percpu, pending, enabled, VGIC_NR_PRIVATE_IRQS);
@ -1009,11 +1045,6 @@ void vgic_update_state(struct kvm *kvm)
 	struct kvm_vcpu *vcpu;
 	int c;

-	if (!dist->enabled) {
-		set_bit(0, dist->irq_pending_on_cpu);
-		return;
-	}
-
 	kvm_for_each_vcpu(c, vcpu, kvm) {
 		if (compute_pending_for_cpu(vcpu))
 			set_bit(c, dist->irq_pending_on_cpu);
@ -1092,6 +1123,15 @@ static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu)
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_lr vlr = vgic_get_lr(vcpu, lr_nr);

+	/*
+	 * We must transfer the pending state back to the distributor before
+	 * retiring the LR, otherwise we may loose edge-triggered interrupts.
+	 */
+	if (vlr.state & LR_STATE_PENDING) {
+		vgic_dist_irq_set_pending(vcpu, irq);
+		vlr.hwirq = 0;
+	}
+
 	vlr.state = 0;
 	vgic_set_lr(vcpu, lr_nr, vlr);
 	clear_bit(lr_nr, vgic_cpu->lr_used);
@ -1132,7 +1172,8 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu *vcpu, int irq,
 		kvm_debug("Set active, clear distributor: 0x%x\n", vlr.state);
 		vgic_irq_clear_active(vcpu, irq);
 		vgic_update_state(vcpu->kvm);
-	} else if (vgic_dist_irq_is_pending(vcpu, irq)) {
+	} else {
+		WARN_ON(!vgic_dist_irq_is_pending(vcpu, irq));
 		vlr.state |= LR_STATE_PENDING;
 		kvm_debug("Set pending: 0x%x\n", vlr.state);
 	}
@ -1240,7 +1281,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 	unsigned long *pa_percpu, *pa_shared;
-	int i, vcpu_id, lr, ret;
+	int i, vcpu_id;
 	int overflow = 0;
 	int nr_shared = vgic_nr_shared_irqs(dist);

@ -1295,31 +1336,6 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 		 */
 		clear_bit(vcpu_id, dist->irq_pending_on_cpu);
 	}
-
-	for (lr = 0; lr < vgic->nr_lr; lr++) {
-		struct vgic_lr vlr;
-
-		if (!test_bit(lr, vgic_cpu->lr_used))
-			continue;
-
-		vlr = vgic_get_lr(vcpu, lr);
-
-		/*
-		 * If we have a mapping, and the virtual interrupt is
-		 * presented to the guest (as pending or active), then we must
-		 * set the state to active in the physical world. See
-		 * Documentation/virtual/kvm/arm/vgic-mapped-irqs.txt.
-		 */
-		if (vlr.state & LR_HW) {
-			struct irq_phys_map *map;
-			map = vgic_irq_map_search(vcpu, vlr.irq);
-
-			ret = irq_set_irqchip_state(map->irq,
-						    IRQCHIP_STATE_ACTIVE,
-						    true);
-			WARN_ON(ret);
-		}
-	}
 }

 static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
@ -1421,7 +1437,7 @@ static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
 		return 0;

 	map = vgic_irq_map_search(vcpu, vlr.irq);
-	BUG_ON(!map || !map->active);
+	BUG_ON(!map);

 	ret = irq_get_irqchip_state(map->irq,
 				    IRQCHIP_STATE_ACTIVE,
@ -1429,13 +1445,8 @@ static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)

 	WARN_ON(ret);

-	if (map->active) {
-		ret = irq_set_irqchip_state(map->irq,
-					    IRQCHIP_STATE_ACTIVE,
-					    false);
-		WARN_ON(ret);
+	if (map->active)
 		return 0;
-	}

 	return 1;
 }
@ -1607,8 +1618,12 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 	} else {
 		if (level_triggered) {
 			vgic_dist_irq_clear_level(vcpu, irq_num);
-			if (!vgic_dist_irq_soft_pend(vcpu, irq_num))
+			if (!vgic_dist_irq_soft_pend(vcpu, irq_num)) {
 				vgic_dist_irq_clear_pending(vcpu, irq_num);
+				vgic_cpu_irq_clear(vcpu, irq_num);
+				if (!compute_pending_for_cpu(vcpu))
+					clear_bit(cpuid, dist->irq_pending_on_cpu);
+			}
 		}

 		ret = false;