Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 181 insertions, 32 deletions

diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 758e3b36d4c..01f572c10c7 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -49,31 +49,73 @@ static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
 			index = i;
 			break;
 		}
-	if (index < 0) {
+	if (index < 0)
 		printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
-		return 0;
-	}
 
 	return index;
 }
 
-static irqreturn_t kvm_assigned_dev_thread(int irq, void *dev_id)
+static irqreturn_t kvm_assigned_dev_intx(int irq, void *dev_id)
 {
 	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
+	int ret;
+
+	spin_lock(&assigned_dev->intx_lock);
+	if (pci_check_and_mask_intx(assigned_dev->dev)) {
+		assigned_dev->host_irq_disabled = true;
+		ret = IRQ_WAKE_THREAD;
+	} else
+		ret = IRQ_NONE;
+	spin_unlock(&assigned_dev->intx_lock);
+
+	return ret;
+}
 
-	if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_INTX) {
-		spin_lock(&assigned_dev->intx_lock);
+static void
+kvm_assigned_dev_raise_guest_irq(struct kvm_assigned_dev_kernel *assigned_dev,
+				 int vector)
+{
+	if (unlikely(assigned_dev->irq_requested_type &
+		     KVM_DEV_IRQ_GUEST_INTX)) {
+		spin_lock(&assigned_dev->intx_mask_lock);
+		if (!(assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX))
+			kvm_set_irq(assigned_dev->kvm,
+				    assigned_dev->irq_source_id, vector, 1);
+		spin_unlock(&assigned_dev->intx_mask_lock);
+	} else
+		kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
+			    vector, 1);
+}
+
+static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
+{
+	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
+
+	if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
+		spin_lock_irq(&assigned_dev->intx_lock);
 		disable_irq_nosync(irq);
 		assigned_dev->host_irq_disabled = true;
-		spin_unlock(&assigned_dev->intx_lock);
+		spin_unlock_irq(&assigned_dev->intx_lock);
 	}
 
-	kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
-		    assigned_dev->guest_irq, 1);
+	kvm_assigned_dev_raise_guest_irq(assigned_dev,
+					 assigned_dev->guest_irq);
 
 	return IRQ_HANDLED;
 }
 
+#ifdef __KVM_HAVE_MSI
+static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
+{
+	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
+
+	kvm_assigned_dev_raise_guest_irq(assigned_dev,
+					 assigned_dev->guest_irq);
+
+	return IRQ_HANDLED;
+}
+#endif
+
 #ifdef __KVM_HAVE_MSIX
 static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
 {
@@ -83,8 +125,7 @@ static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
 
 	if (index >= 0) {
 		vector = assigned_dev->guest_msix_entries[index].vector;
-		kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
-			    vector, 1);
+		kvm_assigned_dev_raise_guest_irq(assigned_dev, vector);
 	}
 
 	return IRQ_HANDLED;
@@ -100,15 +141,31 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
 
 	kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
 
-	/* The guest irq may be shared so this ack may be
-	 * from another device.
-	 */
-	spin_lock(&dev->intx_lock);
-	if (dev->host_irq_disabled) {
-		enable_irq(dev->host_irq);
-		dev->host_irq_disabled = false;
+	spin_lock(&dev->intx_mask_lock);
+
+	if (!(dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) {
+		bool reassert = false;
+
+		spin_lock_irq(&dev->intx_lock);
+		/*
+		 * The guest IRQ may be shared so this ack can come from an
+		 * IRQ for another guest device.
+		 */
+		if (dev->host_irq_disabled) {
+			if (!(dev->flags & KVM_DEV_ASSIGN_PCI_2_3))
+				enable_irq(dev->host_irq);
+			else if (!pci_check_and_unmask_intx(dev->dev))
+				reassert = true;
+			dev->host_irq_disabled = reassert;
+		}
+		spin_unlock_irq(&dev->intx_lock);
+
+		if (reassert)
+			kvm_set_irq(dev->kvm, dev->irq_source_id,
+				    dev->guest_irq, 1);
 	}
-	spin_unlock(&dev->intx_lock);
+
+	spin_unlock(&dev->intx_mask_lock);
 }
 
 static void deassign_guest_irq(struct kvm *kvm,
@@ -156,7 +213,15 @@ static void deassign_host_irq(struct kvm *kvm,
 		pci_disable_msix(assigned_dev->dev);
 	} else {
 		/* Deal with MSI and INTx */
-		disable_irq(assigned_dev->host_irq);
+		if ((assigned_dev->irq_requested_type &
+		     KVM_DEV_IRQ_HOST_INTX) &&
+		    (assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
+			spin_lock_irq(&assigned_dev->intx_lock);
+			pci_intx(assigned_dev->dev, false);
+			spin_unlock_irq(&assigned_dev->intx_lock);
+			synchronize_irq(assigned_dev->host_irq);
+		} else
+			disable_irq(assigned_dev->host_irq);
 
 		free_irq(assigned_dev->host_irq, assigned_dev);
 
@@ -237,15 +302,34 @@ void kvm_free_all_assigned_devices(struct kvm *kvm)
 static int assigned_device_enable_host_intx(struct kvm *kvm,
 					    struct kvm_assigned_dev_kernel *dev)
 {
+	irq_handler_t irq_handler;
+	unsigned long flags;
+
 	dev->host_irq = dev->dev->irq;
-	/* Even though this is PCI, we don't want to use shared
-	 * interrupts. Sharing host devices with guest-assigned devices
-	 * on the same interrupt line is not a happy situation: there
-	 * are going to be long delays in accepting, acking, etc.
+
+	/*
+	 * We can only share the IRQ line with other host devices if we are
+	 * able to disable the IRQ source at device-level - independently of
+	 * the guest driver. Otherwise host devices may suffer from unbounded
+	 * IRQ latencies when the guest keeps the line asserted.
 	 */
-	if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
-				 IRQF_ONESHOT, dev->irq_name, dev))
+	if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
+		irq_handler = kvm_assigned_dev_intx;
+		flags = IRQF_SHARED;
+	} else {
+		irq_handler = NULL;
+		flags = IRQF_ONESHOT;
+	}
+	if (request_threaded_irq(dev->host_irq, irq_handler,
+				 kvm_assigned_dev_thread_intx, flags,
+				 dev->irq_name, dev))
 		return -EIO;
+
+	if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
+		spin_lock_irq(&dev->intx_lock);
+		pci_intx(dev->dev, true);
+		spin_unlock_irq(&dev->intx_lock);
+	}
 	return 0;
 }
 
@@ -262,8 +346,9 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
 	}
 
 	dev->host_irq = dev->dev->irq;
-	if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
-				 0, dev->irq_name, dev)) {
+	if (request_threaded_irq(dev->host_irq, NULL,
+				 kvm_assigned_dev_thread_msi, 0,
+				 dev->irq_name, dev)) {
 		pci_disable_msi(dev->dev);
 		return -EIO;
 	}
@@ -321,7 +406,6 @@ static int assigned_device_enable_guest_msi(struct kvm *kvm,
 {
 	dev->guest_irq = irq->guest_irq;
 	dev->ack_notifier.gsi = -1;
-	dev->host_irq_disabled = false;
 	return 0;
 }
 #endif
@@ -333,7 +417,6 @@ static int assigned_device_enable_guest_msix(struct kvm *kvm,
 {
 	dev->guest_irq = irq->guest_irq;
 	dev->ack_notifier.gsi = -1;
-	dev->host_irq_disabled = false;
 	return 0;
 }
 #endif
@@ -367,6 +450,7 @@ static int assign_host_irq(struct kvm *kvm,
 	default:
 		r = -EINVAL;
 	}
+	dev->host_irq_disabled = false;
 
 	if (!r)
 		dev->irq_requested_type |= host_irq_type;
@@ -468,6 +552,7 @@ static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
 {
 	int r = -ENODEV;
 	struct kvm_assigned_dev_kernel *match;
+	unsigned long irq_type;
 
 	mutex_lock(&kvm->lock);
 
@@ -476,7 +561,9 @@ static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
 	if (!match)
 		goto out;
 
-	r = kvm_deassign_irq(kvm, match, assigned_irq->flags);
+	irq_type = assigned_irq->flags & (KVM_DEV_IRQ_HOST_MASK |
+					  KVM_DEV_IRQ_GUEST_MASK);
+	r = kvm_deassign_irq(kvm, match, irq_type);
 out:
 	mutex_unlock(&kvm->lock);
 	return r;
@@ -609,6 +696,10 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
 	if (!match->pci_saved_state)
 		printk(KERN_DEBUG "%s: Couldn't store %s saved state\n",
 		       __func__, dev_name(&dev->dev));
+
+	if (!pci_intx_mask_supported(dev))
+		assigned_dev->flags &= ~KVM_DEV_ASSIGN_PCI_2_3;
+
 	match->assigned_dev_id = assigned_dev->assigned_dev_id;
 	match->host_segnr = assigned_dev->segnr;
 	match->host_busnr = assigned_dev->busnr;
@@ -616,6 +707,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
 	match->flags = assigned_dev->flags;
 	match->dev = dev;
 	spin_lock_init(&match->intx_lock);
+	spin_lock_init(&match->intx_mask_lock);
 	match->irq_source_id = -1;
 	match->kvm = kvm;
 	match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
@@ -761,6 +853,55 @@ msix_entry_out:
 }
 #endif
 
+static int kvm_vm_ioctl_set_pci_irq_mask(struct kvm *kvm,
+		struct kvm_assigned_pci_dev *assigned_dev)
+{
+	int r = 0;
+	struct kvm_assigned_dev_kernel *match;
+
+	mutex_lock(&kvm->lock);
+
+	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+				      assigned_dev->assigned_dev_id);
+	if (!match) {
+		r = -ENODEV;
+		goto out;
+	}
+
+	spin_lock(&match->intx_mask_lock);
+
+	match->flags &= ~KVM_DEV_ASSIGN_MASK_INTX;
+	match->flags |= assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX;
+
+	if (match->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
+		if (assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX) {
+			kvm_set_irq(match->kvm, match->irq_source_id,
+				    match->guest_irq, 0);
+			/*
+			 * Masking at hardware-level is performed on demand,
+			 * i.e. when an IRQ actually arrives at the host.
+			 */
+		} else if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
+			/*
+			 * Unmask the IRQ line if required. Unmasking at
+			 * device level will be performed by user space.
+			 */
+			spin_lock_irq(&match->intx_lock);
+			if (match->host_irq_disabled) {
+				enable_irq(match->host_irq);
+				match->host_irq_disabled = false;
+			}
+			spin_unlock_irq(&match->intx_lock);
+		}
+	}
+
+	spin_unlock(&match->intx_mask_lock);
+
+out:
+	mutex_unlock(&kvm->lock);
+	return r;
+}
+
 long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
 				  unsigned long arg)
 {
@@ -868,6 +1009,15 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
 		break;
 	}
 #endif
+	case KVM_ASSIGN_SET_INTX_MASK: {
+		struct kvm_assigned_pci_dev assigned_dev;
+
+		r = -EFAULT;
+		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
+			goto out;
+		r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev);
+		break;
+	}
 	default:
 		r = -ENOTTY;
 		break;
@@ -875,4 +1025,3 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
 out:
 	return r;
 }
-