2 files changed, 13 insertions, 1 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 161816284192..aacc5449f586 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -345,6 +345,7 @@ struct kvm_assigned_dev_kernel {
         int flags;
         struct pci_dev *dev;
         struct kvm *kvm;
+        spinlock_t assigned_dev_lock;
 };
 
 struct kvm_irq_mask_notifier {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 29c0afb064da..687d113a3e5e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -42,6 +42,7 @@
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/bitops.h>
+#include <linux/spinlock.h>
 
 #include <asm/processor.h>
 #include <asm/io.h>
@@ -130,6 +131,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
          * finer-grained lock, update this
          */
         mutex_lock(&kvm->lock);
+        spin_lock_irq(&assigned_dev->assigned_dev_lock);
         if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                 struct kvm_guest_msix_entry *guest_entries =
                         assigned_dev->guest_msix_entries;
@@ -156,18 +158,21 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
                 }
         }
 
+        spin_unlock_irq(&assigned_dev->assigned_dev_lock);
         mutex_unlock(&assigned_dev->kvm->lock);
 }
 
 static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
 {
+        unsigned long flags;
         struct kvm_assigned_dev_kernel *assigned_dev =
                 (struct kvm_assigned_dev_kernel *) dev_id;
 
+        spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags);
         if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                 int index = find_index_from_host_irq(assigned_dev, irq);
                 if (index < 0)
-                        return IRQ_HANDLED;
+                        goto out;
                 assigned_dev->guest_msix_entries[index].flags |=
                         KVM_ASSIGNED_MSIX_PENDING;
         }
@@ -177,6 +182,8 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
         disable_irq_nosync(irq);
         assigned_dev->host_irq_disabled = true;
 
+out:
+        spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags);
         return IRQ_HANDLED;
 }
 
@@ -184,6 +191,7 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
 static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
 {
         struct kvm_assigned_dev_kernel *dev;
+        unsigned long flags;
 
         if (kian->gsi == -1)
                 return;
@@ -196,10 +204,12 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
         /* The guest irq may be shared so this ack may be
          * from another device.
          */
+        spin_lock_irqsave(&dev->assigned_dev_lock, flags);
         if (dev->host_irq_disabled) {
                 enable_irq(dev->host_irq);
                 dev->host_irq_disabled = false;
         }
+        spin_unlock_irqrestore(&dev->assigned_dev_lock, flags);
 }
 
 static void deassign_guest_irq(struct kvm *kvm,
@@ -615,6 +625,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
         match->host_devfn = assigned_dev->devfn;
         match->flags = assigned_dev->flags;
         match->dev = dev;
+        spin_lock_init(&match->assigned_dev_lock);
         match->irq_source_id = -1;
         match->kvm = kvm;
         match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;