1 files changed, 41 insertions, 33 deletions

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 5ae620d32fac..04d69cd7049b 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -14,32 +14,28 @@
 
 #include "coalesced_mmio.h"
 
-static int coalesced_mmio_in_range(struct kvm_io_device *this,
-                                   gpa_t addr, int len, int is_write)
+static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
+{
+        return container_of(dev, struct kvm_coalesced_mmio_dev, dev);
+}
+
+static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
+                                   gpa_t addr, int len)
 {
-        struct kvm_coalesced_mmio_dev *dev =
-                                (struct kvm_coalesced_mmio_dev*)this->private;
         struct kvm_coalesced_mmio_zone *zone;
-        int next;
+        struct kvm_coalesced_mmio_ring *ring;
+        unsigned avail;
         int i;
 
-        if (!is_write)
-                return 0;
-
-        /* kvm->lock is taken by the caller and must be not released before
-         * dev.read/write
-         */
-
         /* Are we able to batch it ? */
 
         /* last is the first free entry
          * check if we don't meet the first used entry
          * there is always one unused entry in the buffer
          */
-
-        next = (dev->kvm->coalesced_mmio_ring->last + 1) %
-                                                        KVM_COALESCED_MMIO_MAX;
-        if (next == dev->kvm->coalesced_mmio_ring->first) {
+        ring = dev->kvm->coalesced_mmio_ring;
+        avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
+        if (avail < KVM_MAX_VCPUS) {
                 /* full */
                 return 0;
         }
@@ -60,14 +56,15 @@ static int coalesced_mmio_in_range(struct kvm_io_device *this,
         return 0;
 }
 
-static void coalesced_mmio_write(struct kvm_io_device *this,
-                                 gpa_t addr, int len, const void *val)
+static int coalesced_mmio_write(struct kvm_io_device *this,
+                                gpa_t addr, int len, const void *val)
 {
-        struct kvm_coalesced_mmio_dev *dev =
-                                (struct kvm_coalesced_mmio_dev*)this->private;
+        struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
         struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
+        if (!coalesced_mmio_in_range(dev, addr, len))
+                return -EOPNOTSUPP;
 
-        /* kvm->lock must be taken by caller before call to in_range()*/
+        spin_lock(&dev->lock);
 
         /* copy data in first free entry of the ring */
 
@@ -76,29 +73,40 @@ static void coalesced_mmio_write(struct kvm_io_device *this,
         memcpy(ring->coalesced_mmio[ring->last].data, val, len);
         smp_wmb();
         ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
+        spin_unlock(&dev->lock);
+        return 0;
 }
 
 static void coalesced_mmio_destructor(struct kvm_io_device *this)
 {
-        kfree(this);
+        struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
+
+        kfree(dev);
 }
 
+static const struct kvm_io_device_ops coalesced_mmio_ops = {
+        .write      = coalesced_mmio_write,
+        .destructor = coalesced_mmio_destructor,
+};
+
 int kvm_coalesced_mmio_init(struct kvm *kvm)
 {
         struct kvm_coalesced_mmio_dev *dev;
+        int ret;
 
         dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
         if (!dev)
                 return -ENOMEM;
-        dev->dev.write  = coalesced_mmio_write;
-        dev->dev.in_range  = coalesced_mmio_in_range;
-        dev->dev.destructor  = coalesced_mmio_destructor;
-        dev->dev.private  = dev;
+        spin_lock_init(&dev->lock);
+        kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
         dev->kvm = kvm;
         kvm->coalesced_mmio_dev = dev;
-        kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev);
 
-        return 0;
+        ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
+        if (ret < 0)
+                kfree(dev);
+
+        return ret;
 }
 
 int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
@@ -109,16 +117,16 @@ int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
         if (dev == NULL)
                 return -EINVAL;
 
-        mutex_lock(&kvm->lock);
+        down_write(&kvm->slots_lock);
         if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
-                mutex_unlock(&kvm->lock);
+                up_write(&kvm->slots_lock);
                 return -ENOBUFS;
         }
 
         dev->zone[dev->nb_zones] = *zone;
         dev->nb_zones++;
 
-        mutex_unlock(&kvm->lock);
+        up_write(&kvm->slots_lock);
         return 0;
 }
 
@@ -132,7 +140,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
         if (dev == NULL)
                 return -EINVAL;
 
-        mutex_lock(&kvm->lock);
+        down_write(&kvm->slots_lock);
 
         i = dev->nb_zones;
         while(i) {
@@ -150,7 +158,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
                 i--;
         }
 
-        mutex_unlock(&kvm->lock);
+        up_write(&kvm->slots_lock);
 
         return 0;
 }