Merge branch 'msm-fix' of git://codeaurora.org/quic/kernel/davidb/linux-msm into...

[pandora-kernel.git] / virt / kvm / coalesced_mmio.c

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index fc84875..a6ec206 100644 (file)
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -24,10 +24,19 @@ static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
 static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
                                   gpa_t addr, int len)
 {
-       struct kvm_coalesced_mmio_zone *zone;
+       /* is it in a batchable area ?
+        * (addr,len) is fully included in
+        * (zone->addr, zone->size)
+        */
+
+       return (dev->zone.addr <= addr &&
+               addr + len <= dev->zone.addr + dev->zone.size);
+}
+
+static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
+{
        struct kvm_coalesced_mmio_ring *ring;
        unsigned avail;
-       int i;
 
        /* Are we able to batch it ? */
 
@@ -37,25 +46,12 @@ static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
         */
        ring = dev->kvm->coalesced_mmio_ring;
        avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
-       if (avail < KVM_MAX_VCPUS) {
+       if (avail == 0) {
                /* full */
                return 0;
        }
 
-       /* is it in a batchable area ? */
-
-       for (i = 0; i < dev->nb_zones; i++) {
-               zone = &dev->zone[i];
-
-               /* (addr,len) is fully included in
-                * (zone->addr, zone->size)
-                */
-
-               if (zone->addr <= addr &&
-                   addr + len <= zone->addr + zone->size)
-                       return 1;
-       }
-       return 0;
+       return 1;
 }
 
 static int coalesced_mmio_write(struct kvm_io_device *this,
@@ -63,10 +59,16 @@ static int coalesced_mmio_write(struct kvm_io_device *this,
 {
        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;
 
-       spin_lock(&dev->lock);
+       spin_lock(&dev->kvm->ring_lock);
+
+       if (!coalesced_mmio_has_room(dev)) {
+               spin_unlock(&dev->kvm->ring_lock);
+               return -EOPNOTSUPP;
+       }
 
        /* copy data in first free entry of the ring */
 
@@ -75,7 +77,7 @@ static int 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);
+       spin_unlock(&dev->kvm->ring_lock);
        return 0;
 }
 
@@ -83,6 +85,8 @@ static void coalesced_mmio_destructor(struct kvm_io_device *this)
 {
        struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
 
+       list_del(&dev->list);
+
        kfree(dev);
 }
 
@@ -93,7 +97,6 @@ static const struct kvm_io_device_ops coalesced_mmio_ops = {
 
 int kvm_coalesced_mmio_init(struct kvm *kvm)
 {
-       struct kvm_coalesced_mmio_dev *dev;
        struct page *page;
        int ret;
 
@@ -101,31 +104,18 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page)
                goto out_err;
-       kvm->coalesced_mmio_ring = page_address(page);
-
-       ret = -ENOMEM;
-       dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
-       if (!dev)
-               goto out_free_page;
-       spin_lock_init(&dev->lock);
-       kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
-       dev->kvm = kvm;
-       kvm->coalesced_mmio_dev = dev;
 
-       mutex_lock(&kvm->slots_lock);
-       ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev);
-       mutex_unlock(&kvm->slots_lock);
-       if (ret < 0)
-               goto out_free_dev;
+       ret = 0;
+       kvm->coalesced_mmio_ring = page_address(page);
 
-       return ret;
+       /*
+        * We're using this spinlock to sync access to the coalesced ring.
+        * The list doesn't need it's own lock since device registration and
+        * unregistration should only happen when kvm->slots_lock is held.
+        */
+       spin_lock_init(&kvm->ring_lock);
+       INIT_LIST_HEAD(&kvm->coalesced_zones);
 
-out_free_dev:
-       kvm->coalesced_mmio_dev = NULL;
-       kfree(dev);
-out_free_page:
-       kvm->coalesced_mmio_ring = NULL;
-       __free_page(page);
 out_err:
        return ret;
 }
@@ -139,51 +129,50 @@ void kvm_coalesced_mmio_free(struct kvm *kvm)
 int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
                                         struct kvm_coalesced_mmio_zone *zone)
 {
-       struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;
+       int ret;
+       struct kvm_coalesced_mmio_dev *dev;
 
-       if (dev == NULL)
-               return -ENXIO;
+       dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+
+       kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
+       dev->kvm = kvm;
+       dev->zone = *zone;
 
        mutex_lock(&kvm->slots_lock);
-       if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
-               mutex_unlock(&kvm->slots_lock);
-               return -ENOBUFS;
-       }
+       ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, zone->addr,
+                                     zone->size, &dev->dev);
+       if (ret < 0)
+               goto out_free_dev;
+       list_add_tail(&dev->list, &kvm->coalesced_zones);
+       mutex_unlock(&kvm->slots_lock);
 
-       dev->zone[dev->nb_zones] = *zone;
-       dev->nb_zones++;
+       return ret;
 
+out_free_dev:
        mutex_unlock(&kvm->slots_lock);
+
+       kfree(dev);
+
+       if (dev == NULL)
+               return -ENXIO;
+
        return 0;
 }
 
 int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
                                           struct kvm_coalesced_mmio_zone *zone)
 {
-       int i;
-       struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;
-       struct kvm_coalesced_mmio_zone *z;
-
-       if (dev == NULL)
-               return -ENXIO;
+       struct kvm_coalesced_mmio_dev *dev, *tmp;
 
        mutex_lock(&kvm->slots_lock);
 
-       i = dev->nb_zones;
-       while (i) {
-               z = &dev->zone[i - 1];
-
-               /* unregister all zones
-                * included in (zone->addr, zone->size)
-                */
-
-               if (zone->addr <= z->addr &&
-                   z->addr + z->size <= zone->addr + zone->size) {
-                       dev->nb_zones--;
-                       *z = dev->zone[dev->nb_zones];
+       list_for_each_entry_safe(dev, tmp, &kvm->coalesced_zones, list)
+               if (coalesced_mmio_in_range(dev, zone->addr, zone->size)) {
+                       kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dev->dev);
+                       kvm_iodevice_destructor(&dev->dev);
                }
-               i--;
-       }
 
        mutex_unlock(&kvm->slots_lock);