2 files changed, 50 insertions, 75 deletions

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index ae075dc0890d..2316ec1aadc4 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -24,23 +24,13 @@ 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;
-        int i;
-
-        /* 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)
-                 */
+        /* is it in a batchable area ?
+         * (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 (dev->zone.addr <= addr &&
+                addr + len <= dev->zone.addr + dev->zone.size);
 }
 
 static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
@@ -73,10 +63,10 @@ static int coalesced_mmio_write(struct kvm_io_device *this,
         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->lock);
+                spin_unlock(&dev->kvm->ring_lock);
                 return -EOPNOTSUPP;
         }
 
@@ -87,7 +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;
 }
 
@@ -95,6 +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);
 }
 
@@ -105,7 +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;
 
@@ -113,31 +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;
 }
@@ -151,51 +129,49 @@ 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, &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);
 
diff --git a/virt/kvm/coalesced_mmio.h b/virt/kvm/coalesced_mmio.h
index 8a5959e3535f..b280c20444d1 100644
--- a/virt/kvm/coalesced_mmio.h
+++ b/virt/kvm/coalesced_mmio.h
@@ -12,14 +12,13 @@
 
 #ifdef CONFIG_KVM_MMIO
 
-#define KVM_COALESCED_MMIO_ZONE_MAX 100
+#include <linux/list.h>
 
 struct kvm_coalesced_mmio_dev {
+        struct list_head list;
         struct kvm_io_device dev;
         struct kvm *kvm;
-        spinlock_t lock;
-        int nb_zones;
-        struct kvm_coalesced_mmio_zone zone[KVM_COALESCED_MMIO_ZONE_MAX];
+        struct kvm_coalesced_mmio_zone zone;
 };
 
 int kvm_coalesced_mmio_init(struct kvm *kvm);