Merge tag 'sunxi-fixes-for-4.3' of https://git.kernel.org/pub/scm/linux/kernel/git...

[linux-drm-fsl-dcu.git] / virt / kvm / eventfd.c

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 9ff4193dfa493c3e226c3fd554061b171ca7b9c5..79db45336e3a25cb15696ca8659a87572e168585 100644 (file)
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -771,40 +771,14 @@ static enum kvm_bus ioeventfd_bus_from_flags(__u32 flags)
        return KVM_MMIO_BUS;
 }
 
-static int
-kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+static int kvm_assign_ioeventfd_idx(struct kvm *kvm,
+                               enum kvm_bus bus_idx,
+                               struct kvm_ioeventfd *args)
 {
-       enum kvm_bus              bus_idx;
-       struct _ioeventfd        *p;
-       struct eventfd_ctx       *eventfd;
-       int                       ret;
-
-       bus_idx = ioeventfd_bus_from_flags(args->flags);
-       /* must be natural-word sized, or 0 to ignore length */
-       switch (args->len) {
-       case 0:
-       case 1:
-       case 2:
-       case 4:
-       case 8:
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       /* check for range overflow */
-       if (args->addr + args->len < args->addr)
-               return -EINVAL;
 
-       /* check for extra flags that we don't understand */
-       if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
-               return -EINVAL;
-
-       /* ioeventfd with no length can't be combined with DATAMATCH */
-       if (!args->len &&
-           args->flags & (KVM_IOEVENTFD_FLAG_PIO |
-                          KVM_IOEVENTFD_FLAG_DATAMATCH))
-               return -EINVAL;
+       struct eventfd_ctx *eventfd;
+       struct _ioeventfd *p;
+       int ret;
 
        eventfd = eventfd_ctx_fdget(args->fd);
        if (IS_ERR(eventfd))
@@ -843,16 +817,6 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
        if (ret < 0)
                goto unlock_fail;
 
-       /* When length is ignored, MMIO is also put on a separate bus, for
-        * faster lookups.
-        */
-       if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) {
-               ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS,
-                                             p->addr, 0, &p->dev);
-               if (ret < 0)
-                       goto register_fail;
-       }
-
        kvm->buses[bus_idx]->ioeventfd_count++;
        list_add_tail(&p->list, &kvm->ioeventfds);
 
@@ -860,8 +824,6 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 
        return 0;
 
-register_fail:
-       kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
 unlock_fail:
        mutex_unlock(&kvm->slots_lock);
 
@@ -873,14 +835,13 @@ fail:
 }
 
 static int
-kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
+                          struct kvm_ioeventfd *args)
 {
-       enum kvm_bus              bus_idx;
        struct _ioeventfd        *p, *tmp;
        struct eventfd_ctx       *eventfd;
        int                       ret = -ENOENT;
 
-       bus_idx = ioeventfd_bus_from_flags(args->flags);
        eventfd = eventfd_ctx_fdget(args->fd);
        if (IS_ERR(eventfd))
                return PTR_ERR(eventfd);
@@ -901,10 +862,6 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
                        continue;
 
                kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
-               if (!p->length) {
-                       kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS,
-                                                 &p->dev);
-               }
                kvm->buses[bus_idx]->ioeventfd_count--;
                ioeventfd_release(p);
                ret = 0;
@@ -918,6 +875,71 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
        return ret;
 }
 
+static int kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+       enum kvm_bus bus_idx = ioeventfd_bus_from_flags(args->flags);
+       int ret = kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
+
+       if (!args->len && bus_idx == KVM_MMIO_BUS)
+               kvm_deassign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
+
+       return ret;
+}
+
+static int
+kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+       enum kvm_bus              bus_idx;
+       int ret;
+
+       bus_idx = ioeventfd_bus_from_flags(args->flags);
+       /* must be natural-word sized, or 0 to ignore length */
+       switch (args->len) {
+       case 0:
+       case 1:
+       case 2:
+       case 4:
+       case 8:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       /* check for range overflow */
+       if (args->addr + args->len < args->addr)
+               return -EINVAL;
+
+       /* check for extra flags that we don't understand */
+       if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
+               return -EINVAL;
+
+       /* ioeventfd with no length can't be combined with DATAMATCH */
+       if (!args->len &&
+           args->flags & (KVM_IOEVENTFD_FLAG_PIO |
+                          KVM_IOEVENTFD_FLAG_DATAMATCH))
+               return -EINVAL;
+
+       ret = kvm_assign_ioeventfd_idx(kvm, bus_idx, args);
+       if (ret)
+               goto fail;
+
+       /* When length is ignored, MMIO is also put on a separate bus, for
+        * faster lookups.
+        */
+       if (!args->len && bus_idx == KVM_MMIO_BUS) {
+               ret = kvm_assign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
+               if (ret < 0)
+                       goto fast_fail;
+       }
+
+       return 0;
+
+fast_fail:
+       kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
+fail:
+       return ret;
+}
+
 int
 kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 {