kvm: factor out core eventfd assign/deassign logic

This patch factors out core eventfd assign/deassign logic and leaves
the argument checking and bus index selection to callers.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index e404806e3a7afc7901c7c057737f163afaeffac6..0829c7f197a0d97e970a5ec224729e7f4395815b 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))
@@ -873,14 +847,13 @@ 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);
@@ -918,6 +891,48 @@ 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);
+
+       return kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
+}
+
+static int
+kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+       enum kvm_bus              bus_idx;
+
+       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;
+
+       return kvm_assign_ioeventfd_idx(kvm, bus_idx, args);
+}
+
 int
 kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 {