kvm: Add VFIO device

So far we've succeeded at making KVM and VFIO mostly unaware of each
other, but areas are cropping up where a connection beyond eventfds
and irqfds needs to be made.  This patch introduces a KVM-VFIO device
that is meant to be a gateway for such interaction.  The user creates
the device and can add and remove VFIO groups to it via file
descriptors.  When a group is added, KVM verifies the group is valid
and gets a reference to it via the VFIO external user interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 32c60b98ddf8..509cfbfe9658 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -845,6 +845,10 @@ struct kvm_device_attr {
 #define KVM_DEV_TYPE_FSL_MPIC_20        1
 #define KVM_DEV_TYPE_FSL_MPIC_42        2
 #define KVM_DEV_TYPE_XICS               3
+#define KVM_DEV_TYPE_VFIO               4
+#define  KVM_DEV_VFIO_GROUP                     1
+#define   KVM_DEV_VFIO_GROUP_ADD                        1
+#define   KVM_DEV_VFIO_GROUP_DEL                        2
 
 /*
  * ioctls for VM fds