From ec53500fae421e07c5d035918ca454a429732ef4 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 30 Oct 2013 11:02:17 -0600 Subject: 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 Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/devices/vfio.txt | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 Documentation/virtual/kvm/devices/vfio.txt (limited to 'Documentation/virtual/kvm') diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt new file mode 100644 index 000000000000..ef51740c67ca --- /dev/null +++ b/Documentation/virtual/kvm/devices/vfio.txt @@ -0,0 +1,22 @@ +VFIO virtual device +=================== + +Device types supported: + KVM_DEV_TYPE_VFIO + +Only one VFIO instance may be created per VM. The created device +tracks VFIO groups in use by the VM and features of those groups +important to the correctness and acceleration of the VM. As groups +are enabled and disabled for use by the VM, KVM should be updated +about their presence. When registered with KVM, a reference to the +VFIO-group is held by KVM. + +Groups: + KVM_DEV_VFIO_GROUP + +KVM_DEV_VFIO_GROUP attributes: + KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking + KVM_DEV_VFIO_GROUP_DEL: Remove a VFIO group from VFIO-KVM device tracking + +For each, kvm_device_attr.addr points to an int32_t file descriptor +for the VFIO group. -- cgit v1.2.3