uapi/linux/virtio_mem.h

1 /* SPDX-License-Identifier: BSD-3-Clause */
3  * Virtio Mem Device
47  * Each virtio-mem device manages a dedicated region in physical address
48  * space. Each device can belong to a single NUMA node, multiple devices
49  * for a single NUMA node are possible. A virtio-mem device is like a
51  * or unplugged. The device driver is responsible for (un)plugging memory
54  * Virtio-mem devices can only operate on their assigned memory region in
55  * order to (un)plug memory. A device cannot (un)plug memory belonging to
59  * be provided by a device. The "size" corresponds to the amount of memory
61  * from the device to the device driver to (un)plug blocks. The
62  * device driver should try to (un)plug blocks in order to reach the
76  * It can happen that the device cannot process a request, because it is
77  * busy. The device driver has to retry later.
80  * device driver can start with a clean state. However, in specific
81  * scenarios (if the device is busy) it can happen that the device still
82  * has memory plugged. The device driver can request to unplug all memory
83  * (VIRTIO_MEM_REQ_UNPLUG) - which might take a while to succeed if the
84  * device is busy.
87 /* --- virtio-mem: feature bits --- */
97 /* --- virtio-mem: guest -> host requests --- */
138 /* --- virtio-mem: host -> guest response --- */
142  * - VIRTIO_MEM_REQ_PLUG
143  * - VIRTIO_MEM_REQ_UNPLUG
144  * - VIRTIO_MEM_REQ_UNPLUG_ALL
145  * - VIRTIO_MEM_REQ_STATE
149  * Request denied - e.g. trying to plug more than requested, applicable for
150  * - VIRTIO_MEM_REQ_PLUG
155  * - VIRTIO_MEM_REQ_PLUG
156  * - VIRTIO_MEM_REQ_UNPLUG
157  * - VIRTIO_MEM_REQ_UNPLUG_ALL
162  * - VIRTIO_MEM_REQ_PLUG
163  * - VIRTIO_MEM_REQ_UNPLUG
164  * - VIRTIO_MEM_REQ_STATE
189 /* --- virtio-mem: configuration --- */