1607ca46eSDavid Howells #ifndef _LINUX_VIRTIO_BALLOON_H 2607ca46eSDavid Howells #define _LINUX_VIRTIO_BALLOON_H 3607ca46eSDavid Howells /* This header is BSD licensed so anyone can use the definitions to implement 4607ca46eSDavid Howells * compatible drivers/servers. 5607ca46eSDavid Howells * 6607ca46eSDavid Howells * Redistribution and use in source and binary forms, with or without 7607ca46eSDavid Howells * modification, are permitted provided that the following conditions 8607ca46eSDavid Howells * are met: 9607ca46eSDavid Howells * 1. Redistributions of source code must retain the above copyright 10607ca46eSDavid Howells * notice, this list of conditions and the following disclaimer. 11607ca46eSDavid Howells * 2. Redistributions in binary form must reproduce the above copyright 12607ca46eSDavid Howells * notice, this list of conditions and the following disclaimer in the 13607ca46eSDavid Howells * documentation and/or other materials provided with the distribution. 14607ca46eSDavid Howells * 3. Neither the name of IBM nor the names of its contributors 15607ca46eSDavid Howells * may be used to endorse or promote products derived from this software 16607ca46eSDavid Howells * without specific prior written permission. 17607ca46eSDavid Howells * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND 18607ca46eSDavid Howells * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19607ca46eSDavid Howells * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20607ca46eSDavid Howells * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 21607ca46eSDavid Howells * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22607ca46eSDavid Howells * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23607ca46eSDavid Howells * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24607ca46eSDavid Howells * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25607ca46eSDavid Howells * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26607ca46eSDavid Howells * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27607ca46eSDavid Howells * SUCH DAMAGE. */ 28df81b29cSMichael S. Tsirkin #include <linux/types.h> 298a7b19d8SMikko Rapeli #include <linux/virtio_types.h> 30607ca46eSDavid Howells #include <linux/virtio_ids.h> 31607ca46eSDavid Howells #include <linux/virtio_config.h> 32607ca46eSDavid Howells 33607ca46eSDavid Howells /* The feature bitmap for virtio balloon */ 34607ca46eSDavid Howells #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ 35607ca46eSDavid Howells #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ 365a10b7dbSRaushaniya Maksudova #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ 37607ca46eSDavid Howells 38607ca46eSDavid Howells /* Size of a PFN in the balloon interface. */ 39607ca46eSDavid Howells #define VIRTIO_BALLOON_PFN_SHIFT 12 40607ca46eSDavid Howells 4125e65e4eSMichael S. Tsirkin struct virtio_balloon_config { 42607ca46eSDavid Howells /* Number of pages host wants Guest to give up. */ 43df81b29cSMichael S. Tsirkin __u32 num_pages; 44607ca46eSDavid Howells /* Number of pages we've actually got in balloon. */ 45df81b29cSMichael S. Tsirkin __u32 actual; 46607ca46eSDavid Howells }; 47607ca46eSDavid Howells 48607ca46eSDavid Howells #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ 49607ca46eSDavid Howells #define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */ 50607ca46eSDavid Howells #define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */ 51607ca46eSDavid Howells #define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */ 52607ca46eSDavid Howells #define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */ 53607ca46eSDavid Howells #define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */ 54*5057dcd0SIgor Redko #define VIRTIO_BALLOON_S_AVAIL 6 /* Available memory as in /proc */ 55*5057dcd0SIgor Redko #define VIRTIO_BALLOON_S_NR 7 56607ca46eSDavid Howells 57df81b29cSMichael S. Tsirkin /* 58df81b29cSMichael S. Tsirkin * Memory statistics structure. 59df81b29cSMichael S. Tsirkin * Driver fills an array of these structures and passes to device. 60df81b29cSMichael S. Tsirkin * 61df81b29cSMichael S. Tsirkin * NOTE: fields are laid out in a way that would make compiler add padding 62df81b29cSMichael S. Tsirkin * between and after fields, so we have to use compiler-specific attributes to 63df81b29cSMichael S. Tsirkin * pack it, to disable this padding. This also often causes compiler to 64df81b29cSMichael S. Tsirkin * generate suboptimal code. 65df81b29cSMichael S. Tsirkin * 66df81b29cSMichael S. Tsirkin * We maintain this statistics structure format for backwards compatibility, 67df81b29cSMichael S. Tsirkin * but don't follow this example. 68df81b29cSMichael S. Tsirkin * 69df81b29cSMichael S. Tsirkin * If implementing a similar structure, do something like the below instead: 70df81b29cSMichael S. Tsirkin * struct virtio_balloon_stat { 71df81b29cSMichael S. Tsirkin * __virtio16 tag; 72df81b29cSMichael S. Tsirkin * __u8 reserved[6]; 73df81b29cSMichael S. Tsirkin * __virtio64 val; 74df81b29cSMichael S. Tsirkin * }; 75df81b29cSMichael S. Tsirkin * 76df81b29cSMichael S. Tsirkin * In other words, add explicit reserved fields to align field and 77df81b29cSMichael S. Tsirkin * structure boundaries at field size, avoiding compiler padding 78df81b29cSMichael S. Tsirkin * without the packed attribute. 79df81b29cSMichael S. Tsirkin */ 80607ca46eSDavid Howells struct virtio_balloon_stat { 81df81b29cSMichael S. Tsirkin __virtio16 tag; 82df81b29cSMichael S. Tsirkin __virtio64 val; 83607ca46eSDavid Howells } __attribute__((packed)); 84607ca46eSDavid Howells 85607ca46eSDavid Howells #endif /* _LINUX_VIRTIO_BALLOON_H */ 86