name : virtio_balloon.h #ifndef _LINUX_VIRTIO_BALLOON_H #define _LINUX_VIRTIO_BALLOON_H /* This header is BSD licensed so anyone can use the definitions to implement * compatible drivers/servers. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of IBM nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <linux/types.h> #include <linux/virtio_types.h> #include <linux/virtio_ids.h> #include <linux/virtio_config.h> /* The feature bitmap for virtio balloon */ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ #define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */ #define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */ #define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */ /* Size of a PFN in the balloon interface. */ #define VIRTIO_BALLOON_PFN_SHIFT 12 #define VIRTIO_BALLOON_CMD_ID_STOP 0 #define VIRTIO_BALLOON_CMD_ID_DONE 1 struct virtio_balloon_config { /* Number of pages host wants Guest to give up. */ __u32 num_pages; /* Number of pages we've actually got in balloon. */ __u32 actual; /* * Free page hint command id, readonly by guest. * Was previously named free_page_report_cmd_id so we * need to carry that name for legacy support. */ union { __u32 free_page_hint_cmd_id; __u32 free_page_report_cmd_id; /* deprecated */ }; /* Stores PAGE_POISON if page poisoning is in use */ __u32 poison_val; }; #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ #define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */ #define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */ #define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */ #define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */ #define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */ #define VIRTIO_BALLOON_S_AVAIL 6 /* Available memory as in /proc */ #define VIRTIO_BALLOON_S_CACHES 7 /* Disk caches */ #define VIRTIO_BALLOON_S_HTLB_PGALLOC 8 /* Hugetlb page allocations */ #define VIRTIO_BALLOON_S_HTLB_PGFAIL 9 /* Hugetlb page allocation failures */ #define VIRTIO_BALLOON_S_NR 10 #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \ VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \ VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \ VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \ VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \ VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \ VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \ VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \ VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \ VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \ VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures" \ } #define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("") /* * Memory statistics structure. * Driver fills an array of these structures and passes to device. * * NOTE: fields are laid out in a way that would make compiler add padding * between and after fields, so we have to use compiler-specific attributes to * pack it, to disable this padding. This also often causes compiler to * generate suboptimal code. * * We maintain this statistics structure format for backwards compatibility, * but don't follow this example. * * If implementing a similar structure, do something like the below instead: * struct virtio_balloon_stat { * __virtio16 tag; * __u8 reserved[6]; * __virtio64 val; * }; * * In other words, add explicit reserved fields to align field and * structure boundaries at field size, avoiding compiler padding * without the packed attribute. */ struct virtio_balloon_stat { __virtio16 tag; __virtio64 val; } __attribute__((packed)); #endif /* _LINUX_VIRTIO_BALLOON_H */