1 /* 2 * Page cache for QEMU 3 * The cache is base on a hash of the page address 4 * 5 * Copyright 2012 Red Hat, Inc. and/or its affiliates 6 * 7 * Authors: 8 * Orit Wasserman <owasserm@redhat.com> 9 * 10 * This work is licensed under the terms of the GNU GPL, version 2 or later. 11 * See the COPYING file in the top-level directory. 12 * 13 */ 14 15 #ifndef PAGE_CACHE_H 16 #define PAGE_CACHE_H 17 18 /* Page cache for storing guest pages */ 19 typedef struct PageCache PageCache; 20 21 /** 22 * cache_init: Initialize the page cache 23 * 24 * 25 * Returns new allocated cache or NULL on error 26 * 27 * @cache_size: cache size in bytes 28 * @page_size: cache page size 29 * @errp: set *errp if the check failed, with reason 30 */ 31 PageCache *cache_init(uint64_t cache_size, size_t page_size, Error **errp); 32 /** 33 * cache_fini: free all cache resources 34 * @cache pointer to the PageCache struct 35 */ 36 void cache_fini(PageCache *cache); 37 38 /** 39 * cache_is_cached: Checks to see if the page is cached 40 * 41 * Returns %true if page is cached 42 * 43 * @cache pointer to the PageCache struct 44 * @addr: page addr 45 * @current_age: current bitmap generation 46 */ 47 bool cache_is_cached(const PageCache *cache, uint64_t addr, 48 uint64_t current_age); 49 50 /** 51 * get_cached_data: Get the data cached for an addr 52 * 53 * Returns pointer to the data cached or NULL if not cached 54 * 55 * @cache pointer to the PageCache struct 56 * @addr: page addr 57 */ 58 uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); 59 60 /** 61 * cache_insert: insert the page into the cache. the page cache 62 * will dup the data on insert. the previous value will be overwritten 63 * 64 * Returns -1 when the page isn't inserted into cache 65 * 66 * @cache pointer to the PageCache struct 67 * @addr: page address 68 * @pdata: pointer to the page 69 * @current_age: current bitmap generation 70 */ 71 int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata, 72 uint64_t current_age); 73 74 #endif 75