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 pointer to the PageCache struct 28 * @num_pages: cache maximal number of cached pages 29 * @page_size: cache page size 30 */ 31 PageCache *cache_init(int64_t num_pages, unsigned int page_size); 32 33 /** 34 * cache_fini: free all cache resources 35 * @cache pointer to the PageCache struct 36 */ 37 void cache_fini(PageCache *cache); 38 39 /** 40 * cache_is_cached: Checks to see if the page is cached 41 * 42 * Returns %true if page is cached 43 * 44 * @cache pointer to the PageCache struct 45 * @addr: page addr 46 * @current_age: current bitmap generation 47 */ 48 bool cache_is_cached(const PageCache *cache, uint64_t addr, 49 uint64_t current_age); 50 51 /** 52 * get_cached_data: Get the data cached for an addr 53 * 54 * Returns pointer to the data cached or NULL if not cached 55 * 56 * @cache pointer to the PageCache struct 57 * @addr: page addr 58 */ 59 uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); 60 61 /** 62 * cache_insert: insert the page into the cache. the page cache 63 * will dup the data on insert. the previous value will be overwritten 64 * 65 * Returns -1 when the page isn't inserted into cache 66 * 67 * @cache pointer to the PageCache struct 68 * @addr: page address 69 * @pdata: pointer to the page 70 * @current_age: current bitmap generation 71 */ 72 int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata, 73 uint64_t current_age); 74 75 #endif 76