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author | Orit Wasserman <owasserm@redhat.com> | 2012-08-06 21:42:50 +0300 |
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committer | Juan Quintela <quintela@redhat.com> | 2012-08-08 13:51:12 +0200 |
commit | 9fb26641ab497eda9138f9af75cbeb02ed59b5ae (patch) | |
tree | ad4374600d582b27542fc8677048aa3f17f156ed /include/qemu | |
parent | 34c26412b76840e0cab9808047e29aebd429c139 (diff) | |
download | qemu-9fb26641ab497eda9138f9af75cbeb02ed59b5ae.zip qemu-9fb26641ab497eda9138f9af75cbeb02ed59b5ae.tar.gz qemu-9fb26641ab497eda9138f9af75cbeb02ed59b5ae.tar.bz2 |
Add cache handling functions
Add MRU page cache mechanism.
The page are accessed by their address.
Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'include/qemu')
-rw-r--r-- | include/qemu/page_cache.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/qemu/page_cache.h b/include/qemu/page_cache.h new file mode 100644 index 0000000..3839ac7 --- /dev/null +++ b/include/qemu/page_cache.h @@ -0,0 +1,79 @@ +/* + * Page cache for QEMU + * The cache is base on a hash of the page address + * + * Copyright 2012 Red Hat, Inc. and/or its affiliates + * + * Authors: + * Orit Wasserman <owasserm@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#ifndef PAGE_CACHE_H +#define PAGE_CACHE_H + +/* Page cache for storing guest pages */ +typedef struct PageCache PageCache; + +/** + * cache_init: Initialize the page cache + * + * + * Returns new allocated cache or NULL on error + * + * @cache pointer to the PageCache struct + * @num_pages: cache maximal number of cached pages + * @page_size: cache page size + */ +PageCache *cache_init(int64_t num_pages, unsigned int page_size); + +/** + * cache_fini: free all cache resources + * @cache pointer to the PageCache struct + */ +void cache_fini(PageCache *cache); + +/** + * cache_is_cached: Checks to see if the page is cached + * + * Returns %true if page is cached + * + * @cache pointer to the PageCache struct + * @addr: page addr + */ +bool cache_is_cached(const PageCache *cache, uint64_t addr); + +/** + * get_cached_data: Get the data cached for an addr + * + * Returns pointer to the data cached or NULL if not cached + * + * @cache pointer to the PageCache struct + * @addr: page addr + */ +uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); + +/** + * cache_insert: insert the page into the cache. the previous value will be overwritten + * + * @cache pointer to the PageCache struct + * @addr: page address + * @pdata: pointer to the page + */ +void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); + +/** + * cache_resize: resize the page cache. In case of size reduction the extra + * pages will be freed + * + * Returns -1 on error new cache size on success + * + * @cache pointer to the PageCache struct + * @num_pages: new page cache size (in pages) + */ +int64_t cache_resize(PageCache *cache, int64_t num_pages); + +#endif |