87 lines
2.2 KiB
C
87 lines
2.2 KiB
C
/*
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* Page cache for QEMU
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* The cache is base on a hash of the page address
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*
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* Copyright 2012 Red Hat, Inc. and/or its affiliates
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*
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* Authors:
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* Orit Wasserman <owasserm@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#ifndef PAGE_CACHE_H
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#define PAGE_CACHE_H
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/* Page cache for storing guest pages */
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typedef struct PageCache PageCache;
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/**
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* cache_init: Initialize the page cache
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*
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*
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* Returns new allocated cache or NULL on error
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*
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* @cache pointer to the PageCache struct
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* @num_pages: cache maximal number of cached pages
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* @page_size: cache page size
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*/
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PageCache *cache_init(int64_t num_pages, unsigned int page_size);
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/**
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* cache_fini: free all cache resources
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* @cache pointer to the PageCache struct
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*/
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void cache_fini(PageCache *cache);
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/**
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* cache_is_cached: Checks to see if the page is cached
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*
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* Returns %true if page is cached
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*
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* @cache pointer to the PageCache struct
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* @addr: page addr
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* @current_age: current bitmap generation
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*/
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bool cache_is_cached(const PageCache *cache, uint64_t addr,
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uint64_t current_age);
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/**
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* get_cached_data: Get the data cached for an addr
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*
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* Returns pointer to the data cached or NULL if not cached
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*
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* @cache pointer to the PageCache struct
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* @addr: page addr
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*/
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uint8_t *get_cached_data(const PageCache *cache, uint64_t addr);
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/**
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* cache_insert: insert the page into the cache. the page cache
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* will dup the data on insert. the previous value will be overwritten
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*
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* Returns -1 when the page isn't inserted into cache
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*
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* @cache pointer to the PageCache struct
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* @addr: page address
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* @pdata: pointer to the page
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* @current_age: current bitmap generation
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*/
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int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata,
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uint64_t current_age);
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/**
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* cache_resize: resize the page cache. In case of size reduction the extra
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* pages will be freed
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*
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* Returns -1 on error new cache size on success
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*
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* @cache pointer to the PageCache struct
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* @num_pages: new page cache size (in pages)
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*/
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int64_t cache_resize(PageCache *cache, int64_t num_pages);
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#endif
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