cd9151e26d
Currently ballooned out pages are mapped to 0 and have INVALID_P2M_ENTRY in the p2m. These ballooned out pages are used to map foreign grants by gntdev and blkback (see alloc_xenballooned_pages). Allocate a page per cpu and map all the ballooned out pages to the corresponding mfn. Set the p2m accordingly. This way reading from a ballooned out page won't cause a kernel crash (see http://lists.xen.org/archives/html/xen-devel/2012-12/msg01154.html). Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> CC: alex@alex.org.uk CC: dcrisan@flexiant.com Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
/******************************************************************************
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* Xen balloon functionality
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*/
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#define RETRY_UNLIMITED 0
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struct balloon_stats {
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/* We aim for 'current allocation' == 'target allocation'. */
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unsigned long current_pages;
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unsigned long target_pages;
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/* Number of pages in high- and low-memory balloons. */
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unsigned long balloon_low;
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unsigned long balloon_high;
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unsigned long schedule_delay;
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unsigned long max_schedule_delay;
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unsigned long retry_count;
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unsigned long max_retry_count;
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#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
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unsigned long hotplug_pages;
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unsigned long balloon_hotplug;
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#endif
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};
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extern struct balloon_stats balloon_stats;
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void balloon_set_new_target(unsigned long target);
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int alloc_xenballooned_pages(int nr_pages, struct page **pages,
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bool highmem);
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void free_xenballooned_pages(int nr_pages, struct page **pages);
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struct page *get_balloon_scratch_page(void);
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void put_balloon_scratch_page(void);
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struct device;
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#ifdef CONFIG_XEN_SELFBALLOONING
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extern int register_xen_selfballooning(struct device *dev);
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#else
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static inline int register_xen_selfballooning(struct device *dev)
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{
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return -ENOSYS;
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}
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#endif
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