linux/include/xen/balloon.h
Boris Ostrovsky b3cf8528bb xen/balloon: Mark unallocated host memory as UNUSABLE
Commit f5775e0b61 ("x86/xen: discard RAM regions above the maximum
reservation") left host memory not assigned to dom0 as available for
memory hotplug.

Unfortunately this also meant that those regions could be used by
others. Specifically, commit fa564ad963 ("x86/PCI: Enable a 64bit BAR
on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") may try to map those
addresses as MMIO.

To prevent this mark unallocated host memory as E820_TYPE_UNUSABLE (thus
effectively reverting f5775e0b61) and keep track of that region as
a hostmem resource that can be used for the hotplug.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2017-12-20 13:16:20 -05:00

51 lines
1.2 KiB
C

/******************************************************************************
* Xen balloon functionality
*/
#define RETRY_UNLIMITED 0
struct balloon_stats {
/* We aim for 'current allocation' == 'target allocation'. */
unsigned long current_pages;
unsigned long target_pages;
unsigned long target_unpopulated;
/* Number of pages in high- and low-memory balloons. */
unsigned long balloon_low;
unsigned long balloon_high;
unsigned long total_pages;
unsigned long schedule_delay;
unsigned long max_schedule_delay;
unsigned long retry_count;
unsigned long max_retry_count;
};
extern struct balloon_stats balloon_stats;
void balloon_set_new_target(unsigned long target);
int alloc_xenballooned_pages(int nr_pages, struct page **pages);
void free_xenballooned_pages(int nr_pages, struct page **pages);
struct device;
#ifdef CONFIG_XEN_SELFBALLOONING
extern int register_xen_selfballooning(struct device *dev);
#else
static inline int register_xen_selfballooning(struct device *dev)
{
return -ENOSYS;
}
#endif
#ifdef CONFIG_XEN_BALLOON
void xen_balloon_init(void);
#else
static inline void xen_balloon_init(void)
{
}
#endif
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
struct resource;
void arch_xen_balloon_init(struct resource *hostmem_resource);
#endif