#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
+#include <xen/xen.h>
#include <xen/page.h>
#include <xen/interface/callback.h>
+#include <xen/interface/memory.h>
#include <xen/interface/physdev.h>
#include <xen/interface/memory.h>
#include <xen/features.h>
extern void xen_syscall_target(void);
extern void xen_syscall32_target(void);
+/* Amount of extra memory space we add to the e820 ranges */
+phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+
+/*
+ * The maximum amount of extra memory compared to the base size. The
+ * main scaling factor is the size of struct page. At extreme ratios
+ * of base:extra, all the base memory can be filled with page
+ * structures for the extra memory, leaving no space for anything
+ * else.
+ *
+ * 10x seems like a reasonable balance between scaling flexibility and
+ * leaving a practically usable system.
+ */
+#define EXTRA_MEM_RATIO (10)
+
+static __init void xen_add_extra_mem(unsigned long pages)
+{
+ u64 size = (u64)pages * PAGE_SIZE;
+ u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
+
+ if (!pages)
+ return;
+
+ e820_add_region(extra_start, size, E820_RAM);
+ sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+
+ memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
+
+ xen_extra_mem_size += size;
+
+ xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
+}
+
static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
phys_addr_t end_addr)
{
const struct e820map *e820)
{
phys_addr_t max_addr = PFN_PHYS(max_pfn);
- phys_addr_t last_end = 0;
+ phys_addr_t last_end = ISA_END_ADDRESS;
unsigned long released = 0;
int i;
+ /* Free any unused memory above the low 1Mbyte. */
for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
phys_addr_t end = e820->map[i].addr;
end = min(max_addr, end);
- released += xen_release_chunk(last_end, end);
- last_end = e820->map[i].addr + e820->map[i].size;
+ if (last_end < end)
+ released += xen_release_chunk(last_end, end);
+ last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
}
if (last_end < max_addr)
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
**/
-
char * __init xen_memory_setup(void)
{
+ static struct e820entry map[E820MAX] __initdata;
+
unsigned long max_pfn = xen_start_info->nr_pages;
+ unsigned long long mem_end;
+ int rc;
+ struct xen_memory_map memmap;
+ unsigned long extra_pages = 0;
+ unsigned long extra_limit;
+ int i;
+ int op;
max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
+ mem_end = PFN_PHYS(max_pfn);
+
+ memmap.nr_entries = E820MAX;
+ set_xen_guest_handle(memmap.buffer, map);
+
+ op = xen_initial_domain() ?
+ XENMEM_machine_memory_map :
+ XENMEM_memory_map;
+ rc = HYPERVISOR_memory_op(op, &memmap);
+ if (rc == -ENOSYS) {
+ BUG_ON(xen_initial_domain());
+ memmap.nr_entries = 1;
+ map[0].addr = 0ULL;
+ map[0].size = mem_end;
+ /* 8MB slack (to balance backend allocations). */
+ map[0].size += 8ULL << 20;
+ map[0].type = E820_RAM;
+ rc = 0;
+ }
+ BUG_ON(rc);
e820.nr_map = 0;
+ xen_extra_mem_start = mem_end;
+ for (i = 0; i < memmap.nr_entries; i++) {
+ unsigned long long end = map[i].addr + map[i].size;
+
+ if (map[i].type == E820_RAM) {
+ if (map[i].addr < mem_end && end > mem_end) {
+ /* Truncate region to max_mem. */
+ u64 delta = end - mem_end;
- e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
+ map[i].size -= delta;
+ extra_pages += PFN_DOWN(delta);
+
+ end = mem_end;
+ }
+ }
+
+ if (end > xen_extra_mem_start)
+ xen_extra_mem_start = end;
+
+ /* If region is non-RAM or below mem_end, add what remains */
+ if ((map[i].type != E820_RAM || map[i].addr < mem_end) &&
+ map[i].size > 0)
+ e820_add_region(map[i].addr, map[i].size, map[i].type);
+ }
/*
- * Even though this is normal, usable memory under Xen, reserve
- * ISA memory anyway because too many things think they can poke
+ * In domU, the ISA region is normal, usable memory, but we
+ * reserve ISA memory anyway because too many things poke
* about in there.
+ *
+ * In Dom0, the host E820 information can leave gaps in the
+ * ISA range, which would cause us to release those pages. To
+ * avoid this, we unconditionally reserve them here.
*/
e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
E820_RESERVED);
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
- xen_return_unused_memory(xen_start_info->nr_pages, &e820);
+ extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
+
+ /*
+ * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
+ * factor the base size. On non-highmem systems, the base
+ * size is the full initial memory allocation; on highmem it
+ * is limited to the max size of lowmem, so that it doesn't
+ * get completely filled.
+ *
+ * In principle there could be a problem in lowmem systems if
+ * the initial memory is also very large with respect to
+ * lowmem, but we won't try to deal with that here.
+ */
+ extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+ max_pfn + extra_pages);
+
+ if (extra_limit >= max_pfn)
+ extra_pages = extra_limit - max_pfn;
+ else
+ extra_pages = 0;
+
+ if (!xen_initial_domain())
+ xen_add_extra_mem(extra_pages);
return "Xen";
}
pm_idle = xen_idle;
- paravirt_disable_iospace();
-
fiddle_vdso();
}
git.openpandora.org / pandora-kernel.git / blobdiff