xen: allocate p2m size based on actual max size
Allocate p2m tables based on the actual runtime maximum pfn rather than
the static config-time limit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index ecbdcf0..151813d9 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -169,25 +169,27 @@
*/
#define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
+static unsigned long max_p2m_pfn __read_mostly = MAX_DOMAIN_PAGES;
-#define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
-#define TOP_ENTRIES (MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE)
+#define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
+#define TOP_ENTRIES(pages) ((pages) / P2M_ENTRIES_PER_PAGE)
+#define MAX_TOP_ENTRIES TOP_ENTRIES(MAX_DOMAIN_PAGES)
/* Placeholder for holes in the address space */
static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_ENTRIES_PER_PAGE);
/* Array of pointers to pages containing p2m entries */
-static RESERVE_BRK_ARRAY(unsigned long *, p2m_top, TOP_ENTRIES);
+static RESERVE_BRK_ARRAY(unsigned long *, p2m_top, MAX_TOP_ENTRIES);
/* Arrays of p2m arrays expressed in mfns used for save/restore */
-static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, TOP_ENTRIES);
+static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, MAX_TOP_ENTRIES);
static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn_list,
- (TOP_ENTRIES / P2M_ENTRIES_PER_PAGE));
+ (MAX_TOP_ENTRIES / P2M_ENTRIES_PER_PAGE));
static inline unsigned p2m_top_index(unsigned long pfn)
{
- BUG_ON(pfn >= MAX_DOMAIN_PAGES);
+ BUG_ON(pfn >= max_p2m_pfn);
return pfn / P2M_ENTRIES_PER_PAGE;
}
@@ -201,13 +203,15 @@
{
unsigned pfn, idx;
- for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) {
+ for (pfn = 0; pfn < max_p2m_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_top[topidx]);
}
- for (idx = 0; idx < TOP_ENTRIES/P2M_ENTRIES_PER_PAGE; idx++) {
+ for (idx = 0;
+ idx < TOP_ENTRIES(max_p2m_pfn)/P2M_ENTRIES_PER_PAGE;
+ idx++) {
unsigned topidx = idx * P2M_ENTRIES_PER_PAGE;
p2m_top_mfn_list[idx] = virt_to_mfn(&p2m_top_mfn[topidx]);
}
@@ -230,19 +234,22 @@
unsigned pfn;
unsigned i;
+ max_p2m_pfn = max_pfn;
+
p2m_missing = extend_brk(sizeof(*p2m_missing) * P2M_ENTRIES_PER_PAGE,
PAGE_SIZE);
for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++)
p2m_missing[i] = ~0UL;
- p2m_top = extend_brk(sizeof(*p2m_top) * TOP_ENTRIES,
+ p2m_top = extend_brk(sizeof(*p2m_top) * TOP_ENTRIES(max_pfn),
PAGE_SIZE);
- for (i = 0; i < TOP_ENTRIES; i++)
+ for (i = 0; i < TOP_ENTRIES(max_pfn); i++)
p2m_top[i] = p2m_missing;
- p2m_top_mfn = extend_brk(sizeof(*p2m_top_mfn) * TOP_ENTRIES, PAGE_SIZE);
+ p2m_top_mfn = extend_brk(sizeof(*p2m_top_mfn) * TOP_ENTRIES(max_pfn),
+ PAGE_SIZE);
p2m_top_mfn_list = extend_brk(sizeof(*p2m_top_mfn_list) *
- (TOP_ENTRIES / P2M_ENTRIES_PER_PAGE),
+ (TOP_ENTRIES(max_pfn) / P2M_ENTRIES_PER_PAGE),
PAGE_SIZE);
for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
@@ -258,7 +265,7 @@
{
unsigned topidx, idx;
- if (unlikely(pfn >= MAX_DOMAIN_PAGES))
+ if (unlikely(pfn >= max_p2m_pfn))
return INVALID_P2M_ENTRY;
topidx = p2m_top_index(pfn);
@@ -304,7 +311,7 @@
{
unsigned topidx, idx;
- if (unlikely(pfn >= MAX_DOMAIN_PAGES)) {
+ if (unlikely(pfn >= max_p2m_pfn)) {
BUG_ON(mfn != INVALID_P2M_ENTRY);
return true;
}