# HG changeset patch
# User Alex Williamson <alex.williamson@xxxxxx>
# Date 1181581325 21600
# Node ID 9c96ff147be6b73109e4d0bae407c8cc0b501d59
# Parent 96331db61e47065da5d374a9ec432d6837aaf5af
[IA64] Fix p2m exposure.
p2m table page doesn't belong to any domain so that special handling required.
Instead, dom_p2m is introduced and make all p2m page belong to dom_p2m.
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
xen/arch/ia64/xen/mm.c | 54 +++++++++++++++++++++++++++++++++----------------
1 files changed, 37 insertions(+), 17 deletions(-)
diff -r 96331db61e47 -r 9c96ff147be6 xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c Wed Jun 06 09:30:01 2007 -0600
+++ b/xen/arch/ia64/xen/mm.c Mon Jun 11 11:02:05 2007 -0600
@@ -187,6 +187,13 @@ extern unsigned long ia64_iobase;
static struct domain *dom_xen, *dom_io;
+/*
+ * This number is bigger than DOMID_SELF, DOMID_XEN and DOMID_IO.
+ * If more reserved domain ids are introduced, this might be increased.
+ */
+#define DOMID_P2M (0x7FF8U)
+static struct domain *dom_p2m;
+
// followings are stolen from arch_init_memory() @ xen/arch/x86/mm.c
void
alloc_dom_xen_and_dom_io(void)
@@ -227,11 +234,8 @@ mm_teardown_pte(struct domain* d, volati
if (!mfn_valid(mfn))
return;
page = mfn_to_page(mfn);
- // page might be pte page for p2m exposing. check it.
- if (page_get_owner(page) == NULL) {
- BUG_ON(page->count_info != 0);
- return;
- }
+ BUG_ON(page_get_owner(page) == NULL);
+
// struct page_info corresponding to mfn may exist or not depending
// on CONFIG_VIRTUAL_FRAME_TABLE.
// The above check is too easy.
@@ -1379,10 +1383,19 @@ dom0vp_add_physmap_with_gmfn(struct doma
#ifdef CONFIG_XEN_IA64_EXPOSE_P2M
static struct page_info* p2m_pte_zero_page = NULL;
+/* This must called before dom0 p2m table allocation */
void __init
expose_p2m_init(void)
{
pte_t* pte;
+
+ /*
+ * Initialise our DOMID_P2M domain.
+ * This domain owns m2p table pages.
+ */
+ dom_p2m = alloc_domain(DOMID_P2M);
+ BUG_ON(dom_p2m == NULL);
+ dom_p2m->max_pages = ~0U;
pte = pte_alloc_one_kernel(NULL, 0);
BUG_ON(pte == NULL);
@@ -1393,13 +1406,8 @@ static int
static int
expose_p2m_page(struct domain* d, unsigned long mpaddr, struct page_info* page)
{
- // we can't get_page(page) here.
- // pte page is allocated form xen heap.(see pte_alloc_one_kernel().)
- // so that the page has NULL page owner and it's reference count
- // is useless.
- // see also mm_teardown_pte()'s page_get_owner() == NULL check.
- BUG_ON(page_get_owner(page) != NULL);
-
+ int ret = get_page(page, dom_p2m);
+ BUG_ON(ret != 1);
return __assign_domain_page(d, mpaddr, page_to_maddr(page),
ASSIGN_readonly);
}
@@ -1918,8 +1926,10 @@ void *pgtable_quicklist_alloc(void)
void *pgtable_quicklist_alloc(void)
{
void *p;
+
+ BUG_ON(dom_p2m == NULL);
if (!opt_p2m_xenheap) {
- struct page_info *page = alloc_domheap_page(NULL);
+ struct page_info *page = alloc_domheap_page(dom_p2m);
if (page == NULL)
return NULL;
p = page_to_virt(page);
@@ -1927,16 +1937,26 @@ void *pgtable_quicklist_alloc(void)
return p;
}
p = alloc_xenheap_pages(0);
- if (p)
+ if (p) {
clear_page(p);
+ /*
+ * This page should be read only. At this moment, the third
+ * argument doesn't make sense. It should be 1 when supported.
+ */
+ share_xen_page_with_guest(virt_to_page(p), dom_p2m, 0);
+ }
return p;
}
void pgtable_quicklist_free(void *pgtable_entry)
{
- if (!opt_p2m_xenheap)
- free_domheap_page(virt_to_page(pgtable_entry));
- else
+ struct page_info* page = virt_to_page(pgtable_entry);
+
+ BUG_ON(page_get_owner(page) != dom_p2m);
+ BUG_ON(page->count_info != (1 | PGC_allocated));
+
+ put_page(page);
+ if (opt_p2m_xenheap)
free_xenheap_page(pgtable_entry);
}
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