From: Keir Fraser <keir.fraser@citrix.com>
Date: Tue, 15 Jun 2010 12:20:43 +0000 (+0100)
Subject: x86: put_superpage() must also work for !opt_allow_superpage
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~11924
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22?a=commitdiff_plain;h=622c5d9ee4f9443a9632dc014f1fda27303aa77e;p=xen.git

x86: put_superpage() must also work for !opt_allow_superpage

This is because the P2M table, when placed at a kernel specified
location, gets populated with large pages, which the domain must have
a way to unmap/recycle.

Additionally when allowing Dom0 to use superpages, they ought to be
tracked accordingly in the superpage frame table.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
---

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index 166509f2e2..3995897e5b 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -914,6 +914,8 @@ int __init construct_dom0(
                 {
                     *l2tab = l2e_from_page(page,
                                            L1_PROT|_PAGE_DIRTY|_PAGE_PSE);
+                    if ( opt_allow_superpage )
+                        get_superpage(page_to_mfn(page), d);
                     va += 1UL << L2_PAGETABLE_SHIFT;
                     continue;
                 }
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 6256e0d027..dcfb7a682a 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -155,7 +155,9 @@ unsigned long __read_mostly pdx_group_valid[BITS_TO_LONGS(
 int opt_allow_superpage;
 boolean_param("allowsuperpage", opt_allow_superpage);
 
+#ifdef __i386__
 static int get_superpage(unsigned long mfn, struct domain *d);
+#endif
 static void put_superpage(unsigned long mfn);
 
 #define l1_disallow_mask(d)                                     \
@@ -2568,7 +2570,7 @@ void clear_superpage_mark(struct page_info *page)
 
 }
 
-static int get_superpage(unsigned long mfn, struct domain *d)
+int get_superpage(unsigned long mfn, struct domain *d)
 {
     struct spage_info *spage;
     unsigned long x, nx, y;
@@ -2611,7 +2613,11 @@ static void put_superpage(unsigned long mfn)
     unsigned long x, nx, y;
     unsigned long do_pages = 0;
 
-    ASSERT(opt_allow_superpage);
+    if ( !opt_allow_superpage )
+    {
+        put_spage_pages(mfn_to_page(mfn));
+        return;
+    }
 
     spage = mfn_to_spage(mfn);
     y = spage->type_info;
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index f1d6c8dc1c..2005b7be95 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -281,6 +281,7 @@ extern void share_xen_page_with_privileged_guests(
 #define frame_table ((struct page_info *)FRAMETABLE_VIRT_START)
 #ifdef __x86_64__
 #define spage_table ((struct spage_info *)SPAGETABLE_VIRT_START)
+int get_superpage(unsigned long mfn, struct domain *d);
 #endif
 extern unsigned long max_page;
 extern unsigned long total_pages;