[Xen-devel] [PATCH v4 24/31] x86/mm: move and add pv_ prefix to create_pae_xen_mappings

[Wei Liu <wei.liu2@xxxxxxxxxx>]

And export it via a local header because it is going to be used by
several PV specific files.

Take the chance to change its return type to bool.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 xen/arch/x86/mm.c    | 46 ++++------------------------------------------
 xen/arch/x86/pv/mm.c | 40 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/x86/pv/mm.h |  6 ++++++
 3 files changed, 50 insertions(+), 42 deletions(-)
 create mode 100644 xen/arch/x86/pv/mm.h

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index fb6485500f..5bfdfabc5e 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -127,6 +127,8 @@
 #include <asm/pv/grant_table.h>
 #include <asm/pv/mm.h>
 
+#include "pv/mm.h"
+
 /* Mapping of the fixmap space needed early. */
 l1_pgentry_t __section(".bss.page_aligned") __aligned(PAGE_SIZE)
     l1_fixmap[L1_PAGETABLE_ENTRIES];
@@ -1219,46 +1221,6 @@ static int alloc_l1_table(struct page_info *page)
     return ret;
 }
 
-static int create_pae_xen_mappings(struct domain *d, l3_pgentry_t *pl3e)
-{
-    struct page_info *page;
-    l3_pgentry_t     l3e3;
-
-    if ( !is_pv_32bit_domain(d) )
-        return 1;
-
-    pl3e = (l3_pgentry_t *)((unsigned long)pl3e & PAGE_MASK);
-
-    /* 3rd L3 slot contains L2 with Xen-private mappings. It *must* exist. */
-    l3e3 = pl3e[3];
-    if ( !(l3e_get_flags(l3e3) & _PAGE_PRESENT) )
-    {
-        gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is empty\n");
-        return 0;
-    }
-
-    /*
-     * The Xen-private mappings include linear mappings. The L2 thus cannot
-     * be shared by multiple L3 tables. The test here is adequate because:
-     *  1. Cannot appear in slots != 3 because get_page_type() checks the
-     *     PGT_pae_xen_l2 flag, which is asserted iff the L2 appears in slot 3
-     *  2. Cannot appear in another page table's L3:
-     *     a. alloc_l3_table() calls this function and this check will fail
-     *     b. mod_l3_entry() disallows updates to slot 3 in an existing table
-     */
-    page = l3e_get_page(l3e3);
-    BUG_ON(page->u.inuse.type_info & PGT_pinned);
-    BUG_ON((page->u.inuse.type_info & PGT_count_mask) == 0);
-    BUG_ON(!(page->u.inuse.type_info & PGT_pae_xen_l2));
-    if ( (page->u.inuse.type_info & PGT_count_mask) != 1 )
-    {
-        gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is shared\n");
-        return 0;
-    }
-
-    return 1;
-}
-
 static int alloc_l2_table(struct page_info *page, unsigned long type,
                           int preemptible)
 {
@@ -1363,7 +1325,7 @@ static int alloc_l3_table(struct page_info *page)
         adjust_guest_l3e(pl3e[i], d);
     }
 
-    if ( rc >= 0 && !create_pae_xen_mappings(d, pl3e) )
+    if ( rc >= 0 && !pv_create_pae_xen_mappings(d, pl3e) )
         rc = -EINVAL;
     if ( rc < 0 && rc != -ERESTART && rc != -EINTR )
     {
@@ -1835,7 +1797,7 @@ static int mod_l3_entry(l3_pgentry_t *pl3e,
     }
 
     if ( likely(rc == 0) )
-        if ( !create_pae_xen_mappings(d, pl3e) )
+        if ( !pv_create_pae_xen_mappings(d, pl3e) )
             BUG();
 
     put_page_from_l3e(ol3e, pfn, 0, 1);
diff --git a/xen/arch/x86/pv/mm.c b/xen/arch/x86/pv/mm.c
index 0f4303cef2..46e1fcf4e5 100644
--- a/xen/arch/x86/pv/mm.c
+++ b/xen/arch/x86/pv/mm.c
@@ -211,6 +211,46 @@ bool pv_update_intpte(intpte_t *p, intpte_t old, intpte_t 
new,
     return rv;
 }
 
+bool pv_create_pae_xen_mappings(struct domain *d, l3_pgentry_t *pl3e)
+{
+    struct page_info *page;
+    l3_pgentry_t     l3e3;
+
+    if ( !is_pv_32bit_domain(d) )
+        return true;
+
+    pl3e = (l3_pgentry_t *)((unsigned long)pl3e & PAGE_MASK);
+
+    /* 3rd L3 slot contains L2 with Xen-private mappings. It *must* exist. */
+    l3e3 = pl3e[3];
+    if ( !(l3e_get_flags(l3e3) & _PAGE_PRESENT) )
+    {
+        gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is empty\n");
+        return false;
+    }
+
+    /*
+     * The Xen-private mappings include linear mappings. The L2 thus cannot
+     * be shared by multiple L3 tables. The test here is adequate because:
+     *  1. Cannot appear in slots != 3 because get_page_type() checks the
+     *     PGT_pae_xen_l2 flag, which is asserted iff the L2 appears in slot 3
+     *  2. Cannot appear in another page table's L3:
+     *     a. alloc_l3_table() calls this function and this check will fail
+     *     b. mod_l3_entry() disallows updates to slot 3 in an existing table
+     */
+    page = l3e_get_page(l3e3);
+    BUG_ON(page->u.inuse.type_info & PGT_pinned);
+    BUG_ON((page->u.inuse.type_info & PGT_count_mask) == 0);
+    BUG_ON(!(page->u.inuse.type_info & PGT_pae_xen_l2));
+    if ( (page->u.inuse.type_info & PGT_count_mask) != 1 )
+    {
+        gdprintk(XENLOG_WARNING, "PAE L3 3rd slot is shared\n");
+        return false;
+    }
+
+    return true;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/pv/mm.h b/xen/arch/x86/pv/mm.h
new file mode 100644
index 0000000000..bafc2b6116
--- /dev/null
+++ b/xen/arch/x86/pv/mm.h
@@ -0,0 +1,6 @@
+#ifndef __PV_MM_H__
+#define __PV_MM_H__
+
+bool pv_create_pae_xen_mappings(struct domain *d, l3_pgentry_t *pl3e);
+
+#endif /* __PV_MM_H__ */
-- 
2.11.0


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