mm: add 'is_special_page' inline function...

... to cover xenheap and PGC_extra pages.

PGC_extra pages are intended to hold data structures that are associated
with a domain and may be mapped by that domain. They should not be treated
as 'normal' guest pages (i.e. RAM or page tables). Hence, in many cases
where code currently tests is_xen_heap_page() it should also check for
the PGC_extra bit in 'count_info'.

This patch therefore defines is_special_page() to cover both cases and
converts tests of is_xen_heap_page() (or open coded tests of PGC_xen_heap)
to is_special_page() where the page is assigned to a domain.

Signed-off-by: Paul Durrant <paul@xen.org>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <julien@xen.org>

diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index ed86762fa6edb2abff9324cbe4e56e7629844b05..add70126b9a119a59b181d42a19efb5508ad42cd 100644 (file)
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -394,7 +394,7 @@ long arch_do_domctl(
             page = get_page_from_gfn(d, gfn, &t, P2M_ALLOC);
 
             if ( unlikely(!page) ||
-                 unlikely(is_xen_heap_page(page)) )
+                 unlikely(is_special_page(page)) )
             {
                 if ( unlikely(p2m_is_broken(t)) )
                     type = XEN_DOMCTL_PFINFO_BROKEN;

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 62507ca651590fc0fba4dff5dbe5b9e94542d80c..2fac67ad57010bb76b74b1be0b129e6cc97f6c0a 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -1014,7 +1014,7 @@ get_page_from_l1e(
         unsigned long cacheattr = pte_flags_to_cacheattr(l1f);
         int err;
 
-        if ( is_xen_heap_page(page) )
+        if ( is_special_page(page) )
         {
             if ( write )
                 put_page_type(page);
@@ -2447,7 +2447,7 @@ static int cleanup_page_mappings(struct page_info *page)
     {
         page->count_info &= ~PGC_cacheattr_mask;
 
-        BUG_ON(is_xen_heap_page(page));
+        BUG_ON(is_special_page(page));
 
         rc = update_xen_mappings(mfn, 0);
     }
@@ -2477,7 +2477,7 @@ static int cleanup_page_mappings(struct page_info *page)
                 rc = rc2;
         }
 
-        if ( likely(!is_xen_heap_page(page)) )
+        if ( likely(!is_special_page(page)) )
         {
             ASSERT((page->u.inuse.type_info &
                     (PGT_type_mask | PGT_count_mask)) == PGT_writable_page);
@@ -4216,8 +4216,7 @@ int steal_page(
     if ( !(owner = page_get_owner_and_reference(page)) )
         goto fail;
 
-    if ( owner != d || is_xen_heap_page(page) ||
-         (page->count_info & PGC_extra) )
+    if ( owner != d || is_special_page(page) )
         goto fail_put;
 
     /*
@@ -4580,8 +4579,8 @@ int xenmem_add_to_physmap_one(
     prev_mfn = get_gfn(d, gfn_x(gpfn), &p2mt);
     if ( mfn_valid(prev_mfn) )
     {
-        if ( is_xen_heap_mfn(prev_mfn) )
-            /* Xen heap frames are simply unhooked from this phys slot. */
+        if ( is_special_page(mfn_to_page(prev_mfn)) )
+            /* Special pages are simply unhooked from this phys slot. */
             rc = guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */

diff --git a/xen/arch/x86/mm/altp2m.c b/xen/arch/x86/mm/altp2m.c
index 50768f2547754d9b2c1411ccf2124087769af2d6..c091b03ea3e07f083cc6b6a7a016d7a2c49a1c96 100644 (file)
--- a/xen/arch/x86/mm/altp2m.c
+++ b/xen/arch/x86/mm/altp2m.c
@@ -77,7 +77,7 @@ int altp2m_vcpu_enable_ve(struct vcpu *v, gfn_t gfn)
      * pageable() predicate for this, due to it having the same properties
      * that we want.
      */
-    if ( !p2m_is_pageable(p2mt) || is_xen_heap_page(pg) )
+    if ( !p2m_is_pageable(p2mt) || is_special_page(pg) )
     {
         rc = -EINVAL;
         goto err;

diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 3835bc928f3e998d17d59aa20198049533b2c398..f49f27a3efc669216d0ad8b0ca3ef51c5b38f359 100644 (file)
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -840,9 +840,8 @@ static int nominate_page(struct domain *d, gfn_t gfn,
     if ( !p2m_is_sharable(p2mt) )
         goto out;
 
-    /* Skip xen heap pages */
     page = mfn_to_page(mfn);
-    if ( !page || is_xen_heap_page(page) )
+    if ( !page || is_special_page(page) )
         goto out;
 
     /* Check if there are mem_access/remapped altp2m entries for this page */

diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
index 2a7b8c117b8a93e766820b0eaed2fbba0c65b960..36bc471e7fa2a35bf31239366b935480fa7d1563 100644 (file)
--- a/xen/arch/x86/mm/p2m-pod.c
+++ b/xen/arch/x86/mm/p2m-pod.c
@@ -749,8 +749,9 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, gfn_t gfn)
 
         n = 1UL << min(cur_order, SUPERPAGE_ORDER + 0U);
         for ( k = 0, page = mfn_to_page(mfn); k < n; ++k, ++page )
-            if ( !(page->count_info & PGC_allocated) ||
-                 (page->count_info & (PGC_page_table | PGC_xen_heap)) ||
+            if ( is_special_page(page) ||
+                 !(page->count_info & PGC_allocated) ||
+                 (page->count_info & PGC_page_table) ||
                  (page->count_info & PGC_count_mask) > max_ref )
                 goto out;
     }
@@ -883,11 +884,12 @@ p2m_pod_zero_check(struct p2m_domain *p2m, const gfn_t *gfns, unsigned int count
         pg = mfn_to_page(mfns[i]);
 
         /*
-         * If this is ram, and not a pagetable or from the xen heap, and
+         * If this is ram, and not a pagetable or a special page, and
          * probably not mapped elsewhere, map it; otherwise, skip.
          */
-        if ( p2m_is_ram(types[i]) && (pg->count_info & PGC_allocated) &&
-             !(pg->count_info & (PGC_page_table | PGC_xen_heap)) &&
+        if ( !is_special_page(pg) && p2m_is_ram(types[i]) &&
+             (pg->count_info & PGC_allocated) &&
+             !(pg->count_info & PGC_page_table) &&
              ((pg->count_info & PGC_count_mask) <= max_ref) )
             map[i] = map_domain_page(mfns[i]);
         else

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 9f51370327fc25b47595c058c750d27f9bd403d2..d93c418bcf045334b165efcd7948c3f8ce810a9b 100644 (file)
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2983,8 +2983,8 @@ int p2m_add_foreign(struct domain *tdom, unsigned long fgfn,
     prev_mfn = get_gfn(tdom, gpfn, &p2mt_prev);
     if ( mfn_valid(prev_mfn) )
     {
-        if ( is_xen_heap_mfn(prev_mfn) )
-            /* Xen heap frames are simply unhooked from this phys slot */
+        if ( is_special_page(mfn_to_page(prev_mfn)) )
+            /* Special pages are simply unhooked from this phys slot */
             rc = guest_physmap_remove_page(tdom, _gfn(gpfn), prev_mfn, 0);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 121ddf125556c5050c7c5e0386bfd5eaab9f2328..75dd414a6ee6d25a7d01240cd3f82f934f6fcaa8 100644 (file)
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -2087,19 +2087,22 @@ static int sh_remove_all_mappings(struct domain *d, mfn_t gmfn, gfn_t gfn)
          * The qemu helper process has an untyped mapping of this dom's RAM
          * and the HVM restore program takes another.
          * Also allow one typed refcount for
-         * - Xen heap pages, to match share_xen_page_with_guest(),
-         * - ioreq server pages, to match prepare_ring_for_helper().
+         * - special pages, which are explicitly referenced and mapped by
+         *   Xen.
+         * - ioreq server pages, which may be special pages or normal
+         *   guest pages with an extra reference taken by
+         *   prepare_ring_for_helper().
          */
         if ( !(shadow_mode_external(d)
                && (page->count_info & PGC_count_mask) <= 3
                && ((page->u.inuse.type_info & PGT_count_mask)
-                   == (is_xen_heap_page(page) ||
+                   == (is_special_page(page) ||
                        (is_hvm_domain(d) && is_ioreq_server_page(d, page))))) )
             printk(XENLOG_G_ERR "can't find all mappings of mfn %"PRI_mfn
-                   " (gfn %"PRI_gfn"): c=%lx t=%lx x=%d i=%d\n",
+                   " (gfn %"PRI_gfn"): c=%lx t=%lx s=%d i=%d\n",
                    mfn_x(gmfn), gfn_x(gfn),
                    page->count_info, page->u.inuse.type_info,
-                   !!is_xen_heap_page(page),
+                   is_special_page(page),
                    (is_hvm_domain(d) && is_ioreq_server_page(d, page)));
     }
 

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index b6afc0fba47f5851b891405ea379adcf1d4e82fb..f6b162874262da1c9d53a870c7f13f219ecdc598 100644 (file)
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -559,7 +559,8 @@ _sh_propagate(struct vcpu *v,
      * caching attributes in the shadows to match what was asked for.
      */
     if ( (level == 1) && is_hvm_domain(d) &&
-         !is_xen_heap_mfn(target_mfn) )
+         (!mfn_valid(target_mfn) ||
+          !is_special_page(mfn_to_page(target_mfn))) )
     {
         int type;
 

diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index ce85a710dd4dbb9205c0c672b4bfd8572097556e..102c3cd20312df3c6ef2b41fb2bc60f736c01a8b 100644 (file)
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -189,7 +189,7 @@ static void update_pagetable_mac(vmac_ctx_t *ctx)
 
         if ( !mfn_valid(_mfn(mfn)) )
             continue;
-        if ( is_page_in_use(page) && !is_xen_heap_page(page) )
+        if ( is_page_in_use(page) && !is_special_page(page) )
         {
             if ( page->count_info & PGC_page_table )
             {
@@ -289,7 +289,7 @@ static void tboot_gen_xenheap_integrity(const uint8_t key[TB_KEY_SIZE],
                               + 3 * PAGE_SIZE)) )
             continue; /* skip tboot and its page tables */
 
-        if ( is_page_in_use(page) && is_xen_heap_page(page) )
+        if ( is_page_in_use(page) && is_special_page(page) )
         {
             void *pg;
 

diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index a163c201e24ad84ea7002626c0c55f3fac8c0711..9b62087be147021a4bb35358af429f89db598688 100644 (file)
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -285,6 +285,11 @@ extern struct domain *dom_cow;
 
 #include <asm/mm.h>
 
+static inline bool is_special_page(const struct page_info *page)
+{
+    return is_xen_heap_page(page) || (page->count_info & PGC_extra);
+}
+
 #ifndef page_list_entry
 struct page_list_head
 {