x86/mm/p2m: little fixes and tidying up

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>

6 files changed, 123 insertions, 121 deletions

diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
index 2e2dfbf18d..fca5caa21b 100644
--- a/xen/arch/x86/mm/p2m-pod.c
+++ b/xen/arch/x86/mm/p2m-pod.c
@@ -42,7 +42,6 @@
 #undef page_to_mfn
 #define page_to_mfn(_pg) _mfn(__page_to_mfn(_pg))
 
-#define SUPERPAGE_PAGES (1UL << 9)
 #define superpage_aligned(_x)  (((_x)&(SUPERPAGE_PAGES-1))==0)
 
 /*
@@ -688,8 +687,7 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn)
     }
 
     /* Try to remove the page, restoring old mapping if it fails. */
-    set_p2m_entry(p2m, gfn,
-                  _mfn(POPULATE_ON_DEMAND_MFN), 9,
+    set_p2m_entry(p2m, gfn, _mfn(0), 9,
                   p2m_populate_on_demand, p2m->default_access);
 
     /* Make none of the MFNs are used elsewhere... for example, mapped
@@ -801,8 +799,7 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count)
         }
 
         /* Try to remove the page, restoring old mapping if it fails. */
-        set_p2m_entry(p2m, gfns[i],
-                      _mfn(POPULATE_ON_DEMAND_MFN), 0,
+        set_p2m_entry(p2m, gfns[i], _mfn(0), 0,
                       p2m_populate_on_demand, p2m->default_access);
 
         /* See if the page was successfully unmapped.  (Allow one refcount
@@ -966,7 +963,7 @@ p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn,
          * set_p2m_entry() should automatically shatter the 1GB page into 
          * 512 2MB pages. The rest of 511 calls are unnecessary.
          */
-        set_p2m_entry(p2m, gfn_aligned, _mfn(POPULATE_ON_DEMAND_MFN), 9,
+        set_p2m_entry(p2m, gfn_aligned, _mfn(0), 9,
                       p2m_populate_on_demand, p2m->default_access);
         audit_p2m(p2m, 1);
         p2m_unlock(p2m);
@@ -1054,7 +1051,7 @@ remap_and_retry:
     /* Remap this 2-meg region in singleton chunks */
     gfn_aligned = (gfn>>order)<<order;
     for(i=0; i<(1<<order); i++)
-        set_p2m_entry(p2m, gfn_aligned+i, _mfn(POPULATE_ON_DEMAND_MFN), 0,
+        set_p2m_entry(p2m, gfn_aligned+i, _mfn(0), 0,
                       p2m_populate_on_demand, p2m->default_access);
     if ( tb_init_done )
     {
@@ -1114,7 +1111,7 @@ guest_physmap_mark_populate_on_demand(struct domain *d, unsigned long gfn,
     }
 
     /* Now, actually do the two-way mapping */
-    if ( !set_p2m_entry(p2m, gfn, _mfn(POPULATE_ON_DEMAND_MFN), order,
+    if ( !set_p2m_entry(p2m, gfn, _mfn(0), order,
                         p2m_populate_on_demand, p2m->default_access) )
         rc = -EINVAL;
     else
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index c664bf3c6f..229d79d02c 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -51,9 +51,6 @@
 #define P2M_BASE_FLAGS \
         (_PAGE_PRESENT | _PAGE_USER | _PAGE_DIRTY | _PAGE_ACCESSED)
 
-#define SUPERPAGE_PAGES (1UL << 9)
-#define superpage_aligned(_x)  (((_x)&(SUPERPAGE_PAGES-1))==0)
-
 static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t mfn)
 {
     unsigned long flags;
@@ -67,32 +64,31 @@ static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t mfn)
 #else
     flags = (t & 0x7UL) << 9;
 #endif
-#ifndef HAVE_GRANT_MAP_P2M
-    BUG_ON(p2m_is_grant(t));
+
+#ifndef __x86_64__
+    /* 32-bit builds don't support a lot of the p2m types */
+    BUG_ON(t > p2m_populate_on_demand);
 #endif
+
     switch(t)
     {
     case p2m_invalid:
+    case p2m_mmio_dm:
+    case p2m_populate_on_demand:
     default:
         return flags;
-    case p2m_ram_rw:
-    case p2m_grant_map_rw:
-        return flags | P2M_BASE_FLAGS | _PAGE_RW;
-    case p2m_ram_logdirty:
-        return flags | P2M_BASE_FLAGS;
     case p2m_ram_ro:
     case p2m_grant_map_ro:
-        return flags | P2M_BASE_FLAGS;
+    case p2m_ram_logdirty:
     case p2m_ram_shared:
         return flags | P2M_BASE_FLAGS;
-    case p2m_mmio_dm:
-        return flags;
+    case p2m_ram_rw:
+    case p2m_grant_map_rw:
+        return flags | P2M_BASE_FLAGS | _PAGE_RW;
     case p2m_mmio_direct:
         if ( !rangeset_contains_singleton(mmio_ro_ranges, mfn_x(mfn)) )
             flags |= _PAGE_RW;
         return flags | P2M_BASE_FLAGS | _PAGE_PCD;
-    case p2m_populate_on_demand:
-        return flags;
     }
 }
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 618aa132af..14cb2227c3 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -243,31 +243,30 @@ int p2m_alloc_table(struct p2m_domain *p2m)
                         p2m_invalid, p2m->default_access) )
         goto error;
 
-    if (p2m_is_nestedp2m(p2m))
-        goto nesteddone;
-
-    /* Copy all existing mappings from the page list and m2p */
-    spin_lock(&p2m->domain->page_alloc_lock);
-    page_list_for_each(page, &p2m->domain->page_list)
+    if ( !p2m_is_nestedp2m(p2m) )
     {
-        mfn = page_to_mfn(page);
-        gfn = get_gpfn_from_mfn(mfn_x(mfn));
-        /* Pages should not be shared that early */
-        ASSERT(gfn != SHARED_M2P_ENTRY);
-        page_count++;
-        if (
+        /* Copy all existing mappings from the page list and m2p */
+        spin_lock(&p2m->domain->page_alloc_lock);
+        page_list_for_each(page, &p2m->domain->page_list)
+        {
+            mfn = page_to_mfn(page);
+            gfn = get_gpfn_from_mfn(mfn_x(mfn));
+            /* Pages should not be shared that early */
+            ASSERT(gfn != SHARED_M2P_ENTRY);
+            page_count++;
+            if (
 #ifdef __x86_64__
-            (gfn != 0x5555555555555555L)
+                (gfn != 0x5555555555555555L)
 #else
-            (gfn != 0x55555555L)
+                (gfn != 0x55555555L)
 #endif
-             && gfn != INVALID_M2P_ENTRY
-            && !set_p2m_entry(p2m, gfn, mfn, 0, p2m_ram_rw, p2m->default_access) )
-            goto error_unlock;
+                && gfn != INVALID_M2P_ENTRY
+                && !set_p2m_entry(p2m, gfn, mfn, 0, p2m_ram_rw, p2m->default_access) )
+                goto error_unlock;
+        }
+        spin_unlock(&p2m->domain->page_alloc_lock);
     }
-    spin_unlock(&p2m->domain->page_alloc_lock);
 
- nesteddone:
     P2M_PRINTK("p2m table initialised (%u pages)\n", page_count);
     p2m_unlock(p2m);
     return 0;
@@ -693,7 +692,8 @@ int p2m_mem_paging_evict(struct p2m_domain *p2m, unsigned long gfn)
 
     /* Remove mapping from p2m table */
     p2m_lock(p2m);
-    set_p2m_entry(p2m, gfn, _mfn(PAGING_MFN), 0, p2m_ram_paged, p2m->default_access);
+    set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), 0, 
+                  p2m_ram_paged, p2m->default_access);
     audit_p2m(p2m, 1);
     p2m_unlock(p2m);
 
@@ -743,7 +743,8 @@ void p2m_mem_paging_populate(struct p2m_domain *p2m, unsigned long gfn)
     if ( p2mt == p2m_ram_paged )
     {
         p2m_lock(p2m);
-        set_p2m_entry(p2m, gfn, _mfn(PAGING_MFN), 0, p2m_ram_paging_in_start, p2m->default_access);
+        set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), 0, 
+                      p2m_ram_paging_in_start, p2m->default_access);
         audit_p2m(p2m, 1);
         p2m_unlock(p2m);
     }
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index cbf1da2835..14976083d7 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -47,10 +47,6 @@
  */
 #define phys_to_machine_mapping ((l1_pgentry_t *)RO_MPT_VIRT_START)
 
-#ifdef __x86_64__
-#define HAVE_GRANT_MAP_P2M
-#endif
-
 /*
  * The upper levels of the p2m pagetable always contain full rights; all 
  * variation in the access control bits is made in the level-1 PTEs.
@@ -78,20 +74,16 @@ typedef enum {
     p2m_mmio_direct = 5,        /* Read/write mapping of genuine MMIO area */
     p2m_populate_on_demand = 6, /* Place-holder for empty memory */
 
-    /* Note that these can only be used if HAVE_GRANT_MAP_P2M is
-       defined.  They get defined anyway so as to avoid lots of
-       #ifdef's everywhere else. */
-    p2m_grant_map_rw = 7,       /* Read/write grant mapping */
-    p2m_grant_map_ro = 8,       /* Read-only grant mapping */
-
-    /* Likewise, although these are defined in all builds, they can only
+    /* Although these are defined in all builds, they can only
      * be used in 64-bit builds */
+    p2m_grant_map_rw = 7,         /* Read/write grant mapping */
+    p2m_grant_map_ro = 8,         /* Read-only grant mapping */
     p2m_ram_paging_out = 9,       /* Memory that is being paged out */
     p2m_ram_paged = 10,           /* Memory that has been paged out */
     p2m_ram_paging_in = 11,       /* Memory that is being paged in */
     p2m_ram_paging_in_start = 12, /* Memory that is being paged in */
     p2m_ram_shared = 13,          /* Shared or sharable memory */
-    p2m_ram_broken  =14,          /* Broken page, access cause domain crash */
+    p2m_ram_broken = 14,          /* Broken page, access cause domain crash */
 } p2m_type_t;
 
 /*
@@ -170,6 +162,9 @@ typedef enum {
  * reinit the type correctly after fault */
 #define P2M_SHARABLE_TYPES (p2m_to_mask(p2m_ram_rw))
 #define P2M_SHARED_TYPES   (p2m_to_mask(p2m_ram_shared))
+
+/* Broken type: the frame backing this pfn has failed in hardware
+ * and must not be touched. */
 #define P2M_BROKEN_TYPES (p2m_to_mask(p2m_ram_broken))
 
 /* Useful predicates */
@@ -190,12 +185,7 @@ typedef enum {
 #define p2m_is_shared(_t)   (p2m_to_mask(_t) & P2M_SHARED_TYPES)
 #define p2m_is_broken(_t)   (p2m_to_mask(_t) & P2M_BROKEN_TYPES)
 
-/* Populate-on-demand */
-#define POPULATE_ON_DEMAND_MFN  (1<<9)
-#define POD_PAGE_ORDER 9
-
-#define PAGING_MFN  INVALID_MFN
-
+/* Per-p2m-table state */
 struct p2m_domain {
     /* Lock that protects updates to the p2m */
     spinlock_t         lock;
@@ -298,10 +288,6 @@ struct p2m_domain *p2m_get_p2m(struct vcpu *v);
 
 #define p2m_get_pagetable(p2m)  ((p2m)->phys_table)
 
-/* Flushes specified p2m table */
-void p2m_flush(struct vcpu *v, struct p2m_domain *p2m);
-/* Flushes all nested p2m tables */
-void p2m_flush_nestedp2m(struct domain *d);
 
 /*
  * The P2M lock.  This protects all updates to the p2m table.
@@ -376,23 +362,6 @@ void p2m_flush_nestedp2m(struct domain *d);
         spin_unlock(&(_domain)->arch.nested_p2m_lock);                 \
     } while (0)
 
-/* Extract the type from the PTE flags that store it */
-static inline p2m_type_t p2m_flags_to_type(unsigned long flags)
-{
-    /* Type is stored in the "available" bits */
-#ifdef __x86_64__
-    /* For AMD IOMMUs we need to use type 0 for plain RAM, but we need
-     * to make sure that an entirely empty PTE doesn't have RAM type */
-    if ( flags == 0 ) 
-        return p2m_invalid;
-    /* AMD IOMMUs use bits 9-11 to encode next io page level and bits
-     * 59-62 for iommu flags so we can't use them to store p2m type info. */
-    return (flags >> 12) & 0x7f;
-#else
-    return (flags >> 9) & 0x7;
-#endif
-}
-
 /* Read the current domain's p2m table.  Do not populate PoD pages. */
 static inline mfn_t gfn_to_mfn_type_current(struct p2m_domain *p2m,
                                             unsigned long gfn, p2m_type_t *t,
@@ -508,38 +477,6 @@ int p2m_alloc_table(struct p2m_domain *p2m);
 void p2m_teardown(struct p2m_domain *p2m);
 void p2m_final_teardown(struct domain *d);
 
-/* Dump PoD information about the domain */
-void p2m_pod_dump_data(struct p2m_domain *p2m);
-
-/* Move all pages from the populate-on-demand cache to the domain page_list
- * (usually in preparation for domain destruction) */
-void p2m_pod_empty_cache(struct domain *d);
-
-/* Set populate-on-demand cache size so that the total memory allocated to a
- * domain matches target */
-int p2m_pod_set_mem_target(struct domain *d, unsigned long target);
-
-/* Call when decreasing memory reservation to handle PoD entries properly.
- * Will return '1' if all entries were handled and nothing more need be done.*/
-int
-p2m_pod_decrease_reservation(struct domain *d,
-                             xen_pfn_t gpfn,
-                             unsigned int order);
-
-/* Called by p2m code when demand-populating a PoD page */
-int
-p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn,
-                        unsigned int order,
-                        p2m_query_t q);
-
-/* Scan pod cache when offline/broken page triggered */
-int
-p2m_pod_offline_or_broken_hit(struct page_info *p);
-
-/* Replace pod cache when offline/broken page triggered */
-void
-p2m_pod_offline_or_broken_replace(struct page_info *p);
-
 /* Add a page to a domain's p2m table */
 int guest_physmap_add_entry(struct p2m_domain *p2m, unsigned long gfn,
                             unsigned long mfn, unsigned int page_order, 
@@ -553,10 +490,7 @@ void guest_physmap_remove_entry(struct p2m_domain *p2m, unsigned long gfn,
 int guest_physmap_mark_populate_on_demand(struct domain *d, unsigned long gfn,
                                           unsigned int order);
 
-/* Untyped version for RAM only, for compatibility 
- *
- * Return 0 for success
- */
+/* Untyped version for RAM only, for compatibility */
 static inline int guest_physmap_add_page(struct domain *d,
                                          unsigned long gfn,
                                          unsigned long mfn,
@@ -584,8 +518,46 @@ p2m_type_t p2m_change_type(struct p2m_domain *p2m, unsigned long gfn,
 int set_mmio_p2m_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn);
 int clear_mmio_p2m_entry(struct p2m_domain *p2m, unsigned long gfn);
 
-void nestedp2m_write_p2m_entry(struct p2m_domain *p2m, unsigned long gfn,
-    l1_pgentry_t *p, mfn_t table_mfn, l1_pgentry_t new, unsigned int level);
+
+/* 
+ * Populate-on-demand
+ */
+
+/* Dump PoD information about the domain */
+void p2m_pod_dump_data(struct p2m_domain *p2m);
+
+/* Move all pages from the populate-on-demand cache to the domain page_list
+ * (usually in preparation for domain destruction) */
+void p2m_pod_empty_cache(struct domain *d);
+
+/* Set populate-on-demand cache size so that the total memory allocated to a
+ * domain matches target */
+int p2m_pod_set_mem_target(struct domain *d, unsigned long target);
+
+/* Call when decreasing memory reservation to handle PoD entries properly.
+ * Will return '1' if all entries were handled and nothing more need be done.*/
+int
+p2m_pod_decrease_reservation(struct domain *d,
+                             xen_pfn_t gpfn,
+                             unsigned int order);
+
+/* Called by p2m code when demand-populating a PoD page */
+int
+p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn,
+                        unsigned int order,
+                        p2m_query_t q);
+
+/* Scan pod cache when offline/broken page triggered */
+int
+p2m_pod_offline_or_broken_hit(struct page_info *p);
+
+/* Replace pod cache when offline/broken page triggered */
+void
+p2m_pod_offline_or_broken_replace(struct page_info *p);
+
+/*
+ * Paging to disk and page-sharing
+ */
 
 #ifdef __x86_64__
 /* Modify p2m table for shared gfn */
@@ -680,6 +652,40 @@ extern void audit_p2m(struct p2m_domain *p2m, int strict_m2p);
 #define P2M_DEBUG(_f, _a...) do { (void)(_f); } while(0)
 #endif
 
+
+/*
+ * Functions specific to the p2m-pt implementation
+ */
+
+/* Extract the type from the PTE flags that store it */
+static inline p2m_type_t p2m_flags_to_type(unsigned long flags)
+{
+    /* Type is stored in the "available" bits */
+#ifdef __x86_64__
+    /* For AMD IOMMUs we need to use type 0 for plain RAM, but we need
+     * to make sure that an entirely empty PTE doesn't have RAM type */
+    if ( flags == 0 ) 
+        return p2m_invalid;
+    /* AMD IOMMUs use bits 9-11 to encode next io page level and bits
+     * 59-62 for iommu flags so we can't use them to store p2m type info. */
+    return (flags >> 12) & 0x7f;
+#else
+    return (flags >> 9) & 0x7;
+#endif
+}
+
+/*
+ * Nested p2m: shadow p2m tables used for nexted HVM virtualization 
+ */
+
+/* Flushes specified p2m table */
+void p2m_flush(struct vcpu *v, struct p2m_domain *p2m);
+/* Flushes all nested p2m tables */
+void p2m_flush_nestedp2m(struct domain *d);
+
+void nestedp2m_write_p2m_entry(struct p2m_domain *p2m, unsigned long gfn,
+    l1_pgentry_t *p, mfn_t table_mfn, l1_pgentry_t new, unsigned int level);
+
 #endif /* _XEN_P2M_H */
 
 /*
diff --git a/xen/include/asm-x86/x86_32/page.h b/xen/include/asm-x86/x86_32/page.h
index 122463dc4d..8dd4310b27 100644
--- a/xen/include/asm-x86/x86_32/page.h
+++ b/xen/include/asm-x86/x86_32/page.h
@@ -15,6 +15,7 @@
 #define L3_PAGETABLE_ENTRIES    4
 #define ROOT_PAGETABLE_ENTRIES  L3_PAGETABLE_ENTRIES
 #define SUPERPAGE_ORDER         PAGETABLE_ORDER
+#define SUPERPAGE_PAGES         (1<<SUPERPAGE_ORDER)
 
 /*
  * Architecturally, physical addresses may be up to 52 bits. However, the
diff --git a/xen/include/asm-x86/x86_64/page.h b/xen/include/asm-x86/x86_64/page.h
index 38edb91bf3..d146e992e8 100644
--- a/xen/include/asm-x86/x86_64/page.h
+++ b/xen/include/asm-x86/x86_64/page.h
@@ -17,6 +17,7 @@
 #define L4_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
 #define ROOT_PAGETABLE_ENTRIES  L4_PAGETABLE_ENTRIES
 #define SUPERPAGE_ORDER         PAGETABLE_ORDER
+#define SUPERPAGE_PAGES         (1<<SUPERPAGE_ORDER)
 
 #define __PAGE_OFFSET           DIRECTMAP_VIRT_START
 #define __XEN_VIRT_START        XEN_VIRT_START