diff mbox

[v3,extra,10/11] x86/mm: move {get, put}_page_from_l{2, 3, 4}e

Message ID 20170730154335.24313-11-wei.liu2@citrix.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wei Liu July 30, 2017, 3:43 p.m. UTC
They are only used by PV code.

Fix coding style issues while moving. Move declarations to PV specific
header file.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/mm.c           | 253 --------------------------------------------
 xen/arch/x86/pv/mm.c        | 246 ++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/mm.h    |  10 --
 xen/include/asm-x86/pv/mm.h |  29 +++++
 4 files changed, 275 insertions(+), 263 deletions(-)
diff mbox

Patch

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 40fb761d08..ade3ed2c48 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -511,72 +511,6 @@  int get_page_and_type_from_mfn(mfn_t mfn, unsigned long type, struct domain *d,
     return rc;
 }
 
-static void put_data_page(
-    struct page_info *page, int writeable)
-{
-    if ( writeable )
-        put_page_and_type(page);
-    else
-        put_page(page);
-}
-
-/*
- * We allow root tables to map each other (a.k.a. linear page tables). It
- * needs some special care with reference counts and access permissions:
- *  1. The mapping entry must be read-only, or the guest may get write access
- *     to its own PTEs.
- *  2. We must only bump the reference counts for an *already validated*
- *     L2 table, or we can end up in a deadlock in get_page_type() by waiting
- *     on a validation that is required to complete that validation.
- *  3. We only need to increment the reference counts for the mapped page
- *     frame if it is mapped by a different root table. This is sufficient and
- *     also necessary to allow validation of a root table mapping itself.
- */
-#define define_get_linear_pagetable(level)                                  \
-static int                                                                  \
-get_##level##_linear_pagetable(                                             \
-    level##_pgentry_t pde, unsigned long pde_pfn, struct domain *d)         \
-{                                                                           \
-    unsigned long x, y;                                                     \
-    struct page_info *page;                                                 \
-    unsigned long pfn;                                                      \
-                                                                            \
-    if ( (level##e_get_flags(pde) & _PAGE_RW) )                             \
-    {                                                                       \
-        gdprintk(XENLOG_WARNING,                                            \
-                 "Attempt to create linear p.t. with write perms\n");       \
-        return 0;                                                           \
-    }                                                                       \
-                                                                            \
-    if ( (pfn = level##e_get_pfn(pde)) != pde_pfn )                         \
-    {                                                                       \
-        /* Make sure the mapped frame belongs to the correct domain. */     \
-        if ( unlikely(!get_page_from_mfn(_mfn(pfn), d)) )                   \
-            return 0;                                                       \
-                                                                            \
-        /*                                                                  \
-         * Ensure that the mapped frame is an already-validated page table. \
-         * If so, atomically increment the count (checking for overflow).   \
-         */                                                                 \
-        page = mfn_to_page(pfn);                                            \
-        y = page->u.inuse.type_info;                                        \
-        do {                                                                \
-            x = y;                                                          \
-            if ( unlikely((x & PGT_count_mask) == PGT_count_mask) ||        \
-                 unlikely((x & (PGT_type_mask|PGT_validated)) !=            \
-                          (PGT_##level##_page_table|PGT_validated)) )       \
-            {                                                               \
-                put_page(page);                                             \
-                return 0;                                                   \
-            }                                                               \
-        }                                                                   \
-        while ( (y = cmpxchg(&page->u.inuse.type_info, x, x + 1)) != x );   \
-    }                                                                       \
-                                                                            \
-    return 1;                                                               \
-}
-
-
 bool is_iomem_page(mfn_t mfn)
 {
     struct page_info *page;
@@ -866,108 +800,6 @@  get_page_from_l1e(
 }
 
 
-/* NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'. */
-/*
- * get_page_from_l2e returns:
- *   1 => page not present
- *   0 => success
- *  <0 => error code
- */
-define_get_linear_pagetable(l2);
-int
-get_page_from_l2e(
-    l2_pgentry_t l2e, unsigned long pfn, struct domain *d)
-{
-    unsigned long mfn = l2e_get_pfn(l2e);
-    int rc;
-
-    if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
-        return 1;
-
-    if ( unlikely((l2e_get_flags(l2e) & L2_DISALLOW_MASK)) )
-    {
-        gdprintk(XENLOG_WARNING, "Bad L2 flags %x\n",
-                 l2e_get_flags(l2e) & L2_DISALLOW_MASK);
-        return -EINVAL;
-    }
-
-    if ( !(l2e_get_flags(l2e) & _PAGE_PSE) )
-    {
-        rc = get_page_and_type_from_mfn(_mfn(mfn), PGT_l1_page_table, d, 0,
-                                        false);
-        if ( unlikely(rc == -EINVAL) && get_l2_linear_pagetable(l2e, pfn, d) )
-            rc = 0;
-        return rc;
-    }
-
-    return -EINVAL;
-}
-
-
-/*
- * get_page_from_l3e returns:
- *   1 => page not present
- *   0 => success
- *  <0 => error code
- */
-define_get_linear_pagetable(l3);
-int
-get_page_from_l3e(
-    l3_pgentry_t l3e, unsigned long pfn, struct domain *d, int partial)
-{
-    int rc;
-
-    if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
-        return 1;
-
-    if ( unlikely((l3e_get_flags(l3e) & l3_disallow_mask(d))) )
-    {
-        gdprintk(XENLOG_WARNING, "Bad L3 flags %x\n",
-                 l3e_get_flags(l3e) & l3_disallow_mask(d));
-        return -EINVAL;
-    }
-
-    rc = get_page_and_type_from_mfn(_mfn(l3e_get_pfn(l3e)), PGT_l2_page_table,
-                                    d, partial, true);
-    if ( unlikely(rc == -EINVAL) &&
-         !is_pv_32bit_domain(d) &&
-         get_l3_linear_pagetable(l3e, pfn, d) )
-        rc = 0;
-
-    return rc;
-}
-
-/*
- * get_page_from_l4e returns:
- *   1 => page not present
- *   0 => success
- *  <0 => error code
- */
-define_get_linear_pagetable(l4);
-int
-get_page_from_l4e(
-    l4_pgentry_t l4e, unsigned long pfn, struct domain *d, int partial)
-{
-    int rc;
-
-    if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) )
-        return 1;
-
-    if ( unlikely((l4e_get_flags(l4e) & L4_DISALLOW_MASK)) )
-    {
-        gdprintk(XENLOG_WARNING, "Bad L4 flags %x\n",
-                 l4e_get_flags(l4e) & L4_DISALLOW_MASK);
-        return -EINVAL;
-    }
-
-    rc = get_page_and_type_from_mfn(_mfn(l4e_get_pfn(l4e)), PGT_l3_page_table,
-                                    d, partial, true);
-    if ( unlikely(rc == -EINVAL) && get_l4_linear_pagetable(l4e, pfn, d) )
-        rc = 0;
-
-    return rc;
-}
-
 void put_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner)
 {
     unsigned long     pfn = l1e_get_pfn(l1e);
@@ -1028,91 +860,6 @@  void put_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner)
 }
 
 
-/*
- * NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'.
- * Note also that this automatically deals correctly with linear p.t.'s.
- */
-int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn)
-{
-    if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) || (l2e_get_pfn(l2e) == pfn) )
-        return 1;
-
-    if ( l2e_get_flags(l2e) & _PAGE_PSE )
-    {
-        struct page_info *page = mfn_to_page(l2e_get_pfn(l2e));
-        unsigned int i;
-
-        for ( i = 0; i < (1u << PAGETABLE_ORDER); i++, page++ )
-            put_page_and_type(page);
-    } else
-        put_page_and_type(l2e_get_page(l2e));
-
-    return 0;
-}
-
-int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, int partial,
-                      bool defer)
-{
-    struct page_info *pg;
-
-    if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || (l3e_get_pfn(l3e) == pfn) )
-        return 1;
-
-    if ( unlikely(l3e_get_flags(l3e) & _PAGE_PSE) )
-    {
-        unsigned long mfn = l3e_get_pfn(l3e);
-        int writeable = l3e_get_flags(l3e) & _PAGE_RW;
-
-        ASSERT(!(mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1)));
-        do {
-            put_data_page(mfn_to_page(mfn), writeable);
-        } while ( ++mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1) );
-
-        return 0;
-    }
-
-    pg = l3e_get_page(l3e);
-
-    if ( unlikely(partial > 0) )
-    {
-        ASSERT(!defer);
-        return put_page_type_preemptible(pg);
-    }
-
-    if ( defer )
-    {
-        current->arch.old_guest_table = pg;
-        return 0;
-    }
-
-    return put_page_and_type_preemptible(pg);
-}
-
-int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, int partial,
-                      bool defer)
-{
-    if ( (l4e_get_flags(l4e) & _PAGE_PRESENT) &&
-         (l4e_get_pfn(l4e) != pfn) )
-    {
-        struct page_info *pg = l4e_get_page(l4e);
-
-        if ( unlikely(partial > 0) )
-        {
-            ASSERT(!defer);
-            return put_page_type_preemptible(pg);
-        }
-
-        if ( defer )
-        {
-            current->arch.old_guest_table = pg;
-            return 0;
-        }
-
-        return put_page_and_type_preemptible(pg);
-    }
-    return 1;
-}
-
 bool fill_ro_mpt(unsigned long mfn)
 {
     l4_pgentry_t *l4tab = map_domain_page(_mfn(mfn));
diff --git a/xen/arch/x86/pv/mm.c b/xen/arch/x86/pv/mm.c
index 19b2ae588e..ad35808c51 100644
--- a/xen/arch/x86/pv/mm.c
+++ b/xen/arch/x86/pv/mm.c
@@ -777,6 +777,252 @@  void pv_invalidate_shadow_ldt(struct vcpu *v, bool flush)
     spin_unlock(&v->arch.pv_vcpu.shadow_ldt_lock);
 }
 
+/*
+ * We allow root tables to map each other (a.k.a. linear page tables). It
+ * needs some special care with reference counts and access permissions:
+ *  1. The mapping entry must be read-only, or the guest may get write access
+ *     to its own PTEs.
+ *  2. We must only bump the reference counts for an *already validated*
+ *     L2 table, or we can end up in a deadlock in get_page_type() by waiting
+ *     on a validation that is required to complete that validation.
+ *  3. We only need to increment the reference counts for the mapped page
+ *     frame if it is mapped by a different root table. This is sufficient and
+ *     also necessary to allow validation of a root table mapping itself.
+ */
+#define define_get_linear_pagetable(level)                                  \
+static int                                                                  \
+get_##level##_linear_pagetable(                                             \
+    level##_pgentry_t pde, unsigned long pde_pfn, struct domain *d)         \
+{                                                                           \
+    unsigned long x, y;                                                     \
+    struct page_info *page;                                                 \
+    unsigned long pfn;                                                      \
+                                                                            \
+    if ( (level##e_get_flags(pde) & _PAGE_RW) )                             \
+    {                                                                       \
+        gdprintk(XENLOG_WARNING,                                            \
+                 "Attempt to create linear p.t. with write perms\n");       \
+        return 0;                                                           \
+    }                                                                       \
+                                                                            \
+    if ( (pfn = level##e_get_pfn(pde)) != pde_pfn )                         \
+    {                                                                       \
+        /* Make sure the mapped frame belongs to the correct domain. */     \
+        if ( unlikely(!get_page_from_mfn(_mfn(pfn), d)) )                   \
+            return 0;                                                       \
+                                                                            \
+        /*                                                                  \
+         * Ensure that the mapped frame is an already-validated page table. \
+         * If so, atomically increment the count (checking for overflow).   \
+         */                                                                 \
+        page = mfn_to_page(pfn);                                            \
+        y = page->u.inuse.type_info;                                        \
+        do {                                                                \
+            x = y;                                                          \
+            if ( unlikely((x & PGT_count_mask) == PGT_count_mask) ||        \
+                 unlikely((x & (PGT_type_mask|PGT_validated)) !=            \
+                          (PGT_##level##_page_table|PGT_validated)) )       \
+            {                                                               \
+                put_page(page);                                             \
+                return 0;                                                   \
+            }                                                               \
+        }                                                                   \
+        while ( (y = cmpxchg(&page->u.inuse.type_info, x, x + 1)) != x );   \
+    }                                                                       \
+                                                                            \
+    return 1;                                                               \
+}
+
+/* NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'. */
+/*
+ * get_page_from_l2e returns:
+ *   1 => page not present
+ *   0 => success
+ *  <0 => error code
+ */
+define_get_linear_pagetable(l2);
+int get_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn, struct domain *d)
+{
+    unsigned long mfn = l2e_get_pfn(l2e);
+    int rc;
+
+    if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
+        return 1;
+
+    if ( unlikely((l2e_get_flags(l2e) & L2_DISALLOW_MASK)) )
+    {
+        gdprintk(XENLOG_WARNING, "Bad L2 flags %x\n",
+                 l2e_get_flags(l2e) & L2_DISALLOW_MASK);
+        return -EINVAL;
+    }
+
+    if ( !(l2e_get_flags(l2e) & _PAGE_PSE) )
+    {
+        rc = get_page_and_type_from_mfn(_mfn(mfn), PGT_l1_page_table, d, 0,
+                                        false);
+        if ( unlikely(rc == -EINVAL) && get_l2_linear_pagetable(l2e, pfn, d) )
+            rc = 0;
+        return rc;
+    }
+
+    return -EINVAL;
+}
+
+/*
+ * get_page_from_l3e returns:
+ *   1 => page not present
+ *   0 => success
+ *  <0 => error code
+ */
+define_get_linear_pagetable(l3);
+int get_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, struct domain *d,
+                      int partial)
+{
+    int rc;
+
+    if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
+        return 1;
+
+    if ( unlikely((l3e_get_flags(l3e) & l3_disallow_mask(d))) )
+    {
+        gdprintk(XENLOG_WARNING, "Bad L3 flags %x\n",
+                 l3e_get_flags(l3e) & l3_disallow_mask(d));
+        return -EINVAL;
+    }
+
+    rc = get_page_and_type_from_mfn(_mfn(l3e_get_pfn(l3e)), PGT_l2_page_table,
+                                    d, partial, true);
+    if ( unlikely(rc == -EINVAL) &&
+         !is_pv_32bit_domain(d) &&
+         get_l3_linear_pagetable(l3e, pfn, d) )
+        rc = 0;
+
+    return rc;
+}
+
+/*
+ * get_page_from_l4e returns:
+ *   1 => page not present
+ *   0 => success
+ *  <0 => error code
+ */
+define_get_linear_pagetable(l4);
+int get_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, struct domain *d,
+                      int partial)
+{
+    int rc;
+
+    if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) )
+        return 1;
+
+    if ( unlikely((l4e_get_flags(l4e) & L4_DISALLOW_MASK)) )
+    {
+        gdprintk(XENLOG_WARNING, "Bad L4 flags %x\n",
+                 l4e_get_flags(l4e) & L4_DISALLOW_MASK);
+        return -EINVAL;
+    }
+
+    rc = get_page_and_type_from_mfn(_mfn(l4e_get_pfn(l4e)), PGT_l3_page_table,
+                                    d, partial, true);
+    if ( unlikely(rc == -EINVAL) && get_l4_linear_pagetable(l4e, pfn, d) )
+        rc = 0;
+
+    return rc;
+}
+
+/*
+ * NB. Virtual address 'l2e' maps to a machine address within frame 'pfn'.
+ * Note also that this automatically deals correctly with linear p.t.'s.
+ */
+int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn)
+{
+    if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) || (l2e_get_pfn(l2e) == pfn) )
+        return 1;
+
+    if ( l2e_get_flags(l2e) & _PAGE_PSE )
+    {
+        struct page_info *page = mfn_to_page(l2e_get_pfn(l2e));
+        unsigned int i;
+
+        for ( i = 0; i < (1u << PAGETABLE_ORDER); i++, page++ )
+            put_page_and_type(page);
+    } else
+        put_page_and_type(l2e_get_page(l2e));
+
+    return 0;
+}
+
+static void put_data_page(struct page_info *page, bool writeable)
+{
+    if ( writeable )
+        put_page_and_type(page);
+    else
+        put_page(page);
+}
+
+int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, int partial,
+                      bool defer)
+{
+    struct page_info *pg;
+
+    if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || (l3e_get_pfn(l3e) == pfn) )
+        return 1;
+
+    if ( unlikely(l3e_get_flags(l3e) & _PAGE_PSE) )
+    {
+        unsigned long mfn = l3e_get_pfn(l3e);
+        int writeable = l3e_get_flags(l3e) & _PAGE_RW;
+
+        ASSERT(!(mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1)));
+        do {
+            put_data_page(mfn_to_page(mfn), writeable);
+        } while ( ++mfn & ((1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) - 1) );
+
+        return 0;
+    }
+
+    pg = l3e_get_page(l3e);
+
+    if ( unlikely(partial > 0) )
+    {
+        ASSERT(!defer);
+        return put_page_type_preemptible(pg);
+    }
+
+    if ( defer )
+    {
+        current->arch.old_guest_table = pg;
+        return 0;
+    }
+
+    return put_page_and_type_preemptible(pg);
+}
+
+int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, int partial,
+                      bool defer)
+{
+    if ( (l4e_get_flags(l4e) & _PAGE_PRESENT) &&
+         (l4e_get_pfn(l4e) != pfn) )
+    {
+        struct page_info *pg = l4e_get_page(l4e);
+
+        if ( unlikely(partial > 0) )
+        {
+            ASSERT(!defer);
+            return put_page_type_preemptible(pg);
+        }
+
+        if ( defer )
+        {
+            current->arch.old_guest_table = pg;
+            return 0;
+        }
+
+        return put_page_and_type_preemptible(pg);
+    }
+    return 1;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 7480341240..4eeaf709c1 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -358,16 +358,6 @@  int  put_old_guest_table(struct vcpu *);
 int  get_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner,
                        struct domain *pg_owner);
 void put_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner);
-int get_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn, struct domain *d);
-int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn);
-int get_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, struct domain *d,
-                      int partial);
-int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, int partial,
-                      bool defer);
-int get_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, struct domain *d,
-                      int partial);
-int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, int partial,
-                      bool defer);
 void get_page_light(struct page_info *page);
 bool get_page_from_mfn(mfn_t mfn, struct domain *d);
 int get_page_and_type_from_mfn(mfn_t mfn, unsigned long type, struct domain *d,
diff --git a/xen/include/asm-x86/pv/mm.h b/xen/include/asm-x86/pv/mm.h
index 664d7c3868..fb6dbb97ee 100644
--- a/xen/include/asm-x86/pv/mm.h
+++ b/xen/include/asm-x86/pv/mm.h
@@ -103,6 +103,17 @@  int pv_free_page_type(struct page_info *page, unsigned long type,
 
 void pv_invalidate_shadow_ldt(struct vcpu *v, bool flush);
 
+int get_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn, struct domain *d);
+int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn);
+int get_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, struct domain *d,
+                      int partial);
+int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn, int partial,
+                      bool defer);
+int get_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, struct domain *d,
+                      int partial);
+int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn, int partial,
+                      bool defer);
+
 #else
 
 #include <xen/errno.h>
@@ -142,6 +153,24 @@  static inline int pv_free_page_type(struct page_info *page, unsigned long type,
 
 static inline void pv_invalidate_shadow_ldt(struct vcpu *v, bool flush) {}
 
+static inline int get_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn,
+                                    struct domain *d)
+{ return -EINVAL; }
+static inline int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn)
+{ return -EINVAL; }
+static inline int get_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn,
+                                    struct domain *d, int partial)
+{ return -EINVAL; }
+static inline int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn,
+                                    int partial, bool defer)
+{ return -EINVAL; }
+static inline int get_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn,
+                                    struct domain *d, int partial)
+{ return -EINVAL; }
+static inline int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn,
+                                    int partial, bool defer)
+{ return -EINVAL; }
+
 #endif
 
 #endif /* __X86_PV_MM_H__ */