[PATCH 03/14] xen/x86: Make mfn_to_gfn typesafe

[Julien Grall <julien.grall@arm.com>]

No functional changes intended.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v2:
        - Patch added
---
 xen/arch/x86/mm/p2m.c           |  2 +-
 xen/arch/x86/mm/shadow/common.c | 31 ++++++++++++++++++-------------
 xen/arch/x86/mm/shadow/multi.c  |  4 ++--
 xen/include/asm-x86/p2m.h       |  6 +++---
 4 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 9e81a30cc4..b16117dc56 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -935,7 +935,7 @@ guest_physmap_add_entry(struct domain *d, gfn_t gfn, mfn_t mfn,
         }
         if ( page_get_owner(mfn_to_page(mfn_add(mfn, i))) != d )
             continue;
-        ogfn = _gfn(mfn_to_gfn(d, mfn_add(mfn, i)));
+        ogfn = mfn_to_gfn(d, mfn_add(mfn, i));
         if ( !gfn_eq(ogfn, _gfn(INVALID_M2P_ENTRY)) &&
              !gfn_eq(ogfn, gfn_add(gfn, i)) )
         {
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 2d44855388..480fcc740d 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -474,7 +474,8 @@ static inline void trace_resync(int event, mfn_t gmfn)
     if ( tb_init_done )
     {
         /* Convert gmfn to gfn */
-        unsigned long gfn = mfn_to_gfn(current->domain, gmfn);
+        unsigned long gfn = gfn_x(mfn_to_gfn(current->domain, gmfn));
+
         __trace_var(event, 0/*!tsc*/, sizeof(gfn), &gfn);
     }
 }
@@ -986,8 +987,9 @@ static inline void trace_shadow_prealloc_unpin(struct domain *d, mfn_t smfn)
     {
         /* Convert smfn to gfn */
         unsigned long gfn;
+
         ASSERT(mfn_valid(smfn));
-        gfn = mfn_to_gfn(d, backpointer(mfn_to_page(smfn)));
+        gfn = gfn_x(mfn_to_gfn(d, backpointer(mfn_to_page(smfn))));
         __trace_var(TRC_SHADOW_PREALLOC_UNPIN, 0/*!tsc*/, sizeof(gfn), &gfn);
     }
 }
@@ -1861,7 +1863,8 @@ static inline void trace_shadow_wrmap_bf(mfn_t gmfn)
     if ( tb_init_done )
     {
         /* Convert gmfn to gfn */
-        unsigned long gfn = mfn_to_gfn(current->domain, gmfn);
+        unsigned long gfn = gfn_x(mfn_to_gfn(current->domain, gmfn));
+
         __trace_var(TRC_SHADOW_WRMAP_BF, 0/*!tsc*/, sizeof(gfn), &gfn);
     }
 }
@@ -1946,7 +1949,7 @@ int sh_remove_write_access(struct domain *d, mfn_t gmfn,
 #if SHADOW_OPTIMIZATIONS & SHOPT_WRITABLE_HEURISTIC
     if ( curr->domain == d )
     {
-        unsigned long gfn;
+        gfn_t gfn;
         /* Heuristic: there is likely to be only one writeable mapping,
          * and that mapping is likely to be in the current pagetable,
          * in the guest's linear map (on non-HIGHPTE linux and windows)*/
@@ -1969,8 +1972,9 @@ int sh_remove_write_access(struct domain *d, mfn_t gmfn,
                 GUESS(0xC0000000UL + (fault_addr >> 10), 1);
 
             /* Linux lowmem: first 896MB is mapped 1-to-1 above 0xC0000000 */
-            if ((gfn = mfn_to_gfn(d, gmfn)) < 0x38000 )
-                GUESS(0xC0000000UL + (gfn << PAGE_SHIFT), 4);
+            gfn = mfn_to_gfn(d, gmfn);
+            if ( gfn_x(gfn) < 0x38000 )
+                GUESS(0xC0000000UL + gfn_to_gaddr(gfn), 4);
 
             /* FreeBSD: Linear map at 0xBFC00000 */
             if ( level == 1 )
@@ -1987,8 +1991,9 @@ int sh_remove_write_access(struct domain *d, mfn_t gmfn,
             }
 
             /* Linux lowmem: first 896MB is mapped 1-to-1 above 0xC0000000 */
-            if ((gfn = mfn_to_gfn(d, gmfn)) < 0x38000 )
-                GUESS(0xC0000000UL + (gfn << PAGE_SHIFT), 4);
+            gfn = mfn_to_gfn(d, gmfn);
+            if ( gfn_x(gfn) < 0x38000 )
+                GUESS(0xC0000000UL + gfn_to_gaddr(gfn), 4);
 
             /* FreeBSD PAE: Linear map at 0xBF800000 */
             switch ( level )
@@ -2016,15 +2021,15 @@ int sh_remove_write_access(struct domain *d, mfn_t gmfn,
              * had it at 0xffff810000000000, and older kernels yet had it
              * at 0x0000010000000000UL */
             gfn = mfn_to_gfn(d, gmfn);
-            GUESS(0xffff880000000000UL + (gfn << PAGE_SHIFT), 4);
-            GUESS(0xffff810000000000UL + (gfn << PAGE_SHIFT), 4);
-            GUESS(0x0000010000000000UL + (gfn << PAGE_SHIFT), 4);
+            GUESS(0xffff880000000000UL + gfn_to_gaddr(gfn), 4);
+            GUESS(0xffff810000000000UL + gfn_to_gaddr(gfn), 4);
+            GUESS(0x0000010000000000UL + gfn_to_gaddr(gfn), 4);
 
             /*
              * 64bit Solaris kernel page map at
              * kpm_vbase; 0xfffffe0000000000UL
              */
-            GUESS(0xfffffe0000000000UL + (gfn << PAGE_SHIFT), 4);
+            GUESS(0xfffffe0000000000UL + gfn_to_gaddr(gfn), 4);
 
              /* FreeBSD 64bit: linear map 0xffff800000000000 */
              switch ( level )
@@ -2037,7 +2042,7 @@ int sh_remove_write_access(struct domain *d, mfn_t gmfn,
                            + ((fault_addr & VADDR_MASK) >> 27), 6); break;
              }
              /* FreeBSD 64bit: direct map at 0xffffff0000000000 */
-             GUESS(0xffffff0000000000 + (gfn << PAGE_SHIFT), 6);
+             GUESS(0xffffff0000000000 + gfn_to_gaddr(gfn), 6);
         }
 
 #undef GUESS
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 1d282c928f..8781bdcfe5 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -1076,7 +1076,7 @@ static inline void shadow_vram_get_l1e(shadow_l1e_t new_sl1e,
          || !mfn_valid(mfn) )   /* mfn can be invalid in mmio_direct */
         return;
 
-    gfn = mfn_to_gfn(d, mfn);
+    gfn = gfn_x(mfn_to_gfn(d, mfn));
     /* Page sharing not supported on shadow PTs */
     BUG_ON(SHARED_M2P(gfn));
 
@@ -1107,7 +1107,7 @@ static inline void shadow_vram_put_l1e(shadow_l1e_t old_sl1e,
          || !mfn_valid(mfn) )   /* mfn can be invalid in mmio_direct */
         return;
 
-    gfn = mfn_to_gfn(d, mfn);
+    gfn = gfn_x(mfn_to_gfn(d, mfn));
     /* Page sharing not supported on shadow PTs */
     BUG_ON(SHARED_M2P(gfn));
 
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index c3bd12020e..0157568be9 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -506,12 +506,12 @@ static inline struct page_info *get_page_from_gfn(
 }
 
 /* General conversion function from mfn to gfn */
-static inline unsigned long mfn_to_gfn(const struct domain *d, mfn_t mfn)
+static inline gfn_t mfn_to_gfn(const struct domain *d, mfn_t mfn)
 {
     if ( paging_mode_translate(d) )
-        return get_gpfn_from_mfn(mfn_x(mfn));
+        return _gfn(get_gpfn_from_mfn(mfn_x(mfn)));
     else
-        return mfn_x(mfn);
+        return _gfn(mfn_x(mfn));
 }
 
 /* Deadlock-avoidance scheme when calling get_gfn on different gfn's */
-- 
2.11.0


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