[v5,03/23] x86/mm: move update_intpte to pv/mm.h

Commit Message

Wei Liu Sept. 14, 2017, 12:58 p.m. UTC

While at it, change the type of preserve_ad to bool.  Also move
UPDATE_ENTRY there.

Signed-off-by: Wei Liu <[e-mail]>
---
 xen/arch/x86/mm.c    | 65 ----------------------------------------------------
 xen/arch/x86/pv/mm.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 65 deletions(-)

Comments

Jan Beulich Sept. 22, 2017, 12:32 p.m. UTC | #1

>>> On 14.09.17 at 14:58, <[e-mail]> wrote:
> --- a/xen/arch/x86/pv/mm.h
> +++ b/xen/arch/x86/pv/mm.h
> @@ -18,4 +18,69 @@ static inline l1_pgentry_t guest_get_eff_l1e(unsigned long linear)
>      return l1e;
>  }
>  
> +/*
> + * PTE updates can be done with ordinary writes except:
> + *  1. Debug builds get extra checking by using CMPXCHG[8B].
> + */
> +#if !defined(NDEBUG)

#ifdef

> +#define PTE_UPDATE_WITH_CMPXCHG

#else
#undef

now that it sits in a header, to be on the safe side.

With that

Acked-by: Jan Beulich <[e-mail]>

Jan

Patch

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index faa161b767..504a0a2a6a 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -139,14 +139,6 @@ 
 l1_pgentry_t __section(".bss.page_aligned") __aligned(PAGE_SIZE)
     l1_fixmap[L1_PAGETABLE_ENTRIES];
 
-/*
- * PTE updates can be done with ordinary writes except:
- *  1. Debug builds get extra checking by using CMPXCHG[8B].
- */
-#if !defined(NDEBUG)
-#define PTE_UPDATE_WITH_CMPXCHG
-#endif
-
 paddr_t __read_mostly mem_hotplug;
 
 /* Private domain structs for DOMID_XEN and DOMID_IO. */
@@ -1848,63 +1840,6 @@  void page_unlock(struct page_info *page)
     } while ( (y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x );
 }
 
-/*
- * How to write an entry to the guest pagetables.
- * Returns false for failure (pointer not valid), true for success.
- */
-static inline bool update_intpte(
-    intpte_t *p, intpte_t old, intpte_t new, unsigned long mfn,
-    struct vcpu *v, int preserve_ad)
-{
-    bool rv = true;
-
-#ifndef PTE_UPDATE_WITH_CMPXCHG
-    if ( !preserve_ad )
-    {
-        rv = paging_write_guest_entry(v, p, new, _mfn(mfn));
-    }
-    else
-#endif
-    {
-        intpte_t t = old;
-
-        for ( ; ; )
-        {
-            intpte_t _new = new;
-
-            if ( preserve_ad )
-                _new |= old & (_PAGE_ACCESSED | _PAGE_DIRTY);
-
-            rv = paging_cmpxchg_guest_entry(v, p, &t, _new, _mfn(mfn));
-            if ( unlikely(rv == 0) )
-            {
-                gdprintk(XENLOG_WARNING,
-                         "Failed to update %" PRIpte " -> %" PRIpte
-                         ": saw %" PRIpte "\n", old, _new, t);
-                break;
-            }
-
-            if ( t == old )
-                break;
-
-            /* Allowed to change in Accessed/Dirty flags only. */
-            BUG_ON((t ^ old) & ~(intpte_t)(_PAGE_ACCESSED|_PAGE_DIRTY));
-
-            old = t;
-        }
-    }
-    return rv;
-}
-
-/*
- * Macro that wraps the appropriate type-changes around update_intpte().
- * Arguments are: type, ptr, old, new, mfn, vcpu
- */
-#define UPDATE_ENTRY(_t,_p,_o,_n,_m,_v,_ad)                         \
-    update_intpte(&_t ## e_get_intpte(*(_p)),                       \
-                  _t ## e_get_intpte(_o), _t ## e_get_intpte(_n),   \
-                  (_m), (_v), (_ad))
-
 /*
  * PTE flags that a guest may change without re-validating the PTE.
  * All other bits affect translation, caching, or Xen's safety.
diff --git a/xen/arch/x86/pv/mm.h b/xen/arch/x86/pv/mm.h
index 5b5dbff433..2563d280a5 100644
--- a/xen/arch/x86/pv/mm.h
+++ b/xen/arch/x86/pv/mm.h
@@ -18,4 +18,69 @@  static inline l1_pgentry_t guest_get_eff_l1e(unsigned long linear)
     return l1e;
 }
 
+/*
+ * PTE updates can be done with ordinary writes except:
+ *  1. Debug builds get extra checking by using CMPXCHG[8B].
+ */
+#if !defined(NDEBUG)
+#define PTE_UPDATE_WITH_CMPXCHG
+#endif
+
+/*
+ * How to write an entry to the guest pagetables.
+ * Returns false for failure (pointer not valid), true for success.
+ */
+static inline bool update_intpte(intpte_t *p, intpte_t old, intpte_t new,
+                                 unsigned long mfn, struct vcpu *v,
+                                 bool preserve_ad)
+{
+    bool rv = true;
+
+#ifndef PTE_UPDATE_WITH_CMPXCHG
+    if ( !preserve_ad )
+    {
+        rv = paging_write_guest_entry(v, p, new, _mfn(mfn));
+    }
+    else
+#endif
+    {
+        intpte_t t = old;
+
+        for ( ; ; )
+        {
+            intpte_t _new = new;
+
+            if ( preserve_ad )
+                _new |= old & (_PAGE_ACCESSED | _PAGE_DIRTY);
+
+            rv = paging_cmpxchg_guest_entry(v, p, &t, _new, _mfn(mfn));
+            if ( unlikely(rv == 0) )
+            {
+                gdprintk(XENLOG_WARNING,
+                         "Failed to update %" PRIpte " -> %" PRIpte
+                         ": saw %" PRIpte "\n", old, _new, t);
+                break;
+            }
+
+            if ( t == old )
+                break;
+
+            /* Allowed to change in Accessed/Dirty flags only. */
+            BUG_ON((t ^ old) & ~(intpte_t)(_PAGE_ACCESSED|_PAGE_DIRTY));
+
+            old = t;
+        }
+    }
+    return rv;
+}
+
+/*
+ * Macro that wraps the appropriate type-changes around update_intpte().
+ * Arguments are: type, ptr, old, new, mfn, vcpu
+ */
+#define UPDATE_ENTRY(_t,_p,_o,_n,_m,_v,_ad)                         \
+    update_intpte(&_t ## e_get_intpte(*(_p)),                       \
+                  _t ## e_get_intpte(_o), _t ## e_get_intpte(_n),   \
+                  (_m), (_v), (_ad))
+
 #endif /* __PV_MM_H__ */