[Xen-devel] [PATCH v4 09/18] x86/mem_sharing: Convert MEM_SHARING_DESTROY_GFN to a bool

[Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>]

MEM_SHARING_DESTROY_GFN is used on the 'flags' bitfield during unsharing.
However, the bitfield is not used for anything else, so just convert it to a
bool instead.

Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>
---
 xen/arch/x86/mm/mem_sharing.c     | 9 ++++-----
 xen/include/asm-x86/mem_sharing.h | 5 ++---
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 84b9f130b9..0435a7f803 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1182,7 +1182,7 @@ err_out:
  */
 int __mem_sharing_unshare_page(struct domain *d,
                                unsigned long gfn,
-                               uint16_t flags)
+                               bool destroy)
 {
     p2m_type_t p2mt;
     mfn_t mfn;
@@ -1238,7 +1238,7 @@ int __mem_sharing_unshare_page(struct domain *d,
      * If the GFN is getting destroyed drop the references to MFN
      * (possibly freeing the page), and exit early.
      */
-    if ( flags & MEM_SHARING_DESTROY_GFN )
+    if ( destroy )
     {
         if ( !last_gfn )
             mem_sharing_gfn_destroy(page, d, gfn_info);
@@ -1329,9 +1329,8 @@ int relinquish_shared_pages(struct domain *d)
         mfn = p2m->get_entry(p2m, _gfn(gfn), &t, &a, 0, NULL, NULL);
         if ( mfn_valid(mfn) && p2m_is_shared(t) )
         {
-            /* Does not fail with ENOMEM given the DESTROY flag */
-            BUG_ON(__mem_sharing_unshare_page(
-                       d, gfn, MEM_SHARING_DESTROY_GFN));
+            /* Does not fail with ENOMEM given "destroy" is set to true */
+            BUG_ON(__mem_sharing_unshare_page(d, gfn, true));
             /*
              * Clear out the p2m entry so no one else may try to
              * unshare.  Must succeed: we just read the old entry and
diff --git a/xen/include/asm-x86/mem_sharing.h 
b/xen/include/asm-x86/mem_sharing.h
index 13114b6346..c915fd973f 100644
--- a/xen/include/asm-x86/mem_sharing.h
+++ b/xen/include/asm-x86/mem_sharing.h
@@ -76,16 +76,15 @@ struct page_sharing_info
 unsigned int mem_sharing_get_nr_saved_mfns(void);
 unsigned int mem_sharing_get_nr_shared_mfns(void);
 
-#define MEM_SHARING_DESTROY_GFN       (1<<1)
 /* Only fails with -ENOMEM. Enforce it with a BUG_ON wrapper. */
 int __mem_sharing_unshare_page(struct domain *d,
                                unsigned long gfn,
-                               uint16_t flags);
+                               bool destroy);
 
 static inline int mem_sharing_unshare_page(struct domain *d,
                                            unsigned long gfn)
 {
-    int rc = __mem_sharing_unshare_page(d, gfn, 0);
+    int rc = __mem_sharing_unshare_page(d, gfn, false);
     BUG_ON(rc && (rc != -ENOMEM));
     return rc;
 }
-- 
2.20.1


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