[PATCH 3/3] sysemu/xen: Allow elision of xen_hvm_modified_memory()

[Philippe Mathieu-Daudé]

Call xen_enabled() before xen_hvm_modified_memory() to let
the compiler elide its call.

Have xen_enabled() return a boolean to match its declaration
in the CONFIG_XEN_IS_POSSIBLE case.

Suggested-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/exec/ram_addr.h |  8 ++++++--
 include/sysemu/xen.h    | 15 ++-------------
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 9f2e3893f5..66e849ac4e 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -330,7 +330,9 @@ static inline void 
cpu_physical_memory_set_dirty_range(ram_addr_t start,
         }
     }
 
-    xen_hvm_modified_memory(start, length);
+    if (xen_enabled()) {
+        xen_hvm_modified_memory(start, length);
+    }
 }
 
 #if !defined(_WIN32)
@@ -406,7 +408,9 @@ uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned 
long *bitmap,
             }
         }
 
-        xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
+        if (xen_enabled()) {
+            xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
+        }
     } else {
         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : 
DIRTY_CLIENTS_NOCODE;
 
diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
index 1f797a9abe..d84a5f3551 100644
--- a/include/sysemu/xen.h
+++ b/include/sysemu/xen.h
@@ -21,24 +21,13 @@
 #endif
 
 #ifdef CONFIG_XEN_IS_POSSIBLE
-
 extern bool xen_allowed;
-
 #define xen_enabled()           (xen_allowed)
-
-void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
-
 #else /* !CONFIG_XEN_IS_POSSIBLE */
-
-#define xen_enabled() 0
-
-static inline void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length)
-{
-    /* nothing */
-}
-
+#define xen_enabled()           false
 #endif /* CONFIG_XEN_IS_POSSIBLE */
 
+void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
                    struct MemoryRegion *mr, Error **errp);
 
-- 
2.41.0