libqos: Update QGuestAllocator to be opaque

To avoid the architecture-specific implementations of the generic qtest
allocator having to know about fields within the allocator, add a
page_size setter method for users or arch specializations to use.
The allocator will assume a default page_size for general use, but it
can always be overridden.

Since this was the last instance of code directly using properties of the
QGuestAllocator object directly, modify the type to be opaque and move
the structure inside of malloc.c.

mlist_new, which was previously exported, is made static local to malloc.c,
as it has no external users.

[Peter Maydell <peter.maydell@linaro.org> reported the following clang
warning:
  tests/libqos/malloc.c:35:3: warning:
  redefinition of typedef 'QGuestAllocator' is a C11 feature
        [-Wtypedef-redefinition]
  } QGuestAllocator;

I converted typedef struct ... QGuestAllocator; to struct ...;
--Stefan]

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Marc Marí <marc.mari.barcelo@gmail.com>
Message-id: 1421698563-6977-7-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

tests/libqos/malloc-pc.c

@@ -38,7 +38,7 @@ QGuestAllocator *pc_alloc_init_flags(QAllocOpts flags)
 
     ram_size = qfw_cfg_get_u64(fw_cfg, FW_CFG_RAM_SIZE);
     s = alloc_init_flags(flags, 1 << 20, MIN(ram_size, 0xE0000000));
-    s->page_size = PAGE_SIZE;
+    alloc_set_page_size(s, PAGE_SIZE);
 
     /* clean-up */
     g_free(fw_cfg);

tests/libqos/malloc.c

@@ -16,6 +16,26 @@
 #include <inttypes.h>
 #include <glib.h>
 
+typedef QTAILQ_HEAD(MemList, MemBlock) MemList;
+
+typedef struct MemBlock {
+    QTAILQ_ENTRY(MemBlock) MLIST_ENTNAME;
+    uint64_t size;
+    uint64_t addr;
+} MemBlock;
+
+struct QGuestAllocator {
+    QAllocOpts opts;
+    uint64_t start;
+    uint64_t end;
+    uint32_t page_size;
+
+    MemList used;
+    MemList free;
+};
+
+#define DEFAULT_PAGE_SIZE 4096
+
 static void mlist_delete(MemList *list, MemBlock *node)
 {
     g_assert(list && node);
@@ -103,6 +123,21 @@ static void mlist_coalesce(MemList *head, MemBlock *node)
     } while (merge);
 }
 
+static MemBlock *mlist_new(uint64_t addr, uint64_t size)
+{
+    MemBlock *block;
+
+    if (!size) {
+        return NULL;
+    }
+    block = g_malloc0(sizeof(MemBlock));
+
+    block->addr = addr;
+    block->size = size;
+
+    return block;
+}
+
 static uint64_t mlist_fulfill(QGuestAllocator *s, MemBlock *freenode,
                                                                 uint64_t size)
 {
@@ -187,21 +222,6 @@ static void mlist_free(QGuestAllocator *s, uint64_t addr)
     mlist_coalesce(&s->free, node);
 }
 
-MemBlock *mlist_new(uint64_t addr, uint64_t size)
-{
-    MemBlock *block;
-
-    if (!size) {
-        return NULL;
-    }
-    block = g_malloc0(sizeof(MemBlock));
-
-    block->addr = addr;
-    block->size = size;
-
-    return block;
-}
-
 /*
  * Mostly for valgrind happiness, but it does offer
  * a chokepoint for debugging guest memory leaks, too.
@@ -283,6 +303,8 @@ QGuestAllocator *alloc_init(uint64_t start, uint64_t end)
     node = mlist_new(s->start, s->end - s->start);
     QTAILQ_INSERT_HEAD(&s->free, node, MLIST_ENTNAME);
 
+    s->page_size = DEFAULT_PAGE_SIZE;
+
     return s;
 }
 
@@ -293,3 +315,12 @@ QGuestAllocator *alloc_init_flags(QAllocOpts opts,
     s->opts = opts;
     return s;
 }
+
+void alloc_set_page_size(QGuestAllocator *allocator, size_t page_size)
+{
+    /* Can't alter the page_size for an allocator in-use */
+    g_assert(QTAILQ_EMPTY(&allocator->used));
+
+    g_assert(is_power_of_2(page_size));
+    allocator->page_size = page_size;
+}

tests/libqos/malloc.h

@@ -17,8 +17,6 @@
 #include <sys/types.h>
 #include "qemu/queue.h"
 
-#define MLIST_ENTNAME entries
-
 typedef enum {
     ALLOC_NO_FLAGS    = 0x00,
     ALLOC_LEAK_WARN   = 0x01,
@@ -26,24 +24,8 @@ typedef enum {
     ALLOC_PARANOID    = 0x04
 } QAllocOpts;
 
-typedef QTAILQ_HEAD(MemList, MemBlock) MemList;
-typedef struct MemBlock {
-    QTAILQ_ENTRY(MemBlock) MLIST_ENTNAME;
-    uint64_t size;
-    uint64_t addr;
-} MemBlock;
+typedef struct QGuestAllocator QGuestAllocator;
 
-typedef struct QGuestAllocator {
-    QAllocOpts opts;
-    uint64_t start;
-    uint64_t end;
-    uint32_t page_size;
-
-    MemList used;
-    MemList free;
-} QGuestAllocator;
-
-MemBlock *mlist_new(uint64_t addr, uint64_t size);
 void alloc_uninit(QGuestAllocator *allocator);
 
 /* Always returns page aligned values */
@@ -53,4 +35,6 @@ void guest_free(QGuestAllocator *allocator, uint64_t addr);
 QGuestAllocator *alloc_init(uint64_t start, uint64_t end);
 QGuestAllocator *alloc_init_flags(QAllocOpts flags,
                                   uint64_t start, uint64_t end);
+void alloc_set_page_size(QGuestAllocator *allocator, size_t page_size);
+
 #endif