[Qemu-block] [RFC PATCH 07/12] qcow2-bitmap: add basic bitmaps info

[John Snow]

Add functions for querying the basic information inside of bitmaps.
Restructure the bitmaps flags masks to facilitate providing a list of
flags belonging to the bitmap(s) being queried.

Signed-off-by: John Snow <address@hidden>
---
 block/qcow2-bitmap.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 block/qcow2.c        |  7 +++++
 block/qcow2.h        |  1 +
 3 files changed, 87 insertions(+), 2 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 60e01abfd7..811b82743a 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -49,8 +49,28 @@
 
 /* Bitmap directory entry flags */
 #define BME_RESERVED_FLAGS 0xfffffffcU
-#define BME_FLAG_IN_USE (1U << 0)
-#define BME_FLAG_AUTO   (1U << 1)
+
+enum BME_FLAG_BITS {
+    BME_FLAG_BIT__BEGIN = 0,
+    BME_FLAG_BIT_IN_USE = BME_FLAG_BIT__BEGIN,
+    BME_FLAG_BIT_AUTO   = 1,
+    BME_FLAG_BIT_EXTRA  = 2,
+    BME_FLAG_BIT__MAX,
+};
+
+#define BME_FLAG_IN_USE (1U << BME_FLAG_BIT_IN_USE)
+#define BME_FLAG_AUTO   (1U << BME_FLAG_BIT_AUTO)
+#define BME_FLAG_EXTRA  (1U << BME_FLAG_BIT_EXTRA)
+
+/* Correlate canonical spec values to autogenerated QAPI values */
+struct {
+    uint32_t mask;
+    int qapi_value;
+} BMEFlagMap[BME_FLAG_BIT__MAX] = {
+    [BME_FLAG_BIT_IN_USE] = { BME_FLAG_IN_USE, BITMAP_FLAG_ENUM_IN_USE },
+    [BME_FLAG_BIT_AUTO]   = { BME_FLAG_AUTO,   BITMAP_FLAG_ENUM_AUTO },
+    [BME_FLAG_BIT_EXTRA]  = { BME_FLAG_EXTRA,  
BITMAP_FLAG_ENUM_EXTRA_DATA_COMPATIBLE },
+};
 
 /* bits [1, 8] U [56, 63] are reserved */
 #define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001feULL
@@ -663,6 +683,63 @@ static void del_bitmap_list(BlockDriverState *bs)
     }
 }
 
+static BitmapFlagEnumList *get_bitmap_flags(uint32_t flags)
+{
+    int i;
+    BitmapFlagEnumList *flist = NULL;
+    BitmapFlagEnumList *ftmp;
+
+    while (flags) {
+        i = ctz32(flags);
+        ftmp = g_new0(BitmapFlagEnumList, 1);
+        if (i >= BME_FLAG_BIT__BEGIN && i < BME_FLAG_BIT__MAX) {
+            ftmp->value = BMEFlagMap[i].qapi_value;
+        } else {
+            ftmp->value = BITMAP_FLAG_ENUM_UNKNOWN;
+        }
+        ftmp->next = flist;
+        flist = ftmp;
+        flags &= ~(1 << i);
+    }
+
+    return flist;
+}
+
+BitmapInfoList *qcow2_get_bitmap_info(BlockDriverState *bs)
+{
+    Qcow2BitmapList *bm_list;
+    Qcow2Bitmap *bm;
+    BitmapInfoList *info_list = NULL;
+    BitmapInfoList *tmp;
+    BitmapInfo *bitmap_info;
+
+    bm_list = get_bitmap_list(bs, NULL);
+    if (!bm_list) {
+        return info_list;
+    }
+
+    QSIMPLEQ_FOREACH(bm, bm_list, entry) {
+        bitmap_info = g_new0(BitmapInfo, 1);
+        bitmap_info->name = g_strdup(bm->name);
+        if (bm->type == BT_DIRTY_TRACKING_BITMAP) {
+            bitmap_info->type = BITMAP_TYPE_ENUM_DIRTY_TRACKING;
+        } else {
+            bitmap_info->type = BITMAP_TYPE_ENUM_UNKNOWN;
+        }
+        bitmap_info->granularity = 1 << bm->granularity_bits;
+        bitmap_info->count = bdrv_get_dirty_count(bm->dirty_bitmap);
+        bitmap_info->flags = get_bitmap_flags(bm->flags);
+        bitmap_info->has_flags = !!bitmap_info->flags;
+
+        tmp = g_new0(BitmapInfoList, 1);
+        tmp->value = bitmap_info;
+        tmp->next = info_list;
+        info_list = tmp;
+    }
+
+    return info_list;
+}
+
 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                                   void **refcount_table,
                                   int64_t *refcount_table_size)
diff --git a/block/qcow2.c b/block/qcow2.c
index 7ae9000656..0b24ecb6b2 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3960,6 +3960,7 @@ static ImageInfoSpecific 
*qcow2_get_specific_info(BlockDriverState *bs)
     BDRVQcow2State *s = bs->opaque;
     ImageInfoSpecific *spec_info;
     QCryptoBlockInfo *encrypt_info = NULL;
+    BitmapInfoList *bitmap_list = NULL;
 
     if (s->crypto != NULL) {
         encrypt_info = qcrypto_block_get_info(s->crypto, &error_abort);
@@ -4016,6 +4017,12 @@ static ImageInfoSpecific 
*qcow2_get_specific_info(BlockDriverState *bs)
         spec_info->u.qcow2.data->encrypt = qencrypt;
     }
 
+    bitmap_list = qcow2_get_bitmap_info(bs);
+    if (bitmap_list) {
+        spec_info->u.qcow2.data->has_bitmaps = true;
+        spec_info->u.qcow2.data->bitmaps = bitmap_list;
+    }
+
     return spec_info;
 }
 
diff --git a/block/qcow2.h b/block/qcow2.h
index 796a8c914b..76bf5fa55d 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -686,5 +686,6 @@ bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
                                           const char *name,
                                           Error **errp);
+BitmapInfoList *qcow2_get_bitmap_info(BlockDriverState *bs);
 
 #endif
-- 
2.14.3