tests: qemublock: Add test for bitmap detection

Test the extraction of data about changed block tracking bitmaps. The
first test case adds a simple scenario of multiple bitmaps in one layer.

The test data will be also later reused for testing the code that
determines which bitmaps to merge for an incremental backup.

The sequence of bitmaps was created by the libvirt checkpoint API with
the following sequence of commands:

virsh checkpoint-create-as VM --name a
virsh checkpoint-create-as VM --name b
virsh checkpoint-create-as VM --name c
virsh checkpoint-create-as VM --name d
virsh checkpoint-create-as VM --name current
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

tests/qemublocktest.c

@@ -27,6 +27,7 @@
 # include "virlog.h"
 # include "qemu/qemu_block.h"
 # include "qemu/qemu_qapi.h"
+# include "qemu/qemu_monitor_json.h"
 
 # include "qemu/qemu_command.h"
 
@@ -492,6 +493,71 @@ testQemuDiskXMLToPropsValidateFileSrcOnly(const void *opaque)
 }
 
 
+static const char *bitmapDetectPrefix = "qemublocktestdata/bitmap/";
+
+static void
+testQemuDetectBitmapsWorker(virHashTablePtr nodedata,
+                            const char *nodename,
+                            virBufferPtr buf)
+{
+    qemuBlockNamedNodeDataPtr data;
+    size_t i;
+
+    if (!(data = virHashLookup(nodedata, nodename)))
+        return;
+
+    virBufferAsprintf(buf, "%s:\n", nodename);
+    virBufferAdjustIndent(buf, 1);
+
+    for (i = 0; i < data->nbitmaps; i++) {
+        qemuBlockNamedNodeDataBitmapPtr bitmap = data->bitmaps[i];
+
+        virBufferAsprintf(buf, "%8s: record:%d busy:%d persist:%d inconsist:%d gran:%llu dirty:%llu\n",
+                          bitmap->name, bitmap->recording, bitmap->busy,
+                          bitmap->persistent, bitmap->inconsistent,
+                          bitmap->granularity, bitmap->dirtybytes);
+    }
+
+    virBufferAdjustIndent(buf, -1);
+}
+
+
+static int
+testQemuDetectBitmaps(const void *opaque)
+{
+    const char *name = opaque;
+    g_autoptr(virJSONValue) nodedatajson = NULL;
+    g_autoptr(virHashTable) nodedata = NULL;
+    g_autofree char *actual = NULL;
+    g_autofree char *expectpath = NULL;
+    g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
+    size_t i;
+
+    expectpath = g_strdup_printf("%s/%s%s.out", abs_srcdir,
+                                 bitmapDetectPrefix, name);
+
+    if (!(nodedatajson = virTestLoadFileJSON(bitmapDetectPrefix, name,
+                                             ".json", NULL)))
+        return -1;
+
+    if (!(nodedata = qemuMonitorJSONBlockGetNamedNodeDataJSON(nodedatajson))) {
+        VIR_TEST_VERBOSE("failed to load nodedata JSON");
+        return -1;
+    }
+
+    /* we detect for the first 30 nodenames for simplicity */
+    for (i = 0; i < 30; i++) {
+        g_autofree char *nodename = g_strdup_printf("libvirt-%zu-format", i);
+
+        testQemuDetectBitmapsWorker(nodedata, nodename, &buf);
+    }
+
+    actual = virBufferContentAndReset(&buf);
+
+    return virTestCompareToFile(actual, expectpath);
+}
+
+
 static int
 mymain(void)
 {
@@ -702,6 +768,15 @@ mymain(void)
     TEST_IMAGE_CREATE("network-ssh-qcow2", NULL);
     TEST_IMAGE_CREATE("network-sheepdog-qcow2", NULL);
 
+# define TEST_BITMAP_DETECT(testname) \
+    do { \
+        if (virTestRun("bitmap detect " testname, \
+                       testQemuDetectBitmaps, testname) < 0) \
+            ret = -1; \
+    } while (0)
+
+    TEST_BITMAP_DETECT("basic");
+
  cleanup:
     virHashFree(diskxmljsondata.schema);
     qemuTestDriverFree(&driver);

tests/qemublocktestdata/bitmap/basic.json

+[
+    {
+        "iops_rd": 0,
+        "detect_zeroes": "off",
+        "image": {
+            "virtual-size": 10485760,
+            "filename": "/tmp/pull4.qcow2",
+            "cluster-size": 65536,
+            "format": "qcow2",
+            "actual-size": 200704,
+            "format-specific": {
+                "type": "qcow2",
+                "data": {
+                    "compat": "1.1",
+                    "lazy-refcounts": false,
+                    "refcount-bits": 16,
+                    "corrupt": false
+                }
+            },
+            "dirty-flag": false
+        },
+        "iops_wr": 0,
+        "ro": false,
+        "node-name": "libvirt-1-format",
+        "backing_file_depth": 0,
+        "drv": "qcow2",
+        "iops": 0,
+        "bps_wr": 0,
+        "write_threshold": 0,
+        "dirty-bitmaps": [
+            {
+                "name": "current",
+                "recording": true,
+                "persistent": true,
+                "busy": false,
+                "status": "active",
+                "granularity": 65536,
+                "count": 0
+            },
+            {
+                "name": "d",
+                "recording": false,
+                "persistent": true,
+                "busy": false,
+                "status": "disabled",
+                "granularity": 65536,
+                "count": 0
+            },
+            {
+                "name": "c",
+                "recording": false,
+                "persistent": true,
+                "busy": false,
+                "status": "disabled",
+                "granularity": 65536,
+                "count": 0
+            },
+            {
+                "name": "b",
+                "recording": false,
+                "persistent": true,
+                "busy": false,
+                "status": "disabled",
+                "granularity": 65536,
+                "count": 0
+            },
+            {
+                "name": "a",
+                "recording": false,
+                "persistent": true,
+                "busy": false,
+                "status": "disabled",
+                "granularity": 65536,
+                "count": 0
+            }
+        ],
+        "encrypted": false,
+        "bps": 0,
+        "bps_rd": 0,
+        "cache": {
+            "no-flush": false,
+            "direct": false,
+            "writeback": true
+        },
+        "file": "/tmp/pull4.qcow2",
+        "encryption_key_missing": false
+    },
+    {
+        "iops_rd": 0,
+        "detect_zeroes": "off",
+        "image": {
+            "virtual-size": 197120,
+            "filename": "/tmp/pull4.qcow2",
+            "format": "file",
+            "actual-size": 200704,
+            "dirty-flag": false
+        },
+        "iops_wr": 0,
+        "ro": false,
+        "node-name": "libvirt-1-storage",
+        "backing_file_depth": 0,
+        "drv": "file",
+        "iops": 0,
+        "bps_wr": 0,
+        "write_threshold": 0,
+        "encrypted": false,
+        "bps": 0,
+        "bps_rd": 0,
+        "cache": {
+            "no-flush": false,
+            "direct": false,
+            "writeback": true
+        },
+        "file": "/tmp/pull4.qcow2",
+        "encryption_key_missing": false
+    }
+]

tests/qemublocktestdata/bitmap/basic.out

+libvirt-1-format:
+  current: record:1 busy:0 persist:1 inconsist:0 gran:65536 dirty:0
+        d: record:0 busy:0 persist:1 inconsist:0 gran:65536 dirty:0
+        c: record:0 busy:0 persist:1 inconsist:0 gran:65536 dirty:0
+        b: record:0 busy:0 persist:1 inconsist:0 gran:65536 dirty:0
+        a: record:0 busy:0 persist:1 inconsist:0 gran:65536 dirty:0