[PATCH v26 17/17] qapi: Add VFIO devices migration stats in Migration stats

[Kirti Wankhede <kwankhede@nvidia.com>]

Added amount of bytes transferred to the target VM by all VFIO devices

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
---

Note: Comments from v25 for this patch are not addressed yet.
https://www.mail-archive.com/qemu-devel@nongnu.org/msg715620.html

Alex, need more pointer on documentation part raised Markus Armbruster.


 hw/vfio/common.c            | 20 ++++++++++++++++++++
 hw/vfio/migration.c         | 10 ++++++++++
 include/qemu/vfio-helpers.h |  3 +++
 migration/migration.c       | 14 ++++++++++++++
 monitor/hmp-cmds.c          |  6 ++++++
 qapi/migration.json         | 17 +++++++++++++++++
 6 files changed, 70 insertions(+)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 7eeaa368187a..286cdaac8674 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -39,6 +39,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "migration/migration.h"
+#include "qemu/vfio-helpers.h"
 
 VFIOGroupList vfio_group_list =
     QLIST_HEAD_INITIALIZER(vfio_group_list);
@@ -292,6 +293,25 @@ const MemoryRegionOps vfio_region_ops = {
  * Device state interfaces
  */
 
+bool vfio_mig_active(void)
+{
+    VFIOGroup *group;
+    VFIODevice *vbasedev;
+
+    if (QLIST_EMPTY(&vfio_group_list)) {
+        return false;
+    }
+
+    QLIST_FOREACH(group, &vfio_group_list, next) {
+        QLIST_FOREACH(vbasedev, &group->device_list, next) {
+            if (vbasedev->migration_blocker) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
 static bool vfio_devices_all_stopped_and_saving(VFIOContainer *container)
 {
     VFIOGroup *group;
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 822b68b4e015..c4226fa8b183 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -28,6 +28,7 @@
 #include "pci.h"
 #include "trace.h"
 #include "hw/hw.h"
+#include "qemu/vfio-helpers.h"
 
 /*
  * Flags used as delimiter:
@@ -40,6 +41,8 @@
 #define VFIO_MIG_FLAG_DEV_SETUP_STATE   (0xffffffffef100003ULL)
 #define VFIO_MIG_FLAG_DEV_DATA_STATE    (0xffffffffef100004ULL)
 
+static int64_t bytes_transferred;
+
 static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count,
                                   off_t off, bool iswrite)
 {
@@ -289,6 +292,7 @@ static int vfio_save_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t *size)
         *size = data_size;
     }
 
+    bytes_transferred += data_size;
     return ret;
 }
 
@@ -770,6 +774,7 @@ static void vfio_migration_state_notifier(Notifier *notifier, void *data)
         }
 
         vfio_set_dirty_page_tracking(vbasedev, false);
+        bytes_transferred = 0;
     }
 }
 
@@ -820,6 +825,11 @@ static int vfio_migration_init(VFIODevice *vbasedev,
 
 /* ---------------------------------------------------------------------- */
 
+int64_t vfio_mig_bytes_transferred(void)
+{
+    return bytes_transferred;
+}
+
 int vfio_migration_probe(VFIODevice *vbasedev, Error **errp)
 {
     VFIOContainer *container = vbasedev->group->container;
diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h
index 1f057c2b9e40..26a7df0767b1 100644
--- a/include/qemu/vfio-helpers.h
+++ b/include/qemu/vfio-helpers.h
@@ -29,4 +29,7 @@ void qemu_vfio_pci_unmap_bar(QEMUVFIOState *s, int index, void *bar,
 int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
                            int irq_type, Error **errp);
 
+bool vfio_mig_active(void);
+int64_t vfio_mig_bytes_transferred(void);
+
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index 58a5452471f9..b204bb1f6cd9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -56,6 +56,7 @@
 #include "net/announce.h"
 #include "qemu/queue.h"
 #include "multifd.h"
+#include "qemu/vfio-helpers.h"
 
 #define MAX_THROTTLE  (32 << 20)      /* Migration transfer speed throttling */
 
@@ -996,6 +997,17 @@ static void populate_disk_info(MigrationInfo *info)
     }
 }
 
+static void populate_vfio_info(MigrationInfo *info)
+{
+#ifdef CONFIG_LINUX
+    if (vfio_mig_active()) {
+        info->has_vfio = true;
+        info->vfio = g_malloc0(sizeof(*info->vfio));
+        info->vfio->transferred = vfio_mig_bytes_transferred();
+    }
+#endif
+}
+
 static void fill_source_migration_info(MigrationInfo *info)
 {
     MigrationState *s = migrate_get_current();
@@ -1020,6 +1032,7 @@ static void fill_source_migration_info(MigrationInfo *info)
         populate_time_info(info, s);
         populate_ram_info(info, s);
         populate_disk_info(info);
+        populate_vfio_info(info);
         break;
     case MIGRATION_STATUS_COLO:
         info->has_status = true;
@@ -1028,6 +1041,7 @@ static void fill_source_migration_info(MigrationInfo *info)
     case MIGRATION_STATUS_COMPLETED:
         populate_time_info(info, s);
         populate_ram_info(info, s);
+        populate_vfio_info(info);
         break;
     case MIGRATION_STATUS_FAILED:
         info->has_status = true;
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 7711726fd222..40d60d6a6651 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -355,6 +355,12 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
         }
         monitor_printf(mon, "]\n");
     }
+
+    if (info->has_vfio) {
+        monitor_printf(mon, "vfio device transferred: %" PRIu64 " kbytes\n",
+                       info->vfio->transferred >> 10);
+    }
+
     qapi_free_MigrationInfo(info);
 }
 
diff --git a/qapi/migration.json b/qapi/migration.json
index 675f70bb6734..3535977123d3 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -147,6 +147,18 @@
             'active', 'postcopy-active', 'postcopy-paused',
             'postcopy-recover', 'completed', 'failed', 'colo',
             'pre-switchover', 'device', 'wait-unplug' ] }
+##
+# @VfioStats:
+#
+# Detailed VFIO devices migration statistics
+#
+# @transferred: amount of bytes transferred to the target VM by VFIO devices
+#
+# Since: 5.1
+#
+##
+{ 'struct': 'VfioStats',
+  'data': {'transferred': 'int' } }
 
 ##
 # @MigrationInfo:
@@ -208,11 +220,16 @@
 #
 # @socket-address: Only used for tcp, to know what the real port is (Since 4.0)
 #
+# @vfio: @VfioStats containing detailed VFIO devices migration statistics,
+#        only returned if VFIO device is present, migration is supported by all
+#         VFIO devices and status is 'active' or 'completed' (since 5.1)
+#
 # Since: 0.14.0
 ##
 { 'struct': 'MigrationInfo',
   'data': {'*status': 'MigrationStatus', '*ram': 'MigrationStats',
            '*disk': 'MigrationStats',
+           '*vfio': 'VfioStats',
            '*xbzrle-cache': 'XBZRLECacheStats',
            '*total-time': 'int',
            '*expected-downtime': 'int',
-- 
2.7.0