[RFC 5/6] migration: Add dirtylimit data into migration info

[huangy81]

From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

Add dirtylimit throttle data into migration info, through
which we can observe the process of dirtylimit during
live migration.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
 include/sysemu/dirtylimit.h |  2 ++
 migration/migration.c       | 10 ++++++++++
 qapi/migration.json         | 11 ++++++++++-
 softmmu/dirtylimit.c        | 22 ++++++++++++++++++++++
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/include/sysemu/dirtylimit.h b/include/sysemu/dirtylimit.h
index 8d2c1f3..0b8dd76 100644
--- a/include/sysemu/dirtylimit.h
+++ b/include/sysemu/dirtylimit.h
@@ -34,4 +34,6 @@ void dirtylimit_set_vcpu(int cpu_index,
 void dirtylimit_set_all(uint64_t quota,
                         bool enable);
 void dirtylimit_vcpu_execute(CPUState *cpu);
+int64_t dirtylimit_throttle_us_per_full(void);
+int64_t dirtylimit_us_per_full(void);
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index 4a659b6..935179e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -61,6 +61,7 @@
 #include "sysemu/cpus.h"
 #include "yank_functions.h"
 #include "sysemu/qtest.h"
+#include "sysemu/dirtylimit.h"
 
 #define MAX_THROTTLE  (128 << 20)      /* Migration transfer speed throttling 
*/
 
@@ -1065,6 +1066,15 @@ static void populate_ram_info(MigrationInfo *info, 
MigrationState *s)
         info->ram->remaining = ram_bytes_remaining();
         info->ram->dirty_pages_rate = ram_counters.dirty_pages_rate;
     }
+
+    if (migrate_dirtylimit() && dirtylimit_in_service()) {
+        info->has_dirtylimit_throttle_us_per_full = true;
+        info->dirtylimit_throttle_us_per_full =
+                            dirtylimit_throttle_us_per_full();
+
+        info->has_dirtylimit_us_per_full = true;
+        info->dirtylimit_us_per_full = dirtylimit_us_per_full();
+    }
 }
 
 static void populate_disk_info(MigrationInfo *info)
diff --git a/qapi/migration.json b/qapi/migration.json
index 30ad413..cac4c8d 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -239,6 +239,13 @@
 #                   Present and non-empty when migration is blocked.
 #                   (since 6.0)
 #
+# @dirtylimit-throttle-us-per-full: Throttle time (us) during the period of
+#                                   dirty ring full.
+#                                   (since 7.0)
+#
+# @dirtylimit-us-per-full: Estimated the periodic time (us) of dirty ring full.
+#                          (since 7.0)
+#
 # Since: 0.14
 ##
 { 'struct': 'MigrationInfo',
@@ -256,7 +263,9 @@
            '*postcopy-blocktime' : 'uint32',
            '*postcopy-vcpu-blocktime': ['uint32'],
            '*compression': 'CompressionStats',
-           '*socket-address': ['SocketAddress'] } }
+           '*socket-address': ['SocketAddress'],
+           '*dirtylimit-throttle-us-per-full': 'int64',
+           '*dirtylimit-us-per-full': 'int64'} }
 
 ##
 # @query-migrate:
diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c
index affe993..33440c0 100644
--- a/softmmu/dirtylimit.c
+++ b/softmmu/dirtylimit.c
@@ -546,6 +546,28 @@ static struct DirtyLimitInfo *dirtylimit_query_vcpu(int 
cpu_index)
     return info;
 }
 
+/* Pick up first vcpu throttle time by default */
+int64_t dirtylimit_throttle_us_per_full(void)
+{
+    CPUState *cpu = first_cpu;
+    return cpu->throttle_us_per_full;
+}
+
+/*
+ * Estimate dirty ring full time under current dirty page rate.
+ * Return -1 if guest doesn't dirty memory.
+ */
+int64_t dirtylimit_us_per_full(void)
+{
+    uint64_t curr_rate = vcpu_dirty_rate_get(0);
+
+    if (!curr_rate) {
+        return -1;
+    }
+
+    return dirtylimit_dirty_ring_full_time(curr_rate);
+}
+
 static struct DirtyLimitInfoList *dirtylimit_query_all(void)
 {
     int i, index;
-- 
1.8.3.1