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

Implement dirtyrate calculation periodically basing on
dirty-ring and throttle virtual CPU until it reachs the quota
dirty page rate given by user.

Introduce qmp commands "set-vcpu-dirty-limit",
"cancel-vcpu-dirty-limit", "query-vcpu-dirty-limit"
to enable, disable, query dirty page limit for virtual CPU.

Meanwhile, introduce corresponding hmp commands
"set_vcpu_dirty_limit", "cancel_vcpu_dirty_limit",
"info vcpu_dirty_limit" so the feature can be more usable.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
 hmp-commands-info.hx  |  13 ++++
 hmp-commands.hx       |  32 ++++++++++
 include/monitor/hmp.h |   3 +
 qapi/migration.json   |  60 ++++++++++++++++++
 softmmu/dirtylimit.c  | 167 ++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 275 insertions(+)

diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 407a1da..5dd3001 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -863,6 +863,19 @@ SRST
     Display the vcpu dirty rate information.
 ERST
 
+    {
+        .name       = "vcpu_dirty_limit",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show dirty page limit information of all vCPU",
+        .cmd        = hmp_info_vcpu_dirty_limit,
+    },
+
+SRST
+  ``info vcpu_dirty_limit``
+    Display the vcpu dirty page limit information.
+ERST
+
 #if defined(TARGET_I386)
     {
         .name       = "sgx",
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 70a9136..416982c 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1744,3 +1744,35 @@ ERST
                       "\n\t\t\t -b to specify dirty bitmap as method of calculation)",
         .cmd        = hmp_calc_dirty_rate,
     },
+
+SRST
+``set_vcpu_dirty_limit``
+  Set dirty page rate limit on virtual CPU, the information about all the
+  virtual CPU dirty limit status can be observed with ``info vcpu_dirty_limit``
+  command.
+ERST
+
+    {
+        .name       = "set_vcpu_dirty_limit",
+        .args_type  = "dirty_rate:l,cpu_index:l?",
+        .params     = "dirty_rate [cpu_index]",
+        .help       = "set dirty page rate limit, use cpu_index to set limit on a "
+                      "\n\t\t specified virtual cpu",
+        .cmd        = hmp_set_vcpu_dirty_limit,
+    },
+
+SRST
+``cancel_vcpu_dirty_limit``
+  Cancel dirty page rate limit on virtual CPU, the information about all the
+  virtual CPU dirty limit status can be observed with ``info vcpu_dirty_limit``
+  command.
+ERST
+
+    {
+        .name       = "cancel_vcpu_dirty_limit",
+        .args_type  = "cpu_index:l?",
+        .params     = "[cpu_index]",
+        .help       = "cancel dirty page rate limit, use cpu_index to cancel limit "
+                      "\n\t\t on a specified virtual cpu",
+        .cmd        = hmp_cancel_vcpu_dirty_limit,
+    },
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 96d0148..478820e 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -131,6 +131,9 @@ void hmp_replay_delete_break(Monitor *mon, const QDict *qdict);
 void hmp_replay_seek(Monitor *mon, const QDict *qdict);
 void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict);
 void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict);
+void hmp_set_vcpu_dirty_limit(Monitor *mon, const QDict *qdict);
+void hmp_cancel_vcpu_dirty_limit(Monitor *mon, const QDict *qdict);
+void hmp_info_vcpu_dirty_limit(Monitor *mon, const QDict *qdict);
 void hmp_human_readable_text_helper(Monitor *mon,
                                     HumanReadableText *(*qmp_handler)(Error **));
 
diff --git a/qapi/migration.json b/qapi/migration.json
index ac5fa56..9d406f4 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1869,6 +1869,66 @@
             'current-rate': 'int64' } }
 
 ##
+# @set-vcpu-dirty-limit:
+#
+# Set the upper limit of dirty page rate for virtual CPU.
+#
+# Requires KVM with accelerator property "dirty-ring-size" set.
+# A virtual CPU's dirty page rate is a measure of its memory load.
+# To observe dirty page rates, use @calc-dirty-rate.
+#
+# @cpu-index: index of virtual CPU, default is all.
+#
+# @dirty-rate: upper limit of dirty page rate for virtual CPU.
+#
+# Since: 7.0
+#
+# Example:
+#   {"execute": "set-vcpu-dirty-limit"}
+#    "arguments": { "dirty-rate": 200,
+#                   "cpu-index": 1 } }
+#
+##
+{ 'command': 'set-vcpu-dirty-limit',
+  'data': { '*cpu-index': 'uint64',
+            'dirty-rate': 'uint64' } }
+
+##
+# @cancel-vcpu-dirty-limit:
+#
+# Cancel the upper limit of dirty page rate for virtual CPU.
+#
+# Cancel the dirty page limit for the vCPU which has been set with
+# set-vcpu-dirty-limit command. Note that this command requires
+# support from dirty ring, same as the "set-vcpu-dirty-limit".
+#
+# @cpu-index: index of virtual CPU, default is all.
+#
+# Since: 7.0
+#
+# Example:
+#   {"execute": "cancel-vcpu-dirty-limit"}
+#    "arguments": { "cpu-index": 1 } }
+#
+##
+{ 'command': 'cancel-vcpu-dirty-limit',
+  'data': { '*cpu-index': 'uint64'} }
+
+##
+# @query-vcpu-dirty-limit:
+#
+# Returns information about all virtual CPU dirty limit if enabled.
+#
+# Since: 7.0
+#
+# Example:
+#   {"execute": "query-vcpu-dirty-limit"}
+#
+##
+{ 'command': 'query-vcpu-dirty-limit',
+  'returns': [ 'DirtyLimitInfo' ] }
+
+##
 # @snapshot-save:
 #
 # Save a VM snapshot
diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c
index c9f5745..071f3b9 100644
--- a/softmmu/dirtylimit.c
+++ b/softmmu/dirtylimit.c
@@ -14,8 +14,12 @@
 #include "qapi/error.h"
 #include "qemu/main-loop.h"
 #include "qapi/qapi-commands-migration.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/error.h"
 #include "sysemu/dirtyrate.h"
 #include "sysemu/dirtylimit.h"
+#include "monitor/hmp.h"
+#include "monitor/monitor.h"
 #include "exec/memory.h"
 #include "hw/boards.h"
 #include "sysemu/kvm.h"
@@ -475,3 +479,166 @@ void dirtylimit_vcpu_execute(CPUState *cpu)
         usleep(cpu->throttle_us_per_full);
     }
 }
+
+void qmp_set_vcpu_dirty_limit(bool has_cpu_index,
+                              uint64_t cpu_index,
+                              uint64_t dirty_rate,
+                              Error **errp)
+{
+    if (!kvm_enabled() || !kvm_dirty_ring_enabled()) {
+        error_setg(errp, "dirty page limit feature requires KVM with"
+                   " accelerator property 'dirty-ring-size' set'");
+        return;
+    }
+
+    if (!dirtylimit_in_service()) {
+        vcpu_dirty_rate_stat_initialize();
+        vcpu_dirty_rate_stat_start();
+    }
+
+    if (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
+        error_setg(errp, "incorrect cpu index specified");
+        return;
+    }
+
+    if (has_cpu_index) {
+        dirtylimit_set_vcpu(cpu_index, dirty_rate, true);
+    } else {
+        dirtylimit_set_all(dirty_rate, true);
+    }
+}
+
+void qmp_cancel_vcpu_dirty_limit(bool has_cpu_index,
+                                 uint64_t cpu_index,
+                                 Error **errp)
+{
+    if (!kvm_enabled() || !kvm_dirty_ring_enabled()) {
+        return;
+    }
+
+    if (!dirtylimit_in_service()) {
+        return;
+    }
+
+    if (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
+        error_setg(errp, "incorrect cpu index specified");
+        return;
+    }
+
+    if (has_cpu_index) {
+        dirtylimit_set_vcpu(cpu_index, 0, false);
+    } else {
+        dirtylimit_set_all(0, false);
+    }
+
+    if (!dirtylimit_in_service()) {
+        vcpu_dirty_rate_stat_stop();
+        vcpu_dirty_rate_stat_finalize();
+    }
+}
+
+void hmp_set_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
+{
+    int64_t dirty_rate = qdict_get_int(qdict, "dirty_rate");
+    int64_t cpu_index = qdict_get_try_int(qdict, "cpu_index", -1);
+    Error *err = NULL;
+
+    qmp_set_vcpu_dirty_limit(!!(cpu_index != -1), cpu_index, dirty_rate, &err);
+    if (err) {
+        hmp_handle_error(mon, err);
+        return;
+    }
+
+    monitor_printf(mon, "[Please use 'info vcpu_dirty_limit' to query "
+                   "dirty limit for virtual CPU]\n");
+}
+
+void hmp_cancel_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
+{
+    int64_t cpu_index = qdict_get_try_int(qdict, "cpu_index", -1);
+    Error *err = NULL;
+
+    qmp_cancel_vcpu_dirty_limit(!!(cpu_index != -1), cpu_index, &err);
+    if (err) {
+        hmp_handle_error(mon, err);
+        return;
+    }
+
+    monitor_printf(mon, "[Please use 'info vcpu_dirty_limit' to query "
+                   "dirty limit for virtual CPU]\n");
+}
+
+static struct DirtyLimitInfo *dirtylimit_query_vcpu(int cpu_index)
+{
+    DirtyLimitInfo *info = NULL;
+
+    info = g_malloc0(sizeof(*info));
+    info->cpu_index = cpu_index;
+    info->limit_rate = dirtylimit_vcpu_get_state(cpu_index)->quota;
+    info->current_rate = vcpu_dirty_rate_get(cpu_index);
+
+    return info;
+}
+
+static struct DirtyLimitInfoList *dirtylimit_query_all(void)
+{
+    int i, index;
+    DirtyLimitInfo *info = NULL;
+    DirtyLimitInfoList *head = NULL, **tail = &head;
+
+    dirtylimit_state_lock();
+
+    if (!dirtylimit_in_service()) {
+        return NULL;
+    }
+
+    for (i = 0; i < dirtylimit_state->max_cpus; i++) {
+        index = dirtylimit_state->states[i].cpu_index;
+        if (dirtylimit_vcpu_get_state(index)->enabled) {
+            info = dirtylimit_query_vcpu(index);
+            QAPI_LIST_APPEND(tail, info);
+        }
+    }
+
+    dirtylimit_state_unlock();
+
+    return head;
+}
+
+struct DirtyLimitInfoList *qmp_query_vcpu_dirty_limit(Error **errp)
+{
+    if (!dirtylimit_in_service()) {
+        error_setg(errp, "dirty page limit not enabled");
+        return NULL;
+    }
+
+    return dirtylimit_query_all();
+}
+
+void hmp_info_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
+{
+    DirtyLimitInfoList *limit, *head, *info = NULL;
+    Error *err = NULL;
+
+    if (!dirtylimit_in_service()) {
+        monitor_printf(mon, "Dirty page limit not enabled!\n");
+        return;
+    }
+
+    info = qmp_query_vcpu_dirty_limit(&err);
+    if (err) {
+        hmp_handle_error(mon, err);
+        return;
+    }
+
+    head = info;
+    for (limit = head; limit != NULL; limit = limit->next) {
+        monitor_printf(mon, "vcpu[%"PRIi64"], limit rate %"PRIi64 " (MB/s),"
+                            " current rate %"PRIi64 " (MB/s)\n",
+                            limit->value->cpu_index,
+                            limit->value->limit_rate,
+                            limit->value->current_rate);
+    }
+
+    g_free(info);
+}
-- 
1.8.3.1

huangy81@chinatelecom.cn writes:

> From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
>
> Implement dirtyrate calculation periodically basing on
> dirty-ring and throttle virtual CPU until it reachs the quota
> dirty page rate given by user.
>
> Introduce qmp commands "set-vcpu-dirty-limit",
> "cancel-vcpu-dirty-limit", "query-vcpu-dirty-limit"
> to enable, disable, query dirty page limit for virtual CPU.
>
> Meanwhile, introduce corresponding hmp commands
> "set_vcpu_dirty_limit", "cancel_vcpu_dirty_limit",
> "info vcpu_dirty_limit" so the feature can be more usable.
>
> Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

[...]

> diff --git a/qapi/migration.json b/qapi/migration.json
> index ac5fa56..9d406f4 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -1869,6 +1869,66 @@
>              'current-rate': 'int64' } }
>  
>  ##
> +# @set-vcpu-dirty-limit:
> +#
> +# Set the upper limit of dirty page rate for virtual CPU.

"for virtual CPUs"

> +#
> +# Requires KVM with accelerator property "dirty-ring-size" set.
> +# A virtual CPU's dirty page rate is a measure of its memory load.
> +# To observe dirty page rates, use @calc-dirty-rate.
> +#
> +# @cpu-index: index of virtual CPU, default is all.
> +#
> +# @dirty-rate: upper limit of dirty page rate for virtual CPU.

Lacks a unit.  Is it bytes per second?  pages per second?

> +#
> +# Since: 7.0
> +#
> +# Example:
> +#   {"execute": "set-vcpu-dirty-limit"}
> +#    "arguments": { "dirty-rate": 200,
> +#                   "cpu-index": 1 } }
> +#
> +##
> +{ 'command': 'set-vcpu-dirty-limit',
> +  'data': { '*cpu-index': 'uint64',

Use 'int' for consistency with cpu-index arguments elsewhere.

> +            'dirty-rate': 'uint64' } }
> +
> +##
> +# @cancel-vcpu-dirty-limit:
> +#
> +# Cancel the upper limit of dirty page rate for virtual CPU.

"for virtual CPUs"

> +#
> +# Cancel the dirty page limit for the vCPU which has been set with
> +# set-vcpu-dirty-limit command. Note that this command requires
> +# support from dirty ring, same as the "set-vcpu-dirty-limit".
> +#
> +# @cpu-index: index of virtual CPU, default is all.
> +#
> +# Since: 7.0
> +#
> +# Example:
> +#   {"execute": "cancel-vcpu-dirty-limit"}
> +#    "arguments": { "cpu-index": 1 } }
> +#
> +##
> +{ 'command': 'cancel-vcpu-dirty-limit',
> +  'data': { '*cpu-index': 'uint64'} }

Use 'int' for consistency with cpu-index arguments elsewhere.

> +
> +##
> +# @query-vcpu-dirty-limit:
> +#
> +# Returns information about all virtual CPU dirty limit if enabled.

Suggest "about virtual CPU dirty page rate limits, if any".

> +#
> +# Since: 7.0
> +#
> +# Example:
> +#   {"execute": "query-vcpu-dirty-limit"}
> +#
> +##
> +{ 'command': 'query-vcpu-dirty-limit',
> +  'returns': [ 'DirtyLimitInfo' ] }
> +
> +##
>  # @snapshot-save:
>  #
>  # Save a VM snapshot

[...]