softmmu/dirtylimit: Implement dirty page rate limit

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.

"query-vcpu-dirty-limit" success depends on enabling dirty
page rate limit, so just add it to the list of skipped
command to ensure qmp-cmd-test run successfully.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <4143f26706d413dd29db0b672fe58b3d3fbe34bc.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 194 insertions, 0 deletions

diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c
index e5a4f970bd..8d98cb7f2c 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"
@@ -405,3 +409,193 @@ void dirtylimit_vcpu_execute(CPUState *cpu)
         usleep(cpu->throttle_us_per_full);
     }
 }
+
+static void dirtylimit_init(void)
+{
+    dirtylimit_state_initialize();
+    dirtylimit_change(true);
+    vcpu_dirty_rate_stat_initialize();
+    vcpu_dirty_rate_stat_start();
+}
+
+static void dirtylimit_cleanup(void)
+{
+    vcpu_dirty_rate_stat_stop();
+    vcpu_dirty_rate_stat_finalize();
+    dirtylimit_change(false);
+    dirtylimit_state_finalize();
+}
+
+void qmp_cancel_vcpu_dirty_limit(bool has_cpu_index,
+                                 int64_t cpu_index,
+                                 Error **errp)
+{
+    if (!kvm_enabled() || !kvm_dirty_ring_enabled()) {
+        return;
+    }
+
+    if (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
+        error_setg(errp, "incorrect cpu index specified");
+        return;
+    }
+
+    if (!dirtylimit_in_service()) {
+        return;
+    }
+
+    dirtylimit_state_lock();
+
+    if (has_cpu_index) {
+        dirtylimit_set_vcpu(cpu_index, 0, false);
+    } else {
+        dirtylimit_set_all(0, false);
+    }
+
+    if (!dirtylimit_state->limited_nvcpu) {
+        dirtylimit_cleanup();
+    }
+
+    dirtylimit_state_unlock();
+}
+
+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");
+}
+
+void qmp_set_vcpu_dirty_limit(bool has_cpu_index,
+                              int64_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 (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
+        error_setg(errp, "incorrect cpu index specified");
+        return;
+    }
+
+    if (!dirty_rate) {
+        qmp_cancel_vcpu_dirty_limit(has_cpu_index, cpu_index, errp);
+        return;
+    }
+
+    dirtylimit_state_lock();
+
+    if (!dirtylimit_in_service()) {
+        dirtylimit_init();
+    }
+
+    if (has_cpu_index) {
+        dirtylimit_set_vcpu(cpu_index, dirty_rate, true);
+    } else {
+        dirtylimit_set_all(dirty_rate, true);
+    }
+
+    dirtylimit_state_unlock();
+}
+
+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");
+}
+
+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()) {
+        dirtylimit_state_unlock();
+        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()) {
+        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);
+}