huangy81@chinatelecom.cn writes:
From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Implement dirtyrate calculation periodically basing on
dirty-ring and throttle vCPU until it reachs the quota
dirtyrate given by user.
Introduce qmp commands set-dirty-limit/cancel-dirty-limit to
set/cancel dirty limit on vCPU.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
cpus-common.c | 41 +++++++++++++++++++++++++++++++++++++++++
include/hw/core/cpu.h | 9 +++++++++
qapi/migration.json | 43 +++++++++++++++++++++++++++++++++++++++++++
softmmu/vl.c | 1 +
4 files changed, 94 insertions(+)
diff --git a/cpus-common.c b/cpus-common.c
index 6e73d3e..43b0078 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -23,6 +23,11 @@
#include "hw/core/cpu.h"
#include "sysemu/cpus.h"
#include "qemu/lockable.h"
+#include "sysemu/dirtylimit.h"
+#include "sysemu/cpu-throttle.h"
+#include "sysemu/kvm.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-migration.h"
static QemuMutex qemu_cpu_list_lock;
static QemuCond exclusive_cond;
@@ -352,3 +357,39 @@ void process_queued_cpu_work(CPUState *cpu)
qemu_mutex_unlock(&cpu->work_mutex);
qemu_cond_broadcast(&qemu_work_cond);
}
+
+void qmp_set_dirty_limit(int64_t idx,
+ uint64_t dirtyrate,
+ Error **errp)
+{
+ if (!kvm_dirty_ring_enabled()) {
+ error_setg(errp, "dirty ring not enable, needed by dirty restraint!");
"not enabled"
What is a "dirty restraint"?
Drop the exclamation point, please. See error.h:
* The resulting message should be a single phrase, with no newline or
* trailing punctuation.
What about "setting a dirty page limit requires ...".
+ return;
+ }
+
+ dirtylimit_calc();
+ dirtylimit_vcpu(idx, dirtyrate);
+}
+
+void qmp_cancel_dirty_limit(int64_t idx,
+ Error **errp)
+{
+ if (!kvm_dirty_ring_enabled()) {
+ error_setg(errp, "dirty ring not enable, needed by dirty restraint!");
+ return;
+ }
+
+ if (unlikely(!dirtylimit_cancel_vcpu(idx))) {
+ dirtylimit_calc_quit();
+ }
+}
+
+void dirtylimit_setup(int max_cpus)
+{
+ if (!kvm_dirty_ring_enabled()) {
This crashes unless the accelerator is kvm. Reproducer:
$ qemu-system-x86_64 -display none -accel tcg
Segmentation fault (core dumped)
+ return;
+ }
+
+ dirtylimit_calc_state_init(max_cpus);
+ dirtylimit_state_init(max_cpus);
+}
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index e948e81..11df012 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -881,6 +881,15 @@ void end_exclusive(void);
*/
void qemu_init_vcpu(CPUState *cpu);
+/**
+ * dirtylimit_setup:
+ *
+ * Initializes the global state of dirtylimit calculation and
+ * dirtylimit itself. This is prepared for vCPU dirtylimit which
+ * could be triggered during vm lifecycle.
+ */
+void dirtylimit_setup(int max_cpus);
+
#define SSTEP_ENABLE 0x1 /* Enable simulated HW single stepping */
#define SSTEP_NOIRQ 0x2 /* Do not use IRQ while single stepping */
#define SSTEP_NOTIMER 0x4 /* Do not Timers while single stepping */
diff --git a/qapi/migration.json b/qapi/migration.json
index bbfd48c..42b260e 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1850,6 +1850,49 @@
{ 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' }
##
+# @set-dirty-limit:
+#
+# Set the upper limit of dirty page rate for the interested vCPU.
"for a vCPU"
+#
+# This command could be used to cap the vCPU memory load, which is also
+# refered as "dirty page rate". Users can use set-dirty-limit unconditionally,
+# but if one want to know which vCPU is in high memory load and which vCPU
+# should be limited, "calc-dirty-rate" with "dirty-ring" mode maybe an
+# availiable method.
I think you should mention that the command fails unless dirty ring is
enabled, and a pointer to its documentation.
+#
+# @idx: vCPU index to set dirtylimit.
Please rename to @cpu-index for consistency with query-cpus-fast. Same
for cancel-dirty-limit below.
+#
+# @dirtyrate: upper limit for the specified vCPU's dirty page rate (MB/s)
In QMP, we separate words with hyphens, like @dirty-rate. Please
rename.
+#
+# Since: 6.3
7.0
+#
+# Example:
+# {"execute": "set-dirty-limit"}
+# "arguments": { "idx": 0,
+# "dirtyrate": 200 } }
+#
+##
+{ 'command': 'set-dirty-limit',
+ 'data': { 'idx': 'int', 'dirtyrate': 'uint64' } }
+
+##
+# @cancel-dirty-limit:
+#
+# Cancel the dirtylimit for the vCPU which has been set with set-dirty-limit.
"the dirty page limit"
+#
+# @idx: vCPU index to canceled the dirtylimit
+#
+# Since: 6.3
7.0
+#
+# Example:
+# {"execute": "cancel-dirty-limit"}
+# "arguments": { "idx": 0 } }
+#
+##
+{ 'command': 'cancel-dirty-limit',
+ 'data': { 'idx': 'int' } }
+
+##
# @snapshot-save:
#
# Save a VM snapshot
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 620a1f1..0f83ce3 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3777,5 +3777,6 @@ void qemu_init(int argc, char **argv, char **envp)
qemu_init_displays();
accel_setup_post(current_machine);
os_setup_post();
+ dirtylimit_setup(current_machine->smp.max_cpus);
resume_mux_open();
}