huang...@chinatelecom.cn writes:
> From: Hyman Huang(黄勇) <huang...@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) <huang...@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();
> }
