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Re: [RFC PATCH] Add support for RAPL MSRs in KVM/Qemu
|
From: |
Marcelo Tosatti |
|
Subject: |
Re: [RFC PATCH] Add support for RAPL MSRs in KVM/Qemu |
|
Date: |
Wed, 17 May 2023 12:43:59 -0300 |
On Wed, May 17, 2023 at 03:07:30PM +0200, Anthony Harivel wrote:
> Starting with the "Sandy Bridge" generation, Intel CPUs provide a RAPL
> interface (Running Average Power Limit) for advertising the accumulated
> energy consumption of various power domains (e.g. CPU packages, DRAM,
> etc.).
>
> The consumption is reported via MSRs (model specific registers) like
> MSR_PKG_ENERGY_STATUS for the CPU package power domain. These MSRs are
> 64 bits registers that represent the accumulated energy consumption in
> micro Joules. They are updated by microcode every ~1ms.
>
> For now, KVM always returns 0 when the guest requests the value of
> these MSRs. Use the KVM MSR filtering mechanism to allow QEMU handle
> these MSRs dynamically in userspace.
>
> To limit the amount of system calls for every MSR call, create a new
> thread in QEMU that updates the "virtual" MSR values asynchronously.
>
> Each vCPU has its own vMSR to reflect the independence of vCPUs. The
> thread updates the vMSR values with the ratio of energy consumed of
> the whole physical CPU package the vCPU thread runs on and the
> thread's utime and stime values.
>
> All other non-vCPU threads are also taken into account. Their energy
> consumption is evenly distributed among all vCPUs threads running on
> the same physical CPU package.
>
> This feature is activated with -accel kvm,rapl=true.
>
> Actual limitation:
> - Works only on Intel host CPU because AMD CPUs are using different MSR
> adresses.
>
> - Only the Package Power-Plane (MSR_PKG_ENERGY_STATUS) is reported at
> the moment.
>
> - Since each vCPU has an independent vMSR value, the vCPU topology must
> be changed to match that reality. There must be a single vCPU per
> virtual socket (e.g.: -smp 4,sockets=4). Accessing pkg-0 energy will
> give vCPU 0 energy, pkg-1 will give vCPU 1 energy, etc.
>
> Signed-off-by: Anthony Harivel <aharivel@redhat.com>
> ---
>
> Notes:
> Earlier this year, I've proposed a patch in linux KVM [1] in order to
> bring energy awareness in VM.
>
> Thanks to the feedback, I've worked on another solution that requires
> only a QEMU patch that make us of MSR filtering mecanism.
>
> This patch is proposed as an RFC at the moment in order to validate the
> paradigm and see if the actual limitation could be adressed in a second
> phase.
>
> Regards,
> Anthony
>
> [1]:
> https://lore.kernel.org/kvm/20230118142123.461247-1-aharivel@redhat.com/
Hi Anthony,
>
> accel/kvm/kvm-all.c | 13 ++
> include/sysemu/kvm_int.h | 11 ++
> target/i386/cpu.h | 8 +
> target/i386/kvm/kvm.c | 273 ++++++++++++++++++++++++++++++++++
> target/i386/kvm/meson.build | 1 +
> target/i386/kvm/vmsr_energy.c | 132 ++++++++++++++++
> target/i386/kvm/vmsr_energy.h | 80 ++++++++++
> 7 files changed, 518 insertions(+)
> create mode 100644 target/i386/kvm/vmsr_energy.c
> create mode 100644 target/i386/kvm/vmsr_energy.h
>
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index cf3a88d90e92..13bb2a523c5d 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -3699,6 +3699,12 @@ static void kvm_set_dirty_ring_size(Object *obj,
> Visitor *v,
> s->kvm_dirty_ring_size = value;
> }
>
> +static void kvm_set_kvm_rapl(Object *obj, bool value, Error **errp)
> +{
> + KVMState *s = KVM_STATE(obj);
> + s->msr_energy.enable = value;
> +}
> +
> static void kvm_accel_instance_init(Object *obj)
> {
> KVMState *s = KVM_STATE(obj);
> @@ -3715,6 +3721,7 @@ static void kvm_accel_instance_init(Object *obj)
> s->xen_version = 0;
> s->xen_gnttab_max_frames = 64;
> s->xen_evtchn_max_pirq = 256;
> + s->msr_energy.enable = false;
> }
>
> /**
> @@ -3755,6 +3762,12 @@ static void kvm_accel_class_init(ObjectClass *oc, void
> *data)
> object_class_property_set_description(oc, "dirty-ring-size",
> "Size of KVM dirty page ring buffer (default: 0, i.e. use bitmap)");
>
> + object_class_property_add_bool(oc, "rapl",
> + NULL,
> + kvm_set_kvm_rapl);
> + object_class_property_set_description(oc, "rapl",
> + "Allow energy related MSRs for RAPL interface in Guest");
> +
> kvm_arch_accel_class_init(oc);
> }
>
> diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h
> index a641c974ea54..cf3a01f498d7 100644
> --- a/include/sysemu/kvm_int.h
> +++ b/include/sysemu/kvm_int.h
> @@ -47,6 +47,16 @@ typedef struct KVMMemoryListener {
>
> #define KVM_MSI_HASHTAB_SIZE 256
>
> +struct KVMMsrEnergy {
> + bool enable;
> + QemuThread msr_thr;
> + int cpus;
> + uint64_t *msr_value;
> + uint64_t msr_unit;
> + uint64_t msr_limit;
> + uint64_t msr_info;
> +};
> +
> enum KVMDirtyRingReaperState {
> KVM_DIRTY_RING_REAPER_NONE = 0,
> /* The reaper is sleeping */
> @@ -116,6 +126,7 @@ struct KVMState
> uint64_t kvm_dirty_ring_bytes; /* Size of the per-vcpu dirty ring */
> uint32_t kvm_dirty_ring_size; /* Number of dirty GFNs per ring */
> struct KVMDirtyRingReaper reaper;
> + struct KVMMsrEnergy msr_energy;
> NotifyVmexitOption notify_vmexit;
> uint32_t notify_window;
> uint32_t xen_version;
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 8504aaac6807..14f9c2901680 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -396,6 +396,10 @@ typedef enum X86Seg {
> #define MSR_IA32_TSX_CTRL 0x122
> #define MSR_IA32_TSCDEADLINE 0x6e0
> #define MSR_IA32_PKRS 0x6e1
> +#define MSR_RAPL_POWER_UNIT 0x00000606
> +#define MSR_PKG_POWER_LIMIT 0x00000610
> +#define MSR_PKG_ENERGY_STATUS 0x00000611
> +#define MSR_PKG_POWER_INFO 0x00000614
Why only PKG and not all domains?
> #define MSR_ARCH_LBR_CTL 0x000014ce
> #define MSR_ARCH_LBR_DEPTH 0x000014cf
> #define MSR_ARCH_LBR_FROM_0 0x00001500
> @@ -1757,6 +1761,10 @@ typedef struct CPUArchState {
>
> uintptr_t retaddr;
>
> + /* RAPL MSR */
> + uint64_t msr_rapl_power_unit;
> + uint64_t msr_pkg_energy_status;
> +
> /* Fields up to this point are cleared by a CPU reset */
> struct {} end_reset_fields;
>
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index de531842f6b1..c79d6b811109 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -16,11 +16,16 @@
> #include "qapi/qapi-events-run-state.h"
> #include "qapi/error.h"
> #include "qapi/visitor.h"
> +#include <math.h>
> +#include <stdint.h>
> #include <sys/ioctl.h>
> #include <sys/utsname.h>
> #include <sys/syscall.h>
> +#include <sys/resource.h>
> +#include <sys/time.h>
>
> #include <linux/kvm.h>
> +#include <unistd.h>
> #include "standard-headers/asm-x86/kvm_para.h"
> #include "hw/xen/interface/arch-x86/cpuid.h"
>
> @@ -35,6 +40,7 @@
> #include "xen-emu.h"
> #include "hyperv.h"
> #include "hyperv-proto.h"
> +#include "vmsr_energy.h"
>
> #include "exec/gdbstub.h"
> #include "qemu/host-utils.h"
> @@ -2518,6 +2524,49 @@ static bool kvm_rdmsr_core_thread_count(X86CPU *cpu,
> uint32_t msr,
> return true;
> }
>
> +static bool kvm_rdmsr_rapl_power_unit(X86CPU *cpu, uint32_t msr,
> + uint64_t *val)
> +{
> +
> + CPUState *cs = CPU(cpu);
> +
> + *val = cs->kvm_state->msr_energy.msr_unit;
> +
> + return true;
> +}
> +
> +static bool kvm_rdmsr_pkg_power_limit(X86CPU *cpu, uint32_t msr,
> + uint64_t *val)
> +{
> +
> + CPUState *cs = CPU(cpu);
> +
> + *val = cs->kvm_state->msr_energy.msr_limit;
> +
> + return true;
> +}
> +
> +static bool kvm_rdmsr_pkg_power_info(X86CPU *cpu, uint32_t msr,
> + uint64_t *val)
> +{
> +
> + CPUState *cs = CPU(cpu);
> +
> + *val = cs->kvm_state->msr_energy.msr_info;
> +
> + return true;
> +}
> +
> +static bool kvm_rdmsr_pkg_energy_status(X86CPU *cpu, uint32_t msr,
> + uint64_t *val)
> +{
> +
> + CPUState *cs = CPU(cpu);
> + *val = cs->kvm_state->msr_energy.msr_value[cs->cpu_index];
> +
> + return true;
> +}
> +
> static Notifier smram_machine_done;
> static KVMMemoryListener smram_listener;
> static AddressSpace smram_address_space;
> @@ -2552,6 +2601,190 @@ static void register_smram_listener(Notifier *n, void
> *unused)
> &smram_address_space, 1, "kvm-smram");
> }
>
> +static void *kvm_msr_energy_thread(void *data)
> +{
> + KVMState *s = data;
> + struct KVMMsrEnergy *vmsr = &s->msr_energy;
> + unsigned int maxpkgs, maxcpus, maxticks;
> + package_energy_stat *pkg_stat;
> + int num_threads;
> + thread_stat *thd_stat;
> + CPUState *cpu;
> + pid_t pid;
> +
> + rcu_register_thread();
> +
> + /* Get QEMU PID*/
> + pid = getpid();
> +
> + /* Assuming those values are the same accross physical system/packages */
> + maxcpus = get_maxcpus(0); /* Number of CPUS per packages */
> + maxpkgs = numa_max_node(); /* Number of Packages on the system */
> + /* Those MSR values should not change as well */
> + vmsr->msr_unit = read_msr(MSR_RAPL_POWER_UNIT, 0);
> + vmsr->msr_limit = read_msr(MSR_PKG_POWER_LIMIT, 0);
Power limit - MSR interfaces to specify power limit, time window; lock bit,
clamp bit etc
This one can change, right? And why expose the power limit to the guest?
> + vmsr->msr_info = read_msr(MSR_PKG_POWER_INFO, 0);
> +
> + /* Allocate memory for each package energy status */
> + pkg_stat = (package_energy_stat *) calloc(maxpkgs + 1,
> + sizeof(package_energy_stat));
> +
> + /*
> + * Max numbers of ticks per package
> + * time in second * number of ticks/second * Number of cores / package
> + * ex: for 100 ticks/second/CPU, 12 CPUs per Package gives 1200 ticks max
> + */
> + maxticks = (MSR_ENERGY_THREAD_SLEEP_US / 1000000)
> + * sysconf(_SC_CLK_TCK) * maxcpus;
> +
> + while (true) {
> +
> + /* Get all qemu threads id */
> + pid_t *thread_ids = get_thread_ids(pid, &num_threads);
> +
> + if (thread_ids == NULL) {
> + return NULL;
> + }
> +
> + /* Allocate memory for each thread stats */
> + thd_stat = (thread_stat *) calloc(num_threads, sizeof(thread_stat));
> +
> + /* Populate all the thread stats */
> + for (int i = 0; i < num_threads; i++) {
> + thd_stat[i].thread_id = thread_ids[i];
> + thd_stat[i].utime = calloc(2, sizeof(unsigned long long));
> + thd_stat[i].stime = calloc(2, sizeof(unsigned long long));
> + read_thread_stat(&thd_stat[i], pid, 0);
> + thd_stat[i].numa_node_id = numa_node_of_cpu(thd_stat[i].cpu_id);
> + }
> +
> + /* Retrieve all packages power plane energy counter */
> + for (int i = 0; i <= maxpkgs; i++) {
> + for (int j = 0; j < num_threads; j++) {
> + /*
> + * Use the first thread we found that ran on the CPU
> + * of the package to read the packages energy counter
> + */
> + if (thd_stat[j].numa_node_id == i) {
> + pkg_stat[i].e_start = read_msr(MSR_PKG_ENERGY_STATUS, i);
> + break;
> + }
> + }
> + }
> +
> + /* Sleep a short period while the other threads are working */
> + usleep(MSR_ENERGY_THREAD_SLEEP_US);
> +
> + /*
> + * Retrieve all packages power plane energy counter
> + * Calculate the delta of all packages
> + */
> + for (int i = 0; i <= maxpkgs; i++) {
> + for (int j = 0; j < num_threads; j++) {
> + /*
> + * Use the first thread we found that ran on the CPU
> + * of the package to read the packages energy counter
> + */
> + if (thd_stat[j].numa_node_id == i) {
> + pkg_stat[i].e_end =
> + read_msr(MSR_PKG_ENERGY_STATUS, thd_stat[j].cpu_id);
> + pkg_stat[i].e_delta =
> + pkg_stat[i].e_end - pkg_stat[i].e_start;
> + break;
> + }
> + }
> + }
Don't get this: can you do a high level overview of how the emulated
value is calculated? (fail to see what is the relation between whether
a QEMU thread ran and whether to read or not MSR_PKG_ENERGY_STATUS).
It seems this might be simplified, and reading every 1ms might be
excessive overhead.
Independent of this question (for whatever implementation): how
accurate is the power information exposed to the guest vs actual
power consumed (might be nice to have some notion of it).
In general i think its useful to expose the information to guests.
> +
> + /* Delta of ticks spend by each thread between the sample */
> + for (int i = 0; i < num_threads; i++) {
> + if (read_thread_stat(&thd_stat[i], pid, 1) != 0) {
> + /*
> + * We don't count the dead thread
> + * i.e threads that existed before the sleep
> + * and not anymore
> + */
> + thd_stat[i].delta_ticks = 0;
> + } else {
> + delta_ticks(thd_stat, i);
> + }
> + }
> +
> + /*
> + * Identify the vCPU threads
> + * Calculate the Number of vCPU per package
> + */
> + CPU_FOREACH(cpu) {
> + for (int i = 0; i < num_threads; i++) {
> + if (cpu->thread_id == thd_stat[i].thread_id) {
> + thd_stat[i].is_vcpu = true;
> + thd_stat[i].vcpu_id = cpu->cpu_index;
> + pkg_stat[thd_stat[i].numa_node_id].nb_vcpu++;
> + break;
> + }
> + }
> + }
> +
> + /* Calculate the total energy of all non-vCPU thread */
> + for (int i = 0; i < num_threads; i++) {
> + double temp;
> + if ((thd_stat[i].is_vcpu != true) &&
> + (thd_stat[i].delta_ticks > 0)) {
> + temp = get_ratio(pkg_stat, thd_stat, maxticks, i);
> + pkg_stat[thd_stat[i].numa_node_id].e_ratio
> + += (uint64_t)lround(temp);
> + }
> + }
> +
> + /* Calculate the ratio per non-vCPU thread of each package */
> + for (int i = 0; i <= maxpkgs; i++) {
> + if (pkg_stat[i].nb_vcpu > 0) {
> + pkg_stat[i].e_ratio = pkg_stat[i].e_ratio /
> pkg_stat[i].nb_vcpu;
> + }
> + }
> +
> + /* Calculate the energy for each vCPU thread */
> + for (int i = 0; i < num_threads; i++) {
> + double temp;
> +
> + if ((thd_stat[i].is_vcpu == true) &&
> + (thd_stat[i].delta_ticks > 0)) {
> + temp = get_ratio(pkg_stat, thd_stat, maxticks, i);
> + vmsr->msr_value[thd_stat[i].vcpu_id] +=
> (uint64_t)lround(temp);
> + vmsr->msr_value[thd_stat[i].vcpu_id] \
> + += pkg_stat[thd_stat[i].numa_node_id].e_ratio;
> + }
> + }
> +
> + /* free all memory */
> + for (int i = 0; i < num_threads; i++) {
> + free(thd_stat[i].utime);
> + free(thd_stat[i].stime);
> + }
> + free(thd_stat);
> + free(thread_ids);
> + }
> +
> + rcu_unregister_thread();
> + return NULL;
> +}
> +
> +static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
> +{
> + struct KVMMsrEnergy *r = &s->msr_energy;
> +
> + /* Retrieve the number of vCPU */
> + r->cpus = ms->smp.cpus;
> +
> + /* Allocate register memory (MSR_PKG_STATUS) for each vCPU */
> + r->msr_value = calloc(r->cpus, sizeof(r->msr_value));
> +
> + qemu_thread_create(&r->msr_thr, "kvm-msr",
> + kvm_msr_energy_thread,
> + s, QEMU_THREAD_JOINABLE);
> +
> + return 0;
> +}
> +
> int kvm_arch_init(MachineState *ms, KVMState *s)
> {
> uint64_t identity_base = 0xfffbc000;
> @@ -2765,6 +2998,46 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> strerror(-ret));
> exit(1);
> }
> +
> + if (s->msr_energy.enable == true) {
> +
> + r = kvm_filter_msr(s, MSR_RAPL_POWER_UNIT,
> + kvm_rdmsr_rapl_power_unit, NULL);
> + if (!r) {
> + error_report("Could not install MSR_RAPL_POWER_UNIT \
> + handler: %s",
> + strerror(-ret));
> + exit(1);
> + }
> +
> + r = kvm_filter_msr(s, MSR_PKG_POWER_LIMIT,
> + kvm_rdmsr_pkg_power_limit, NULL);
> + if (!r) {
> + error_report("Could not install MSR_PKG_POWER_LIMIT \
> + handler: %s",
> + strerror(-ret));
> + exit(1);
> + }
> +
> + r = kvm_filter_msr(s, MSR_PKG_POWER_INFO,
> + kvm_rdmsr_pkg_power_info, NULL);
> + if (!r) {
> + error_report("Could not install MSR_PKG_POWER_INFO \
> + handler: %s",
> + strerror(-ret));
> + exit(1);
> + }
> + r = kvm_filter_msr(s, MSR_PKG_ENERGY_STATUS,
> + kvm_rdmsr_pkg_energy_status, NULL);
> + if (!r) {
> + error_report("Could not install MSR_PKG_ENERGY_STATUS \
> + handler: %s",
> + strerror(-ret));
> + exit(1);
> + } else {
> + kvm_msr_energy_thread_init(s, ms);
> + }
> + }
> }
>
> return 0;
> diff --git a/target/i386/kvm/meson.build b/target/i386/kvm/meson.build
> index 322272091bce..9cdc93c6c439 100644
> --- a/target/i386/kvm/meson.build
> +++ b/target/i386/kvm/meson.build
> @@ -5,6 +5,7 @@ i386_softmmu_kvm_ss = ss.source_set()
> i386_softmmu_kvm_ss.add(files(
> 'kvm.c',
> 'kvm-cpu.c',
> + 'vmsr_energy.c',
> ))
>
> i386_softmmu_kvm_ss.add(when: 'CONFIG_XEN_EMU', if_true: files('xen-emu.c'))
> diff --git a/target/i386/kvm/vmsr_energy.c b/target/i386/kvm/vmsr_energy.c
> new file mode 100644
> index 000000000000..8bd86b32becf
> --- /dev/null
> +++ b/target/i386/kvm/vmsr_energy.c
> @@ -0,0 +1,132 @@
> +/*
> + * QEMU KVM support -- x86 virtual energy-related MSR.
> + *
> + * Copyright 2023 Red Hat, Inc. 2023
> + *
> + * Author:
> + * Anthony Harivel <aharivel@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include "vmsr_energy.h"
> +
> +#define MAX_PATH_LEN 50
> +#define MAX_LINE_LEN 500
> +
> +uint64_t read_msr(uint32_t reg, unsigned int cpu_id)
> +{
> + int fd;
> + uint64_t data;
> +
> + char path[MAX_PATH_LEN];
> + snprintf(path, MAX_PATH_LEN, "/dev/cpu/%u/msr", cpu_id);
> +
> + fd = open(path , O_RDONLY);
> + if (fd < 0) {
> + return 0;
> + }
> + if (pread(fd, &data, sizeof data, reg) != sizeof data) {
> + data = 0;
> + }
> +
> + close(fd);
> + return data;
> +}
> +
> +/* Retrieve the number of physical CPU on the package */
> +unsigned int get_maxcpus(unsigned int package_num)
> +{
> + int k, ncpus;
> + unsigned int maxcpus;
> + struct bitmask *cpus;
> +
> + cpus = numa_allocate_cpumask();
> + ncpus = cpus->size;
> +
> + if (numa_node_to_cpus(package_num, cpus) < 0) {
> + printf("node %u failed to convert\n", package_num);
> + }
> +
> + maxcpus = 0;
> + for (k = 0; k < ncpus; k++) {
> + if (numa_bitmask_isbitset(cpus, k)) {
> + maxcpus++;
> + }
> + }
> +
> + return maxcpus;
> +}
> +
> +int read_thread_stat(struct thread_stat *thread, int pid, int index)
> +{
> + char path[MAX_PATH_LEN];
> + snprintf(path, MAX_PATH_LEN, "/proc/%u/task/%d/stat", pid, \
> + thread->thread_id);
> +
> + FILE *file = fopen(path, "r");
> + if (file == NULL) {
> + return -1;
> + }
> +
> + if (fscanf(file, "%*d (%*[^)]) %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u
> %*u"
> + " %llu %llu %*d %*d %*d %*d %*d %*d %*u %*u %*d %*u %*u"
> + " %*u %*u %*u %*u %*u %*u %*u %*u %*u %*d %*u %*u %u",
> + &thread->utime[index], &thread->stime[index], &thread->cpu_id) !=
> 3)
> + return -1;
> +
> + fclose(file);
> + return 0;
> +}
> +
> +/* Read QEMU stat task folder to retrieve all QEMU threads ID */
> +pid_t *get_thread_ids(pid_t pid, int *num_threads)
> +{
> + char path[100];
> + sprintf(path, "/proc/%d/task", pid);
> +
> + DIR *dir = opendir(path);
> + if (dir == NULL) {
> + perror("opendir");
> + return NULL;
> + }
> +
> + pid_t *thread_ids = NULL;
> + int thread_count = 0;
> +
> + struct dirent *ent;
> + while ((ent = readdir(dir)) != NULL) {
> + if (ent->d_name[0] == '.') {
> + continue;
> + }
> + pid_t tid = atoi(ent->d_name);
> + if (pid != tid) {
> + thread_ids = realloc(thread_ids,
> + (thread_count + 1) * sizeof(pid_t));
> + thread_ids[thread_count] = tid;
> + thread_count++;
> + }
> + }
> +
> + closedir(dir);
> +
> + *num_threads = thread_count;
> + return thread_ids;
> +}
> +
> +void delta_ticks(thread_stat *thd_stat, int i)
> +{
> + thd_stat[i].delta_ticks = (thd_stat[i].utime[1] + thd_stat[i].stime[1])
> + - (thd_stat[i].utime[0] + thd_stat[i].stime[0]);
> +}
> +
> +double get_ratio(package_energy_stat *pkg_stat,
> + thread_stat *thd_stat,
> + int maxticks, int i) {
> +
> + return (pkg_stat[thd_stat[i].numa_node_id].e_delta / 100.0)
> + * ((100.0 / maxticks) * thd_stat[i].delta_ticks);
> +}
> +
> diff --git a/target/i386/kvm/vmsr_energy.h b/target/i386/kvm/vmsr_energy.h
> new file mode 100644
> index 000000000000..5f79d2cbe00d
> --- /dev/null
> +++ b/target/i386/kvm/vmsr_energy.h
> @@ -0,0 +1,80 @@
> +/*
> + * QEMU KVM support -- x86 virtual energy-related MSR.
> + *
> + * Copyright 2023 Red Hat, Inc. 2023
> + *
> + * Author:
> + * Anthony Harivel <aharivel@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#ifndef VMSR_ENERGY_H
> +#define VMSR_ENERGY_H
> +
> +#include "qemu/osdep.h"
> +
> +#include <numa.h>
> +
> +/*
> + * Define the interval time in micro seconds between 2 samples of
> + * energy related MSRs
> + */
> +#define MSR_ENERGY_THREAD_SLEEP_US 1000000.0
> +
> +/*
> + * Thread statistic
> + * @ thread_id: TID (thread ID)
> + * @ is_vcpu: true is thread is vCPU thread
> + * @ cpu_id: CPU number last executed on
> + * @ vcpu_id: vCPU ID
> + * @ numa_node_id:node number of the CPU
> + * @ utime: amount of clock ticks the thread
> + * has been scheduled in User mode
> + * @ stime: amount of clock ticks the thread
> + * has been scheduled in System mode
> + * @ delta_ticks: delta of utime+stime between
> + * the two samples (before/after sleep)
> + */
> +struct thread_stat {
> + unsigned int thread_id;
> + bool is_vcpu;
> + unsigned int cpu_id;
> + unsigned int vcpu_id;
> + unsigned int numa_node_id;
> + unsigned long long *utime;
> + unsigned long long *stime;
> + unsigned long long delta_ticks;
> +};
> +
> +/*
> + * Package statistic
> + * @ e_start: package energy counter before the sleep
> + * @ e_end: package energy counter after the sleep
> + * @ e_delta: delta of package energy counter
> + * @ e_ratio: store the energy ratio of non-vCPU thread
> + * @ nb_vcpu: number of vCPU running on this package
> + */
> +struct packge_energy_stat {
> + uint64_t e_start;
> + uint64_t e_end;
> + uint64_t e_delta;
> + uint64_t e_ratio;
> + unsigned int nb_vcpu;
> +};
> +
> +typedef struct thread_stat thread_stat;
> +typedef struct packge_energy_stat package_energy_stat;
> +
> +uint64_t read_msr(uint32_t reg, unsigned int cpu_id);
> +void delta_ticks(thread_stat *thd_stat, int i);
> +unsigned int get_maxcpus(unsigned int package_num);
> +int read_thread_stat(struct thread_stat *thread, int pid, int index);
> +pid_t *get_thread_ids(pid_t pid, int *num_threads);
> +double get_ratio(package_energy_stat *pkg_stat,
> + thread_stat *thd_stat,
> + int maxticks, int i);
> +
> +#endif /* VMSR_ENERGY_H */
> --
> 2.40.1
>
>
Re: [RFC PATCH] Add support for RAPL MSRs in KVM/Qemu, Philippe Mathieu-Daudé, 2023/05/19