diff options
| -rw-r--r-- | accel/kvm/kvm-all.c | 27 | ||||
| -rw-r--r-- | docs/specs/index.rst | 1 | ||||
| -rw-r--r-- | docs/specs/rapl-msr.rst | 155 | ||||
| -rw-r--r-- | include/sysemu/kvm_int.h | 32 | ||||
| -rw-r--r-- | target/i386/cpu.h | 8 | ||||
| -rw-r--r-- | target/i386/kvm/kvm.c | 431 | ||||
| -rw-r--r-- | target/i386/kvm/meson.build | 1 | ||||
| -rw-r--r-- | target/i386/kvm/vmsr_energy.c | 345 | ||||
| -rw-r--r-- | target/i386/kvm/vmsr_energy.h | 99 |
9 files changed, 1098 insertions, 1 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 64bf47a033..480c7119d1 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -3745,6 +3745,21 @@ static void kvm_set_device(Object *obj, s->device = g_strdup(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_set_kvm_rapl_socket_path(Object *obj, + const char *str, + Error **errp) +{ + KVMState *s = KVM_STATE(obj); + g_free(s->msr_energy.socket_path); + s->msr_energy.socket_path = g_strdup(str); +} + static void kvm_accel_instance_init(Object *obj) { KVMState *s = KVM_STATE(obj); @@ -3764,6 +3779,7 @@ static void kvm_accel_instance_init(Object *obj) s->xen_gnttab_max_frames = 64; s->xen_evtchn_max_pirq = 256; s->device = NULL; + s->msr_energy.enable = false; } /** @@ -3808,6 +3824,17 @@ static void kvm_accel_class_init(ObjectClass *oc, void *data) object_class_property_set_description(oc, "device", "Path to the device node to use (default: /dev/kvm)"); + 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"); + + object_class_property_add_str(oc, "rapl-helper-socket", NULL, + kvm_set_kvm_rapl_socket_path); + object_class_property_set_description(oc, "rapl-helper-socket", + "Socket Path for comminucating with the Virtual MSR helper daemon"); + kvm_arch_accel_class_init(oc); } diff --git a/docs/specs/index.rst b/docs/specs/index.rst index 1484e3e760..e738ea7d10 100644 --- a/docs/specs/index.rst +++ b/docs/specs/index.rst @@ -33,3 +33,4 @@ guest hardware that is specific to QEMU. virt-ctlr vmcoreinfo vmgenid + rapl-msr diff --git a/docs/specs/rapl-msr.rst b/docs/specs/rapl-msr.rst new file mode 100644 index 0000000000..1202ee89be --- /dev/null +++ b/docs/specs/rapl-msr.rst @@ -0,0 +1,155 @@ +================ +RAPL MSR support +================ + +The RAPL interface (Running Average Power Limit) is 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. + +Thanks to the MSR Filtering patch [#a]_ not all MSRs are handled by KVM. Some +of them can now be handled by the userspace (QEMU). It uses a mechanism called +"MSR filtering" where a list of MSRs is given at init time of a VM to KVM so +that a callback is put in place. The design of this patch uses only this +mechanism for handling the MSRs between guest/host. + +At the moment the following MSRs are involved: + +.. code:: C + + #define MSR_RAPL_POWER_UNIT 0x00000606 + #define MSR_PKG_POWER_LIMIT 0x00000610 + #define MSR_PKG_ENERGY_STATUS 0x00000611 + #define MSR_PKG_POWER_INFO 0x00000614 + +The ``*_POWER_UNIT``, ``*_POWER_LIMIT``, ``*_POWER INFO`` are part of the RAPL +spec and specify the power limit of the package, provide range of parameter(min +power, max power,..) and also the information of the multiplier for the energy +counter to calculate the power. Those MSRs are populated once at the beginning +by reading the host CPU MSRs and are given back to the guest 1:1 when +requested. + +The MSR_PKG_ENERGY_STATUS is a counter; it represents the total amount of +energy consumed since the last time the register was cleared. If you multiply +it with the UNIT provided above you'll get the power in micro-joules. This +counter is always increasing and it increases more or less faster depending on +the consumption of the package. This counter is supposed to overflow at some +point. + +Each core belonging to the same Package reading the MSR_PKG_ENERGY_STATUS (i.e +"rdmsr 0x611") will retrieve the same value. The value represents the energy +for the whole package. Whatever Core reading it will get the same value and a +core that belongs to PKG-0 will not be able to get the value of PKG-1 and +vice-versa. + +High level implementation +------------------------- + +In order to update the value of the virtual MSR, a QEMU thread is created. +The thread is basically just an infinity loop that does: + +1. Snapshot of the time metrics of all QEMU threads (Time spent scheduled in + Userspace and System) + +2. Snapshot of the actual MSR_PKG_ENERGY_STATUS counter of all packages where + the QEMU threads are running on. + +3. Sleep for 1 second - During this pause the vcpu and other non-vcpu threads + will do what they have to do and so the energy counter will increase. + +4. Repeat 2. and 3. and calculate the delta of every metrics representing the + time spent scheduled for each QEMU thread *and* the energy spent by the + packages during the pause. + +5. Filter the vcpu threads and the non-vcpu threads. + +6. Retrieve the topology of the Virtual Machine. This helps identify which + vCPU is running on which virtual package. + +7. The total energy spent by the non-vcpu threads is divided by the number + of vcpu threads so that each vcpu thread will get an equal part of the + energy spent by the QEMU workers. + +8. Calculate the ratio of energy spent per vcpu threads. + +9. Calculate the energy for each virtual package. + +10. The virtual MSRs are updated for each virtual package. Each vCPU that + belongs to the same package will return the same value when accessing the + the MSR. + +11. Loop back to 1. + +Ratio calculation +----------------- + +In Linux, a process has an execution time associated with it. The scheduler is +dividing the time in clock ticks. The number of clock ticks per second can be +found by the sysconf system call. A typical value of clock ticks per second is +100. So a core can run a process at the maximum of 100 ticks per second. If a +package has 4 cores, 400 ticks maximum can be scheduled on all the cores +of the package for a period of 1 second. + +The /proc/[pid]/stat [#b]_ is a sysfs file that can give the executed time of a +process with the [pid] as the process ID. It gives the amount of ticks the +process has been scheduled in userspace (utime) and kernel space (stime). + +By reading those metrics for a thread, one can calculate the ratio of time the +package has spent executing the thread. + +Example: + +A 4 cores package can schedule a maximum of 400 ticks per second with 100 ticks +per second per core. If a thread was scheduled for 100 ticks between a second +on this package, that means my thread has been scheduled for 1/4 of the whole +package. With that, the calculation of the energy spent by the thread on this +package during this whole second is 1/4 of the total energy spent by the +package. + +Usage +----- + +Currently this feature is only working on an Intel CPU that has the RAPL driver +mounted and available in the sysfs. if not, QEMU fails at start-up. + +This feature is activated with -accel +kvm,rapl=true,rapl-helper-socket=/path/sock.sock + +It is important that the socket path is the same as the one +:program:`qemu-vmsr-helper` is listening to. + +qemu-vmsr-helper +---------------- + +The qemu-vmsr-helper is working very much like the qemu-pr-helper. Instead of +making persistent reservation, qemu-vmsr-helper is here to overcome the +CVE-2020-8694 which remove user access to the rapl msr attributes. + +A socket communication is established between QEMU processes that has the RAPL +MSR support activated and the qemu-vmsr-helper. A systemd service and socket +activation is provided in contrib/systemd/qemu-vmsr-helper.(service/socket). + +The systemd socket uses 600, like contrib/systemd/qemu-pr-helper.socket. The +socket can be passed via SCM_RIGHTS by libvirt, or its permissions can be +changed (e.g. 660 and root:kvm for a Debian system for example). Libvirt could +also start a separate helper if needed. All in all, the policy is left to the +user. + +See the qemu-pr-helper documentation or manpage for further details. + +Current Limitations +------------------- + +- Works only on Intel host CPUs because AMD CPUs are using different MSR + addresses. + +- Only the Package Power-Plane (MSR_PKG_ENERGY_STATUS) is reported at the + moment. + +References +---------- + +.. [#a] https://patchwork.kernel.org/project/kvm/patch/20200916202951.23760-7-graf@amazon.com/ +.. [#b] https://man7.org/linux/man-pages/man5/proc.5.html diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 3f3d13f816..1d8fb1473b 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -14,6 +14,9 @@ #include "qemu/accel.h" #include "qemu/queue.h" #include "sysemu/kvm.h" +#include "hw/boards.h" +#include "hw/i386/topology.h" +#include "io/channel-socket.h" typedef struct KVMSlot { @@ -50,6 +53,34 @@ typedef struct KVMMemoryListener { #define KVM_MSI_HASHTAB_SIZE 256 +typedef struct KVMHostTopoInfo { + /* Number of package on the Host */ + unsigned int maxpkgs; + /* Number of cpus on the Host */ + unsigned int maxcpus; + /* Number of cpus on each different package */ + unsigned int *pkg_cpu_count; + /* Each package can have different maxticks */ + unsigned int *maxticks; +} KVMHostTopoInfo; + +struct KVMMsrEnergy { + pid_t pid; + bool enable; + char *socket_path; + QIOChannelSocket *sioc; + QemuThread msr_thr; + unsigned int guest_vcpus; + unsigned int guest_vsockets; + X86CPUTopoInfo guest_topo_info; + KVMHostTopoInfo host_topo; + const CPUArchIdList *guest_cpu_list; + 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 */ @@ -117,6 +148,7 @@ struct KVMState bool kvm_dirty_ring_with_bitmap; uint64_t kvm_eager_split_size; /* Eager Page Splitting chunk size */ 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 1e121acef5..c6cc035df3 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -414,6 +414,10 @@ 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 #define MSR_ARCH_LBR_CTL 0x000014ce #define MSR_ARCH_LBR_DEPTH 0x000014cf #define MSR_ARCH_LBR_FROM_0 0x00001500 @@ -1880,6 +1884,10 @@ 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 becca2efa5..b4aab9a410 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -16,9 +16,12 @@ #include "qapi/qapi-events-run-state.h" #include "qapi/error.h" #include "qapi/visitor.h" +#include <math.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 <linux/kvm_para.h> @@ -27,6 +30,7 @@ #include "cpu.h" #include "host-cpu.h" +#include "vmsr_energy.h" #include "sysemu/sysemu.h" #include "sysemu/hw_accel.h" #include "sysemu/kvm_int.h" @@ -2559,7 +2563,8 @@ static int kvm_get_supported_msrs(KVMState *s) return ret; } -static bool kvm_rdmsr_core_thread_count(X86CPU *cpu, uint32_t msr, +static bool kvm_rdmsr_core_thread_count(X86CPU *cpu, + uint32_t msr, uint64_t *val) { CPUState *cs = CPU(cpu); @@ -2570,6 +2575,53 @@ 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; @@ -2604,6 +2656,340 @@ 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; + + g_autofree vmsr_package_energy_stat *pkg_stat = NULL; + g_autofree vmsr_thread_stat *thd_stat = NULL; + g_autofree CPUState *cpu = NULL; + g_autofree unsigned int *vpkgs_energy_stat = NULL; + unsigned int num_threads = 0; + + X86CPUTopoIDs topo_ids; + + rcu_register_thread(); + + /* Allocate memory for each package energy status */ + pkg_stat = g_new0(vmsr_package_energy_stat, vmsr->host_topo.maxpkgs); + + /* Allocate memory for thread stats */ + thd_stat = g_new0(vmsr_thread_stat, 1); + + /* Allocate memory for holding virtual package energy counter */ + vpkgs_energy_stat = g_new0(unsigned int, vmsr->guest_vsockets); + + /* Populate the max tick of each packages */ + for (int i = 0; i < vmsr->host_topo.maxpkgs; i++) { + /* + * Max numbers of ticks per package + * Time in second * Number of ticks/second * Number of cores/package + * ex: 100 ticks/second/CPU, 12 CPUs per Package gives 1200 ticks max + */ + vmsr->host_topo.maxticks[i] = (MSR_ENERGY_THREAD_SLEEP_US / 1000000) + * sysconf(_SC_CLK_TCK) + * vmsr->host_topo.pkg_cpu_count[i]; + } + + while (true) { + /* Get all qemu threads id */ + g_autofree pid_t *thread_ids = + thread_ids = vmsr_get_thread_ids(vmsr->pid, &num_threads); + + if (thread_ids == NULL) { + goto clean; + } + + thd_stat = g_renew(vmsr_thread_stat, thd_stat, num_threads); + /* Unlike g_new0, g_renew0 function doesn't exist yet... */ + memset(thd_stat, 0, num_threads * sizeof(vmsr_thread_stat)); + + /* Populate all the thread stats */ + for (int i = 0; i < num_threads; i++) { + thd_stat[i].utime = g_new0(unsigned long long, 2); + thd_stat[i].stime = g_new0(unsigned long long, 2); + thd_stat[i].thread_id = thread_ids[i]; + vmsr_read_thread_stat(vmsr->pid, + thd_stat[i].thread_id, + thd_stat[i].utime, + thd_stat[i].stime, + &thd_stat[i].cpu_id); + thd_stat[i].pkg_id = + vmsr_get_physical_package_id(thd_stat[i].cpu_id); + } + + /* Retrieve all packages power plane energy counter */ + for (int i = 0; i < vmsr->host_topo.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].pkg_id == i) { + pkg_stat[i].e_start = + vmsr_read_msr(MSR_PKG_ENERGY_STATUS, + thd_stat[j].cpu_id, + thd_stat[j].thread_id, + s->msr_energy.sioc); + 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 < vmsr->host_topo.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].pkg_id == i) { + pkg_stat[i].e_end = + vmsr_read_msr(MSR_PKG_ENERGY_STATUS, + thd_stat[j].cpu_id, + thd_stat[j].thread_id, + s->msr_energy.sioc); + /* + * Prevent the case we have migrate the VM + * during the sleep period or any other cases + * were energy counter might be lower after + * the sleep period. + */ + if (pkg_stat[i].e_end > pkg_stat[i].e_start) { + pkg_stat[i].e_delta = + pkg_stat[i].e_end - pkg_stat[i].e_start; + } else { + pkg_stat[i].e_delta = 0; + } + break; + } + } + } + + /* Delta of ticks spend by each thread between the sample */ + for (int i = 0; i < num_threads; i++) { + vmsr_read_thread_stat(vmsr->pid, + thd_stat[i].thread_id, + thd_stat[i].utime, + thd_stat[i].stime, + &thd_stat[i].cpu_id); + + if (vmsr->pid < 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 { + vmsr_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].pkg_id].nb_vcpu++; + thd_stat[i].acpi_id = kvm_arch_vcpu_id(cpu); + break; + } + } + } + + /* Retrieve the virtual package number of each vCPU */ + for (int i = 0; i < vmsr->guest_cpu_list->len; i++) { + for (int j = 0; j < num_threads; j++) { + if ((thd_stat[j].acpi_id == + vmsr->guest_cpu_list->cpus[i].arch_id) + && (thd_stat[j].is_vcpu == true)) { + x86_topo_ids_from_apicid(thd_stat[j].acpi_id, + &vmsr->guest_topo_info, &topo_ids); + thd_stat[j].vpkg_id = topo_ids.pkg_id; + } + } + } + + /* Calculate the total energy of all non-vCPU thread */ + for (int i = 0; i < num_threads; i++) { + if ((thd_stat[i].is_vcpu != true) && + (thd_stat[i].delta_ticks > 0)) { + double temp; + temp = vmsr_get_ratio(pkg_stat[thd_stat[i].pkg_id].e_delta, + thd_stat[i].delta_ticks, + vmsr->host_topo.maxticks[thd_stat[i].pkg_id]); + pkg_stat[thd_stat[i].pkg_id].e_ratio + += (uint64_t)lround(temp); + } + } + + /* Calculate the ratio per non-vCPU thread of each package */ + for (int i = 0; i < vmsr->host_topo.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 Package: + * Energy Package = sum of each vCPU energy that belongs to the package + */ + for (int i = 0; i < num_threads; i++) { + if ((thd_stat[i].is_vcpu == true) && \ + (thd_stat[i].delta_ticks > 0)) { + double temp; + temp = vmsr_get_ratio(pkg_stat[thd_stat[i].pkg_id].e_delta, + thd_stat[i].delta_ticks, + vmsr->host_topo.maxticks[thd_stat[i].pkg_id]); + vpkgs_energy_stat[thd_stat[i].vpkg_id] += + (uint64_t)lround(temp); + vpkgs_energy_stat[thd_stat[i].vpkg_id] += + pkg_stat[thd_stat[i].pkg_id].e_ratio; + } + } + + /* + * Finally populate the vmsr register of each vCPU with the total + * package value to emulate the real hardware where each CPU return the + * value of the package it belongs. + */ + for (int i = 0; i < num_threads; i++) { + if ((thd_stat[i].is_vcpu == true) && \ + (thd_stat[i].delta_ticks > 0)) { + vmsr->msr_value[thd_stat[i].vcpu_id] = \ + vpkgs_energy_stat[thd_stat[i].vpkg_id]; + } + } + + /* Freeing memory before zeroing the pointer */ + for (int i = 0; i < num_threads; i++) { + g_free(thd_stat[i].utime); + g_free(thd_stat[i].stime); + } + } + +clean: + rcu_unregister_thread(); + return NULL; +} + +static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms) +{ + MachineClass *mc = MACHINE_GET_CLASS(ms); + struct KVMMsrEnergy *r = &s->msr_energy; + int ret = 0; + + /* + * Sanity check + * 1. Host cpu must be Intel cpu + * 2. RAPL must be enabled on the Host + */ + if (is_host_cpu_intel()) { + error_report("The RAPL feature can only be enabled on hosts\ + with Intel CPU models"); + ret = 1; + goto out; + } + + if (!is_rapl_enabled()) { + ret = 1; + goto out; + } + + /* Retrieve the virtual topology */ + vmsr_init_topo_info(&r->guest_topo_info, ms); + + /* Retrieve the number of vcpu */ + r->guest_vcpus = ms->smp.cpus; + + /* Retrieve the number of virtual sockets */ + r->guest_vsockets = ms->smp.sockets; + + /* Allocate register memory (MSR_PKG_STATUS) for each vcpu */ + r->msr_value = g_new0(uint64_t, r->guest_vcpus); + + /* Retrieve the CPUArchIDlist */ + r->guest_cpu_list = mc->possible_cpu_arch_ids(ms); + + /* Max number of cpus on the Host */ + r->host_topo.maxcpus = vmsr_get_maxcpus(); + if (r->host_topo.maxcpus == 0) { + error_report("host max cpus = 0"); + ret = 1; + goto out; + } + + /* Max number of packages on the host */ + r->host_topo.maxpkgs = vmsr_get_max_physical_package(r->host_topo.maxcpus); + if (r->host_topo.maxpkgs == 0) { + error_report("host max pkgs = 0"); + ret = 1; + goto out; + } + + /* Allocate memory for each package on the host */ + r->host_topo.pkg_cpu_count = g_new0(unsigned int, r->host_topo.maxpkgs); + r->host_topo.maxticks = g_new0(unsigned int, r->host_topo.maxpkgs); + + vmsr_count_cpus_per_package(r->host_topo.pkg_cpu_count, + r->host_topo.maxpkgs); + for (int i = 0; i < r->host_topo.maxpkgs; i++) { + if (r->host_topo.pkg_cpu_count[i] == 0) { + error_report("cpu per packages = 0 on package_%d", i); + ret = 1; + goto out; + } + } + + /* Get QEMU PID*/ + r->pid = getpid(); + + /* Compute the socket path if necessary */ + if (s->msr_energy.socket_path == NULL) { + s->msr_energy.socket_path = vmsr_compute_default_paths(); + } + + /* Open socket with vmsr helper */ + s->msr_energy.sioc = vmsr_open_socket(s->msr_energy.socket_path); + + if (s->msr_energy.sioc == NULL) { + error_report("vmsr socket opening failed"); + ret = 1; + goto out; + } + + /* Those MSR values should not change */ + r->msr_unit = vmsr_read_msr(MSR_RAPL_POWER_UNIT, 0, r->pid, + s->msr_energy.sioc); + r->msr_limit = vmsr_read_msr(MSR_PKG_POWER_LIMIT, 0, r->pid, + s->msr_energy.sioc); + r->msr_info = vmsr_read_msr(MSR_PKG_POWER_INFO, 0, r->pid, + s->msr_energy.sioc); + if (r->msr_unit == 0 || r->msr_limit == 0 || r->msr_info == 0) { + error_report("can't read any virtual msr"); + ret = 1; + goto out; + } + + qemu_thread_create(&r->msr_thr, "kvm-msr", + kvm_msr_energy_thread, + s, QEMU_THREAD_JOINABLE); +out: + return ret; +} + int kvm_arch_get_default_type(MachineState *ms) { return 0; @@ -2804,6 +3190,49 @@ 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); + } + r = kvm_msr_energy_thread_init(s, ms); + if (r) { + error_report("kvm : error RAPL feature requirement not meet"); + exit(1); + } + + } } return 0; diff --git a/target/i386/kvm/meson.build b/target/i386/kvm/meson.build index e7850981e6..3996cafaf2 100644 --- a/target/i386/kvm/meson.build +++ b/target/i386/kvm/meson.build @@ -3,6 +3,7 @@ i386_kvm_ss = ss.source_set() i386_kvm_ss.add(files( 'kvm.c', 'kvm-cpu.c', + 'vmsr_energy.c', )) i386_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 0000000000..a1d78f2f2a --- /dev/null +++ b/target/i386/kvm/vmsr_energy.c @@ -0,0 +1,345 @@ +/* + * QEMU KVM support -- x86 virtual RAPL msr + * + * Copyright 2024 Red Hat, Inc. 2024 + * + * 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 "qemu/osdep.h" +#include "qemu/error-report.h" +#include "vmsr_energy.h" +#include "io/channel.h" +#include "io/channel-socket.h" +#include "hw/boards.h" +#include "cpu.h" +#include "host-cpu.h" + +char *vmsr_compute_default_paths(void) +{ + g_autofree char *state = qemu_get_local_state_dir(); + + return g_build_filename(state, "run", "qemu-vmsr-helper.sock", NULL); +} + +bool is_host_cpu_intel(void) +{ + int family, model, stepping; + char vendor[CPUID_VENDOR_SZ + 1]; + + host_cpu_vendor_fms(vendor, &family, &model, &stepping); + + return strcmp(vendor, CPUID_VENDOR_INTEL); +} + +int is_rapl_enabled(void) +{ + const char *path = "/sys/class/powercap/intel-rapl/enabled"; + FILE *file = fopen(path, "r"); + int value = 0; + + if (file != NULL) { + if (fscanf(file, "%d", &value) != 1) { + error_report("INTEL RAPL not enabled"); + } + fclose(file); + } else { + error_report("Error opening %s", path); + } + + return value; +} + +QIOChannelSocket *vmsr_open_socket(const char *path) +{ + g_autofree char *socket_path = NULL; + + socket_path = g_strdup(path); + + SocketAddress saddr = { + .type = SOCKET_ADDRESS_TYPE_UNIX, + .u.q_unix.path = socket_path + }; + + QIOChannelSocket *sioc = qio_channel_socket_new(); + Error *local_err = NULL; + + qio_channel_set_name(QIO_CHANNEL(sioc), "vmsr-helper"); + qio_channel_socket_connect_sync(sioc, + &saddr, + &local_err); + if (local_err) { + /* Close socket. */ + qio_channel_close(QIO_CHANNEL(sioc), NULL); + object_unref(OBJECT(sioc)); + sioc = NULL; + goto out; + } + + qio_channel_set_delay(QIO_CHANNEL(sioc), false); +out: + return sioc; +} + +uint64_t vmsr_read_msr(uint32_t reg, uint32_t cpu_id, uint32_t tid, + QIOChannelSocket *sioc) +{ + uint64_t data = 0; + int r = 0; + Error *local_err = NULL; + uint32_t buffer[3]; + /* + * Send the required arguments: + * 1. RAPL MSR register to read + * 2. On which CPU ID + * 3. From which vCPU (Thread ID) + */ + buffer[0] = reg; + buffer[1] = cpu_id; + buffer[2] = tid; + + r = qio_channel_write_all(QIO_CHANNEL(sioc), + (char *)buffer, sizeof(buffer), + &local_err); + if (r < 0) { + goto out_close; + } + + r = qio_channel_read(QIO_CHANNEL(sioc), + (char *)&data, sizeof(data), + &local_err); + if (r < 0) { + data = 0; + goto out_close; + } + +out_close: + return data; +} + +/* Retrieve the max number of physical package */ +unsigned int vmsr_get_max_physical_package(unsigned int max_cpus) +{ + const char *dir = "/sys/devices/system/cpu/"; + const char *topo_path = "topology/physical_package_id"; + g_autofree int *uniquePackages = g_new0(int, max_cpus); + unsigned int packageCount = 0; + FILE *file = NULL; + + for (int i = 0; i < max_cpus; i++) { + g_autofree char *filePath = NULL; + g_autofree char *cpuid = g_strdup_printf("cpu%d", i); + + filePath = g_build_filename(dir, cpuid, topo_path, NULL); + + file = fopen(filePath, "r"); + + if (file == NULL) { + error_report("Error opening physical_package_id file"); + return 0; + } + + char packageId[10]; + if (fgets(packageId, sizeof(packageId), file) == NULL) { + packageCount = 0; + } + + fclose(file); + + int currentPackageId = atoi(packageId); + + bool isUnique = true; + for (int j = 0; j < packageCount; j++) { + if (uniquePackages[j] == currentPackageId) { + isUnique = false; + break; + } + } + + if (isUnique) { + uniquePackages[packageCount] = currentPackageId; + packageCount++; + + if (packageCount >= max_cpus) { + break; + } + } + } + + return (packageCount == 0) ? 1 : packageCount; +} + +/* Retrieve the max number of physical cpu on the host */ +unsigned int vmsr_get_maxcpus(void) +{ + GDir *dir; + const gchar *entry_name; + unsigned int cpu_count = 0; + const char *path = "/sys/devices/system/cpu/"; + + dir = g_dir_open(path, 0, NULL); + if (dir == NULL) { + error_report("Unable to open cpu directory"); + return -1; + } + + while ((entry_name = g_dir_read_name(dir)) != NULL) { + if (g_ascii_strncasecmp(entry_name, "cpu", 3) == 0 && + isdigit(entry_name[3])) { + cpu_count++; + } + } + + g_dir_close(dir); + + return cpu_count; +} + +/* Count the number of physical cpu on each packages */ +unsigned int vmsr_count_cpus_per_package(unsigned int *package_count, + unsigned int max_pkgs) +{ + g_autofree char *file_contents = NULL; + g_autofree char *path = NULL; + g_autofree char *path_name = NULL; + gsize length; + + /* Iterate over cpus and count cpus in each package */ + for (int cpu_id = 0; ; cpu_id++) { + path_name = g_strdup_printf("/sys/devices/system/cpu/cpu%d/" + "topology/physical_package_id", cpu_id); + + path = g_build_filename(path_name, NULL); + + if (!g_file_get_contents(path, &file_contents, &length, NULL)) { + break; /* No more cpus */ + } + + /* Get the physical package ID for this CPU */ + int package_id = atoi(file_contents); + + /* Check if the package ID is within the known number of packages */ + if (package_id >= 0 && package_id < max_pkgs) { + /* If yes, count the cpu for this package*/ + package_count[package_id]++; + } + } + + return 0; +} + +/* Get the physical package id from a given cpu id */ +int vmsr_get_physical_package_id(int cpu_id) +{ + g_autofree char *file_contents = NULL; + g_autofree char *file_path = NULL; + int package_id = -1; + gsize length; + + file_path = g_strdup_printf("/sys/devices/system/cpu/cpu%d" + "/topology/physical_package_id", cpu_id); + + if (!g_file_get_contents(file_path, &file_contents, &length, NULL)) { + goto out; + } + + package_id = atoi(file_contents); + +out: + return package_id; +} + +/* Read the scheduled time for a given thread of a give pid */ +void vmsr_read_thread_stat(pid_t pid, + unsigned int thread_id, + unsigned long long *utime, + unsigned long long *stime, + unsigned int *cpu_id) +{ + g_autofree char *path = NULL; + g_autofree char *path_name = NULL; + + path_name = g_strdup_printf("/proc/%u/task/%d/stat", pid, thread_id); + + path = g_build_filename(path_name, NULL); + + FILE *file = fopen(path, "r"); + if (file == NULL) { + pid = -1; + return; + } + + 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", + utime, stime, cpu_id) != 3) + { + pid = -1; + return; + } + + fclose(file); + return; +} + +/* Read QEMU stat task folder to retrieve all QEMU threads ID */ +pid_t *vmsr_get_thread_ids(pid_t pid, unsigned int *num_threads) +{ + g_autofree char *task_path = g_strdup_printf("%d/task", pid); + g_autofree char *path = g_build_filename("/proc", task_path, NULL); + + DIR *dir = opendir(path); + if (dir == NULL) { + error_report("Error opening /proc/qemu/task"); + return NULL; + } + + pid_t *thread_ids = NULL; + unsigned int thread_count = 0; + + g_autofree struct dirent *ent = NULL; + while ((ent = readdir(dir)) != NULL) { + if (ent->d_name[0] == '.') { + continue; + } + pid_t tid = atoi(ent->d_name); + if (pid != tid) { + thread_ids = g_renew(pid_t, thread_ids, (thread_count + 1)); + thread_ids[thread_count] = tid; + thread_count++; + } + } + + closedir(dir); + + *num_threads = thread_count; + return thread_ids; +} + +void vmsr_delta_ticks(vmsr_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 vmsr_get_ratio(uint64_t e_delta, + unsigned long long delta_ticks, + unsigned int maxticks) +{ + return (e_delta / 100.0) * ((100.0 / maxticks) * delta_ticks); +} + +void vmsr_init_topo_info(X86CPUTopoInfo *topo_info, + const MachineState *ms) +{ + topo_info->dies_per_pkg = ms->smp.dies; + topo_info->modules_per_die = ms->smp.modules; + topo_info->cores_per_module = ms->smp.cores; + topo_info->threads_per_core = ms->smp.threads; +} + diff --git a/target/i386/kvm/vmsr_energy.h b/target/i386/kvm/vmsr_energy.h new file mode 100644 index 0000000000..16cc1f4814 --- /dev/null +++ b/target/i386/kvm/vmsr_energy.h @@ -0,0 +1,99 @@ +/* + * QEMU KVM support -- x86 virtual energy-related MSR. + * + * Copyright 2024 Red Hat, Inc. 2024 + * + * 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 <stdint.h> +#include "qemu/osdep.h" +#include "io/channel-socket.h" +#include "hw/i386/topology.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 if TID is vCPU thread + * @ cpu_id: CPU number last executed on + * @ pkg_id: package number of the CPU + * @ vcpu_id: vCPU ID + * @ vpkg: virtual package number + * @ acpi_id: APIC id of the vCPU + * @ 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 vmsr_thread_stat { + unsigned int thread_id; + bool is_vcpu; + unsigned int cpu_id; + unsigned int pkg_id; + unsigned int vpkg_id; + unsigned int vcpu_id; + unsigned long acpi_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 vmsr_package_energy_stat { + uint64_t e_start; + uint64_t e_end; + uint64_t e_delta; + uint64_t e_ratio; + unsigned int nb_vcpu; +}; + +typedef struct vmsr_thread_stat vmsr_thread_stat; +typedef struct vmsr_package_energy_stat vmsr_package_energy_stat; + +char *vmsr_compute_default_paths(void); +void vmsr_read_thread_stat(pid_t pid, + unsigned int thread_id, + unsigned long long *utime, + unsigned long long *stime, + unsigned int *cpu_id); + +QIOChannelSocket *vmsr_open_socket(const char *path); +uint64_t vmsr_read_msr(uint32_t reg, uint32_t cpu_id, + uint32_t tid, QIOChannelSocket *sioc); +void vmsr_delta_ticks(vmsr_thread_stat *thd_stat, int i); +unsigned int vmsr_get_maxcpus(void); +unsigned int vmsr_get_max_physical_package(unsigned int max_cpus); +unsigned int vmsr_count_cpus_per_package(unsigned int *package_count, + unsigned int max_pkgs); +int vmsr_get_physical_package_id(int cpu_id); +pid_t *vmsr_get_thread_ids(pid_t pid, unsigned int *num_threads); +double vmsr_get_ratio(uint64_t e_delta, + unsigned long long delta_ticks, + unsigned int maxticks); +void vmsr_init_topo_info(X86CPUTopoInfo *topo_info, const MachineState *ms); +bool is_host_cpu_intel(void); +int is_rapl_enabled(void); +#endif /* VMSR_ENERGY_H */ |