examples/vm_power_manager/channel_monitor.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/select.h>
#ifdef USE_JANSSON
#include <jansson.h>
#else
#pragma message "Jansson dev libs unavailable, not including JSON parsing"
#endif
#include <rte_string_fns.h>
#include <rte_log.h>
#include <rte_memory.h>
#include <rte_malloc.h>
#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_ethdev.h>
#ifdef RTE_LIBRTE_I40E_PMD
#include <rte_pmd_i40e.h>
#endif
#include <rte_power.h>

#include <libvirt/libvirt.h>
#include "channel_monitor.h"
#include "channel_manager.h"
#include "power_manager.h"
#include "oob_monitor.h"

#define RTE_LOGTYPE_CHANNEL_MONITOR RTE_LOGTYPE_USER1

#define MAX_EVENTS 256

uint64_t vsi_pkt_count_prev[384];
uint64_t rdtsc_prev[384];
#define MAX_JSON_STRING_LEN 1024
char json_data[MAX_JSON_STRING_LEN];

double time_period_ms = 1;
static volatile unsigned run_loop = 1;
static int global_event_fd;
static unsigned int policy_is_set;
static struct epoll_event *global_events_list;
static struct policy policies[RTE_MAX_LCORE];

#ifdef USE_JANSSON

union PFID {
    struct rte_ether_addr addr;
    uint64_t pfid;
};

static int
str_to_ether_addr(const char *a, struct rte_ether_addr *ether_addr)
{
    int i;
    char *end;
    unsigned long o[RTE_ETHER_ADDR_LEN];

    i = 0;
    do {
        errno = 0;
        o[i] = strtoul(a, &end, 16);
        if (errno != 0 || end == a || (end[0] != ':' && end[0] != 0))
            return -1;
        a = end + 1;
    } while (++i != RTE_DIM(o) / sizeof(o[0]) && end[0] != 0);

    /* Junk at the end of line */
    if (end[0] != 0)
        return -1;

    /* Support the format XX:XX:XX:XX:XX:XX */
    if (i == RTE_ETHER_ADDR_LEN) {
        while (i-- != 0) {
            if (o[i] > UINT8_MAX)
                return -1;
            ether_addr->addr_bytes[i] = (uint8_t)o[i];
        }
    /* Support the format XXXX:XXXX:XXXX */
    } else if (i == RTE_ETHER_ADDR_LEN / 2) {
        while (i-- != 0) {
            if (o[i] > UINT16_MAX)
                return -1;
            ether_addr->addr_bytes[i * 2] =
                    (uint8_t)(o[i] >> 8);
            ether_addr->addr_bytes[i * 2 + 1] =
                    (uint8_t)(o[i] & 0xff);
        }
    /* unknown format */
    } else
        return -1;

    return 0;
}

static int
set_policy_mac(struct rte_power_channel_packet *pkt, int idx, char *mac)
{
    union PFID pfid;
    int ret;

    /* Use port MAC address as the vfid */
    ret = str_to_ether_addr(mac, &pfid.addr);

    if (ret != 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR,
            "Invalid mac address received in JSON\n");
        pkt->vfid[idx] = 0;
        return -1;
    }

    printf("Received MAC Address: %02" PRIx8 ":%02" PRIx8 ":%02" PRIx8 ":"
            "%02" PRIx8 ":%02" PRIx8 ":%02" PRIx8 "\n",
            pfid.addr.addr_bytes[0], pfid.addr.addr_bytes[1],
            pfid.addr.addr_bytes[2], pfid.addr.addr_bytes[3],
            pfid.addr.addr_bytes[4], pfid.addr.addr_bytes[5]);

    pkt->vfid[idx] = pfid.pfid;
    return 0;
}

static char*
get_resource_name_from_chn_path(const char *channel_path)
{
    char *substr = NULL;

    substr = strstr(channel_path, CHANNEL_MGR_FIFO_PATTERN_NAME);

    return substr;
}

static int
get_resource_id_from_vmname(const char *vm_name)
{
    int result = -1;
    int off = 0;

    if (vm_name == NULL)
        return -1;

    while (vm_name[off] != '\0') {
        if (isdigit(vm_name[off]))
            break;
        off++;
    }
    result = atoi(&vm_name[off]);
    if ((result == 0) && (vm_name[off] != '0'))
        return -1;

    return result;
}

static int
parse_json_to_pkt(json_t *element, struct rte_power_channel_packet *pkt,
                    const char *vm_name)
{
    const char *key;
    json_t *value;
    int ret;
    int resource_id;

    memset(pkt, 0, sizeof(*pkt));

    pkt->nb_mac_to_monitor = 0;
    pkt->t_boost_status.tbEnabled = false;
    pkt->workload = RTE_POWER_WL_LOW;
    pkt->policy_to_use = RTE_POWER_POLICY_TIME;
    pkt->command = RTE_POWER_PKT_POLICY;
    pkt->core_type = RTE_POWER_CORE_TYPE_PHYSICAL;

    if (vm_name == NULL) {
        RTE_LOG(ERR, CHANNEL_MONITOR,
            "vm_name is NULL, request rejected !\n");
        return -1;
    }

    json_object_foreach(element, key, value) {
        if (!strcmp(key, "policy")) {
            /* Recurse in to get the contents of profile */
            ret = parse_json_to_pkt(value, pkt, vm_name);
            if (ret)
                return ret;
        } else if (!strcmp(key, "instruction")) {
            /* Recurse in to get the contents of instruction */
            ret = parse_json_to_pkt(value, pkt, vm_name);
            if (ret)
                return ret;
        } else if (!strcmp(key, "command")) {
            char command[32];
            strlcpy(command, json_string_value(value), 32);
            if (!strcmp(command, "power")) {
                pkt->command = RTE_POWER_CPU_POWER;
            } else if (!strcmp(command, "create")) {
                pkt->command = RTE_POWER_PKT_POLICY;
            } else if (!strcmp(command, "destroy")) {
                pkt->command = RTE_POWER_PKT_POLICY_REMOVE;
            } else {
                RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Invalid command received in JSON\n");
                return -1;
            }
        } else if (!strcmp(key, "policy_type")) {
            char command[32];
            strlcpy(command, json_string_value(value), 32);
            if (!strcmp(command, "TIME")) {
                pkt->policy_to_use =
                        RTE_POWER_POLICY_TIME;
            } else if (!strcmp(command, "TRAFFIC")) {
                pkt->policy_to_use =
                        RTE_POWER_POLICY_TRAFFIC;
            } else if (!strcmp(command, "WORKLOAD")) {
                pkt->policy_to_use =
                        RTE_POWER_POLICY_WORKLOAD;
            } else if (!strcmp(command, "BRANCH_RATIO")) {
                pkt->policy_to_use =
                        RTE_POWER_POLICY_BRANCH_RATIO;
            } else {
                RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Wrong policy_type received in JSON\n");
                return -1;
            }
        } else if (!strcmp(key, "workload")) {
            char command[32];
            strlcpy(command, json_string_value(value), 32);
            if (!strcmp(command, "HIGH")) {
                pkt->workload = RTE_POWER_WL_HIGH;
            } else if (!strcmp(command, "MEDIUM")) {
                pkt->workload = RTE_POWER_WL_MEDIUM;
            } else if (!strcmp(command, "LOW")) {
                pkt->workload = RTE_POWER_WL_LOW;
            } else {
                RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Wrong workload received in JSON\n");
                return -1;
            }
        } else if (!strcmp(key, "busy_hours")) {
            unsigned int i;
            size_t size = json_array_size(value);

            for (i = 0; i < size; i++) {
                int hour = (int)json_integer_value(
                        json_array_get(value, i));
                pkt->timer_policy.busy_hours[i] = hour;
            }
        } else if (!strcmp(key, "quiet_hours")) {
            unsigned int i;
            size_t size = json_array_size(value);

            for (i = 0; i < size; i++) {
                int hour = (int)json_integer_value(
                        json_array_get(value, i));
                pkt->timer_policy.quiet_hours[i] = hour;
            }
        } else if (!strcmp(key, "mac_list")) {
            unsigned int i;
            size_t size = json_array_size(value);

            for (i = 0; i < size; i++) {
                char mac[32];
                strlcpy(mac,
                    json_string_value(json_array_get(value, i)),
                    32);
                set_policy_mac(pkt, i, mac);
            }
            pkt->nb_mac_to_monitor = size;
        } else if (!strcmp(key, "avg_packet_thresh")) {
            pkt->traffic_policy.avg_max_packet_thresh =
                    (uint32_t)json_integer_value(value);
        } else if (!strcmp(key, "max_packet_thresh")) {
            pkt->traffic_policy.max_max_packet_thresh =
                    (uint32_t)json_integer_value(value);
        } else if (!strcmp(key, "unit")) {
            char unit[32];
            strlcpy(unit, json_string_value(value), 32);
            if (!strcmp(unit, "SCALE_UP")) {
                pkt->unit = RTE_POWER_SCALE_UP;
            } else if (!strcmp(unit, "SCALE_DOWN")) {
                pkt->unit = RTE_POWER_SCALE_DOWN;
            } else if (!strcmp(unit, "SCALE_MAX")) {
                pkt->unit = RTE_POWER_SCALE_MAX;
            } else if (!strcmp(unit, "SCALE_MIN")) {
                pkt->unit = RTE_POWER_SCALE_MIN;
            } else if (!strcmp(unit, "ENABLE_TURBO")) {
                pkt->unit = RTE_POWER_ENABLE_TURBO;
            } else if (!strcmp(unit, "DISABLE_TURBO")) {
                pkt->unit = RTE_POWER_DISABLE_TURBO;
            } else {
                RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Invalid command received in JSON\n");
                return -1;
            }
        } else {
            RTE_LOG(ERR, CHANNEL_MONITOR,
                "Unknown key received in JSON string: %s\n",
                key);
        }

        resource_id = get_resource_id_from_vmname(vm_name);
        if (resource_id < 0) {
            RTE_LOG(ERR, CHANNEL_MONITOR,
                "Could not get resource_id from vm_name:%s\n",
                vm_name);
            return -1;
        }
        strlcpy(pkt->vm_name, vm_name, RTE_POWER_VM_MAX_NAME_SZ);
        pkt->resource_id = resource_id;
    }
    return 0;
}
#endif

void channel_monitor_exit(void)
{
    run_loop = 0;
    rte_free(global_events_list);
}

static void
core_share(int pNo, int z, int x, int t)
{
    if (policies[pNo].core_share[z].pcpu == lvm_info[x].pcpus[t]) {
        if (strcmp(policies[pNo].pkt.vm_name,
                lvm_info[x].vm_name) != 0) {
            policies[pNo].core_share[z].status = 1;
            power_manager_scale_core_max(
                    policies[pNo].core_share[z].pcpu);
        }
    }
}

static void
core_share_status(int pNo)
{

    int noVms = 0, noVcpus = 0, z, x, t;

    get_all_vm(&noVms, &noVcpus);

    /* Reset Core Share Status. */
    for (z = 0; z < noVcpus; z++)
        policies[pNo].core_share[z].status = 0;

    /* Foreach vcpu in a policy. */
    for (z = 0; z < policies[pNo].pkt.num_vcpu; z++) {
        /* Foreach VM on the platform. */
        for (x = 0; x < noVms; x++) {
            /* Foreach vcpu of VMs on platform. */
            for (t = 0; t < lvm_info[x].num_cpus; t++)
                core_share(pNo, z, x, t);
        }
    }
}


static int
pcpu_monitor(struct policy *pol, struct core_info *ci, int pcpu, int count)
{
    int ret = 0;

    if (pol->pkt.policy_to_use == RTE_POWER_POLICY_BRANCH_RATIO) {
        ci->cd[pcpu].oob_enabled = 1;
        ret = add_core_to_monitor(pcpu);
        if (ret == 0)
            RTE_LOG(INFO, CHANNEL_MONITOR,
                    "Monitoring pcpu %d OOB for %s\n",
                    pcpu, pol->pkt.vm_name);
        else
            RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Error monitoring pcpu %d OOB for %s\n",
                    pcpu, pol->pkt.vm_name);

    } else {
        pol->core_share[count].pcpu = pcpu;
        RTE_LOG(INFO, CHANNEL_MONITOR,
                "Monitoring pcpu %d for %s\n",
                pcpu, pol->pkt.vm_name);
    }
    return ret;
}

static void
get_pcpu_to_control(struct policy *pol)
{

    /* Convert vcpu to pcpu. */
    struct vm_info info;
    int pcpu, count;
    struct core_info *ci;

    ci = get_core_info();

    RTE_LOG(DEBUG, CHANNEL_MONITOR,
            "Looking for pcpu for %s\n", pol->pkt.vm_name);

    /*
     * So now that we're handling virtual and physical cores, we need to
     * differenciate between them when adding them to the branch monitor.
     * Virtual cores need to be converted to physical cores.
     */
    if (pol->pkt.core_type == RTE_POWER_CORE_TYPE_VIRTUAL) {
        /*
         * If the cores in the policy are virtual, we need to map them
         * to physical core. We look up the vm info and use that for
         * the mapping.
         */
        get_info_vm(pol->pkt.vm_name, &info);
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            pcpu = info.pcpu_map[pol->pkt.vcpu_to_control[count]];
            pcpu_monitor(pol, ci, pcpu, count);
        }
    } else {
        /*
         * If the cores in the policy are physical, we just use
         * those core id's directly.
         */
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            pcpu = pol->pkt.vcpu_to_control[count];
            pcpu_monitor(pol, ci, pcpu, count);
        }
    }
}

static int
get_pfid(struct policy *pol)
{

    int i, x, ret = 0;

    for (i = 0; i < pol->pkt.nb_mac_to_monitor; i++) {

        RTE_ETH_FOREACH_DEV(x) {
#ifdef RTE_LIBRTE_I40E_PMD
            ret = rte_pmd_i40e_query_vfid_by_mac(x,
                (struct rte_ether_addr *)&(pol->pkt.vfid[i]));
#else
            ret = -ENOTSUP;
#endif
            if (ret != -EINVAL) {
                pol->port[i] = x;
                break;
            }
        }
        if (ret == -EINVAL || ret == -ENOTSUP || ret == ENODEV) {
            RTE_LOG(INFO, CHANNEL_MONITOR,
                "Error with Policy. MAC not found on "
                "attached ports ");
            pol->enabled = 0;
            return ret;
        }
        pol->pfid[i] = ret;
    }
    return 1;
}

static int
update_policy(struct rte_power_channel_packet *pkt)
{

    unsigned int updated = 0;
    unsigned int i;


    RTE_LOG(INFO, CHANNEL_MONITOR,
            "Applying policy for %s\n", pkt->vm_name);

    for (i = 0; i < RTE_DIM(policies); i++) {
        if (strcmp(policies[i].pkt.vm_name, pkt->vm_name) == 0) {
            /* Copy the contents of *pkt into the policy.pkt */
            policies[i].pkt = *pkt;
            get_pcpu_to_control(&policies[i]);
            /* Check Eth dev only for Traffic policy */
            if (policies[i].pkt.policy_to_use ==
                    RTE_POWER_POLICY_TRAFFIC) {
                if (get_pfid(&policies[i]) < 0) {
                    updated = 1;
                    break;
                }
            }
            core_share_status(i);
            policies[i].enabled = 1;
            updated = 1;
        }
    }
    if (!updated) {
        for (i = 0; i < RTE_DIM(policies); i++) {
            if (policies[i].enabled == 0) {
                policies[i].pkt = *pkt;
                get_pcpu_to_control(&policies[i]);
                /* Check Eth dev only for Traffic policy */
                if (policies[i].pkt.policy_to_use ==
                        RTE_POWER_POLICY_TRAFFIC) {
                    if (get_pfid(&policies[i]) < 0) {
                        updated = 1;
                        break;
                    }
                }
                core_share_status(i);
                policies[i].enabled = 1;
                break;
            }
        }
    }
    return 0;
}

static int
remove_policy(struct rte_power_channel_packet *pkt __rte_unused)
{
    unsigned int i;

    /*
     * Disabling the policy is simply a case of setting
     * enabled to 0
     */
    for (i = 0; i < RTE_DIM(policies); i++) {
        if (strcmp(policies[i].pkt.vm_name, pkt->vm_name) == 0) {
            policies[i].enabled = 0;
            return 0;
        }
    }
    return -1;
}

static uint64_t
get_pkt_diff(struct policy *pol)
{

    uint64_t vsi_pkt_count,
        vsi_pkt_total = 0,
        vsi_pkt_count_prev_total = 0;
    double rdtsc_curr, rdtsc_diff, diff;
    int x;
#ifdef RTE_LIBRTE_I40E_PMD
    struct rte_eth_stats vf_stats;
#endif

    for (x = 0; x < pol->pkt.nb_mac_to_monitor; x++) {

#ifdef RTE_LIBRTE_I40E_PMD
        /*Read vsi stats*/
        if (rte_pmd_i40e_get_vf_stats(x, pol->pfid[x], &vf_stats) == 0)
            vsi_pkt_count = vf_stats.ipackets;
        else
            vsi_pkt_count = -1;
#else
        vsi_pkt_count = -1;
#endif

        vsi_pkt_total += vsi_pkt_count;

        vsi_pkt_count_prev_total += vsi_pkt_count_prev[pol->pfid[x]];
        vsi_pkt_count_prev[pol->pfid[x]] = vsi_pkt_count;
    }

    rdtsc_curr = rte_rdtsc_precise();
    rdtsc_diff = rdtsc_curr - rdtsc_prev[pol->pfid[x-1]];
    rdtsc_prev[pol->pfid[x-1]] = rdtsc_curr;

    diff = (vsi_pkt_total - vsi_pkt_count_prev_total) *
            ((double)rte_get_tsc_hz() / rdtsc_diff);

    return diff;
}

static void
apply_traffic_profile(struct policy *pol)
{

    int count;
    uint64_t diff = 0;

    diff = get_pkt_diff(pol);

    if (diff >= (pol->pkt.traffic_policy.max_max_packet_thresh)) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_max(
                        pol->core_share[count].pcpu);
        }
    } else if (diff >= (pol->pkt.traffic_policy.avg_max_packet_thresh)) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_med(
                        pol->core_share[count].pcpu);
        }
    } else if (diff < (pol->pkt.traffic_policy.avg_max_packet_thresh)) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_min(
                        pol->core_share[count].pcpu);
        }
    }
}

static void
apply_time_profile(struct policy *pol)
{

    int count, x;
    struct timeval tv;
    struct tm *ptm;
    char time_string[40];

    /* Obtain the time of day, and convert it to a tm struct. */
    gettimeofday(&tv, NULL);
    ptm = localtime(&tv.tv_sec);
    /* Format the date and time, down to a single second. */
    strftime(time_string, sizeof(time_string), "%Y-%m-%d %H:%M:%S", ptm);

    for (x = 0; x < RTE_POWER_HOURS_PER_DAY; x++) {

        if (ptm->tm_hour == pol->pkt.timer_policy.busy_hours[x]) {
            for (count = 0; count < pol->pkt.num_vcpu; count++) {
                if (pol->core_share[count].status != 1) {
                    power_manager_scale_core_max(
                        pol->core_share[count].pcpu);
                }
            }
            break;
        } else if (ptm->tm_hour ==
                pol->pkt.timer_policy.quiet_hours[x]) {
            for (count = 0; count < pol->pkt.num_vcpu; count++) {
                if (pol->core_share[count].status != 1) {
                    power_manager_scale_core_min(
                        pol->core_share[count].pcpu);
            }
        }
            break;
        } else if (ptm->tm_hour ==
            pol->pkt.timer_policy.hours_to_use_traffic_profile[x]) {
            apply_traffic_profile(pol);
            break;
        }
    }
}

static void
apply_workload_profile(struct policy *pol)
{

    int count;

    if (pol->pkt.workload == RTE_POWER_WL_HIGH) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_max(
                        pol->core_share[count].pcpu);
        }
    } else if (pol->pkt.workload == RTE_POWER_WL_MEDIUM) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_med(
                        pol->core_share[count].pcpu);
        }
    } else if (pol->pkt.workload == RTE_POWER_WL_LOW) {
        for (count = 0; count < pol->pkt.num_vcpu; count++) {
            if (pol->core_share[count].status != 1)
                power_manager_scale_core_min(
                        pol->core_share[count].pcpu);
        }
    }
}

static void
apply_policy(struct policy *pol)
{

    struct rte_power_channel_packet *pkt = &pol->pkt;

    /*Check policy to use*/
    if (pkt->policy_to_use == RTE_POWER_POLICY_TRAFFIC)
        apply_traffic_profile(pol);
    else if (pkt->policy_to_use == RTE_POWER_POLICY_TIME)
        apply_time_profile(pol);
    else if (pkt->policy_to_use == RTE_POWER_POLICY_WORKLOAD)
        apply_workload_profile(pol);
}

static int
write_binary_packet(void *buffer,
        size_t buffer_len,
        struct channel_info *chan_info)
{
    int ret;

    if (buffer_len == 0 || buffer == NULL)
        return -1;

    if (chan_info->fd < 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Channel is not connected\n");
        return -1;
    }

    while (buffer_len > 0) {
        ret = write(chan_info->fd, buffer, buffer_len);
        if (ret == -1) {
            if (errno == EINTR)
                continue;
            RTE_LOG(ERR, CHANNEL_MONITOR, "Write function failed due to %s.\n",
                    strerror(errno));
            return -1;
        }
        buffer = (char *)buffer + ret;
        buffer_len -= ret;
    }
    return 0;
}

static int
send_freq(struct rte_power_channel_packet *pkt,
        struct channel_info *chan_info,
        bool freq_list)
{
    unsigned int vcore_id = pkt->resource_id;
    struct rte_power_channel_packet_freq_list channel_pkt_freq_list;
    struct vm_info info;

    if (get_info_vm(pkt->vm_name, &info) != 0)
        return -1;

    if (!freq_list && vcore_id >= RTE_POWER_MAX_VCPU_PER_VM)
        return -1;

    if (!info.allow_query)
        return -1;

    channel_pkt_freq_list.command = RTE_POWER_FREQ_LIST;
    channel_pkt_freq_list.num_vcpu = info.num_vcpus;

    if (freq_list) {
        unsigned int i;
        for (i = 0; i < info.num_vcpus; i++)
            channel_pkt_freq_list.freq_list[i] =
              power_manager_get_current_frequency(info.pcpu_map[i]);
    } else {
        channel_pkt_freq_list.freq_list[vcore_id] =
          power_manager_get_current_frequency(info.pcpu_map[vcore_id]);
    }

    return write_binary_packet(&channel_pkt_freq_list,
            sizeof(channel_pkt_freq_list),
            chan_info);
}

static int
send_capabilities(struct rte_power_channel_packet *pkt,
        struct channel_info *chan_info,
        bool list_requested)
{
    unsigned int vcore_id = pkt->resource_id;
    struct rte_power_channel_packet_caps_list channel_pkt_caps_list;
    struct vm_info info;
    struct rte_power_core_capabilities caps;
    int ret;

    if (get_info_vm(pkt->vm_name, &info) != 0)
        return -1;

    if (!list_requested && vcore_id >= RTE_POWER_MAX_VCPU_PER_VM)
        return -1;

    if (!info.allow_query)
        return -1;

    channel_pkt_caps_list.command = RTE_POWER_CAPS_LIST;
    channel_pkt_caps_list.num_vcpu = info.num_vcpus;

    if (list_requested) {
        unsigned int i;
        for (i = 0; i < info.num_vcpus; i++) {
            ret = rte_power_get_capabilities(info.pcpu_map[i],
                    &caps);
            if (ret == 0) {
                channel_pkt_caps_list.turbo[i] =
                        caps.turbo;
                channel_pkt_caps_list.priority[i] =
                        caps.priority;
            } else
                return -1;

        }
    } else {
        ret = rte_power_get_capabilities(info.pcpu_map[vcore_id],
                &caps);
        if (ret == 0) {
            channel_pkt_caps_list.turbo[vcore_id] =
                    caps.turbo;
            channel_pkt_caps_list.priority[vcore_id] =
                    caps.priority;
        } else
            return -1;
    }

    return write_binary_packet(&channel_pkt_caps_list,
            sizeof(channel_pkt_caps_list),
            chan_info);
}

static int
send_ack_for_received_cmd(struct rte_power_channel_packet *pkt,
        struct channel_info *chan_info,
        uint32_t command)
{
    pkt->command = command;
    return write_binary_packet(pkt,
            sizeof(*pkt),
            chan_info);
}

static int
process_request(struct rte_power_channel_packet *pkt,
        struct channel_info *chan_info)
{
    int ret;

    if (chan_info == NULL)
        return -1;

    if (rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_CONNECTED,
            CHANNEL_MGR_CHANNEL_PROCESSING) == 0)
        return -1;

    if (pkt->command == RTE_POWER_CPU_POWER) {
        unsigned int core_num;

        if (pkt->core_type == RTE_POWER_CORE_TYPE_VIRTUAL)
            core_num = get_pcpu(chan_info, pkt->resource_id);
        else
            core_num = pkt->resource_id;

        RTE_LOG(DEBUG, CHANNEL_MONITOR, "Processing requested cmd for cpu:%d\n",
            core_num);

        int scale_res;
        bool valid_unit = true;

        switch (pkt->unit) {
        case(RTE_POWER_SCALE_MIN):
            scale_res = power_manager_scale_core_min(core_num);
            break;
        case(RTE_POWER_SCALE_MAX):
            scale_res = power_manager_scale_core_max(core_num);
            break;
        case(RTE_POWER_SCALE_DOWN):
            scale_res = power_manager_scale_core_down(core_num);
            break;
        case(RTE_POWER_SCALE_UP):
            scale_res = power_manager_scale_core_up(core_num);
            break;
        case(RTE_POWER_ENABLE_TURBO):
            scale_res = power_manager_enable_turbo_core(core_num);
            break;
        case(RTE_POWER_DISABLE_TURBO):
            scale_res = power_manager_disable_turbo_core(core_num);
            break;
        default:
            valid_unit = false;
            break;
        }

        if (valid_unit) {
            ret = send_ack_for_received_cmd(pkt,
                    chan_info,
                    scale_res >= 0 ?
                        RTE_POWER_CMD_ACK :
                        RTE_POWER_CMD_NACK);
            if (ret < 0)
                RTE_LOG(ERR, CHANNEL_MONITOR, "Error during sending ack command.\n");
        } else
            RTE_LOG(ERR, CHANNEL_MONITOR, "Unexpected unit type.\n");

    }

    if (pkt->command == RTE_POWER_PKT_POLICY) {
        RTE_LOG(INFO, CHANNEL_MONITOR, "Processing policy request %s\n",
                pkt->vm_name);
        int ret = send_ack_for_received_cmd(pkt,
                chan_info,
                RTE_POWER_CMD_ACK);
        if (ret < 0)
            RTE_LOG(ERR, CHANNEL_MONITOR, "Error during sending ack command.\n");
        update_policy(pkt);
        policy_is_set = 1;
    }

    if (pkt->command == RTE_POWER_PKT_POLICY_REMOVE) {
        ret = remove_policy(pkt);
        if (ret == 0)
            RTE_LOG(INFO, CHANNEL_MONITOR,
                 "Removed policy %s\n", pkt->vm_name);
        else
            RTE_LOG(INFO, CHANNEL_MONITOR,
                 "Policy %s does not exist\n", pkt->vm_name);
    }

    if (pkt->command == RTE_POWER_QUERY_FREQ_LIST ||
        pkt->command == RTE_POWER_QUERY_FREQ) {

        RTE_LOG(INFO, CHANNEL_MONITOR,
            "Frequency for %s requested.\n", pkt->vm_name);
        int ret = send_freq(pkt,
                chan_info,
                pkt->command == RTE_POWER_QUERY_FREQ_LIST);
        if (ret < 0)
            RTE_LOG(ERR, CHANNEL_MONITOR, "Error during frequency sending.\n");
    }

    if (pkt->command == RTE_POWER_QUERY_CAPS_LIST ||
        pkt->command == RTE_POWER_QUERY_CAPS) {

        RTE_LOG(INFO, CHANNEL_MONITOR,
            "Capabilities for %s requested.\n", pkt->vm_name);
        int ret = send_capabilities(pkt,
                chan_info,
                pkt->command == RTE_POWER_QUERY_CAPS_LIST);
        if (ret < 0)
            RTE_LOG(ERR, CHANNEL_MONITOR, "Error during sending capabilities.\n");
    }

    /*
     * Return is not checked as channel status may have been set to DISABLED
     * from management thread
     */
    rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_PROCESSING,
            CHANNEL_MGR_CHANNEL_CONNECTED);
    return 0;

}

int
add_channel_to_monitor(struct channel_info **chan_info)
{
    struct channel_info *info = *chan_info;
    struct epoll_event event;

    event.events = EPOLLIN;
    event.data.ptr = info;
    if (epoll_ctl(global_event_fd, EPOLL_CTL_ADD, info->fd, &event) < 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to add channel '%s' "
                "to epoll\n", info->channel_path);
        return -1;
    }
    RTE_LOG(ERR, CHANNEL_MONITOR, "Added channel '%s' "
            "to monitor\n", info->channel_path);
    return 0;
}

int
remove_channel_from_monitor(struct channel_info *chan_info)
{
    if (epoll_ctl(global_event_fd, EPOLL_CTL_DEL,
            chan_info->fd, NULL) < 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to remove channel '%s' "
                "from epoll\n", chan_info->channel_path);
        return -1;
    }
    return 0;
}

int
channel_monitor_init(void)
{
    global_event_fd = epoll_create1(0);
    if (global_event_fd == 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR,
                "Error creating epoll context with error %s\n",
                strerror(errno));
        return -1;
    }
    global_events_list = rte_malloc("epoll_events",
            sizeof(*global_events_list)
            * MAX_EVENTS, RTE_CACHE_LINE_SIZE);
    if (global_events_list == NULL) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to rte_malloc for "
                "epoll events\n");
        return -1;
    }
    return 0;
}

static void
read_binary_packet(struct channel_info *chan_info)
{
    struct rte_power_channel_packet pkt;
    void *buffer = &pkt;
    int buffer_len = sizeof(pkt);
    int n_bytes, err = 0;

    while (buffer_len > 0) {
        n_bytes = read(chan_info->fd,
                buffer, buffer_len);
        if (n_bytes == buffer_len)
            break;
        if (n_bytes < 0) {
            err = errno;
            RTE_LOG(DEBUG, CHANNEL_MONITOR,
                "Received error on "
                "channel '%s' read: %s\n",
                chan_info->channel_path,
                strerror(err));
            remove_channel(&chan_info);
            break;
        }
        buffer = (char *)buffer + n_bytes;
        buffer_len -= n_bytes;
    }
    if (!err)
        process_request(&pkt, chan_info);
}

#ifdef USE_JANSSON
static void
read_json_packet(struct channel_info *chan_info)
{
    struct rte_power_channel_packet pkt;
    int n_bytes, ret;
    json_t *root;
    json_error_t error;
    const char *resource_name;
    char *start, *end;
    uint32_t n;


    /* read opening brace to closing brace */
    do {
        int idx = 0;
        int indent = 0;
        do {
            n_bytes = read(chan_info->fd, &json_data[idx], 1);
            if (n_bytes == 0)
                break;
            if (json_data[idx] == '{')
                indent++;
            if (json_data[idx] == '}')
                indent--;
            if ((indent > 0) || (idx > 0))
                idx++;
            if (indent <= 0)
                json_data[idx] = 0;
            if (idx >= MAX_JSON_STRING_LEN-1)
                break;
        } while (indent > 0);

        json_data[idx] = '\0';

        if (strlen(json_data) == 0)
            continue;

        printf("got [%s]\n", json_data);

        root = json_loads(json_data, 0, &error);

        if (root) {
            resource_name = get_resource_name_from_chn_path(
                chan_info->channel_path);
            /*
             * Because our data is now in the json
             * object, we can overwrite the pkt
             * with a rte_power_channel_packet struct, using
             * parse_json_to_pkt()
             */
            ret = parse_json_to_pkt(root, &pkt, resource_name);
            json_decref(root);
            if (ret) {
                RTE_LOG(ERR, CHANNEL_MONITOR,
                    "Error validating JSON profile data\n");
                break;
            }
            start = strstr(pkt.vm_name,
                    CHANNEL_MGR_FIFO_PATTERN_NAME);
            if (start != NULL) {
                /* move past pattern to start of fifo id */
                start += strlen(CHANNEL_MGR_FIFO_PATTERN_NAME);

                end = start;
                n = (uint32_t)strtoul(start, &end, 10);

                if (end[0] == '\0') {
                    /* Add core id to core list */
                    pkt.num_vcpu = 1;
                    pkt.vcpu_to_control[0] = n;
                    process_request(&pkt, chan_info);
                } else {
                    RTE_LOG(ERR, CHANNEL_MONITOR,
                        "Cannot extract core id from fifo name\n");
                }
            } else {
                process_request(&pkt, chan_info);
            }
        } else {
            RTE_LOG(ERR, CHANNEL_MONITOR,
                    "JSON error on line %d: %s\n",
                    error.line, error.text);
        }
    } while (n_bytes > 0);
}
#endif

void
run_channel_monitor(void)
{
    while (run_loop) {
        int n_events, i;

        n_events = epoll_wait(global_event_fd, global_events_list,
                MAX_EVENTS, 1);
        if (!run_loop)
            break;
        for (i = 0; i < n_events; i++) {
            struct channel_info *chan_info = (struct channel_info *)
                    global_events_list[i].data.ptr;
            if ((global_events_list[i].events & EPOLLERR) ||
                (global_events_list[i].events & EPOLLHUP)) {
                RTE_LOG(INFO, CHANNEL_MONITOR,
                        "Remote closed connection for "
                        "channel '%s'\n",
                        chan_info->channel_path);
                remove_channel(&chan_info);
                continue;
            }
            if (global_events_list[i].events & EPOLLIN) {

                switch (chan_info->type) {
                case CHANNEL_TYPE_BINARY:
                    read_binary_packet(chan_info);
                    break;
#ifdef USE_JANSSON
                case CHANNEL_TYPE_JSON:
                    read_json_packet(chan_info);
                    break;
#endif
                default:
                    break;
                }
            }
        }
        rte_delay_us(time_period_ms*1000);
        if (policy_is_set) {
            unsigned int j;

            for (j = 0; j < RTE_DIM(policies); j++) {
                if (policies[j].enabled == 1)
                    apply_policy(&policies[j]);
            }
        }
    }
}