sys/dev/cpuctl/cpuctl.c

root/sys/dev/cpuctl/cpuctl.c
/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2006-2008 Stanislav Sedov <stas@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/sched.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/pcpu.h>
#include <sys/smp.h>
#include <sys/pmckern.h>
#include <sys/cpuctl.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>

#include <machine/cpufunc.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#include <x86/ucode.h>

static d_open_t cpuctl_open;
static d_ioctl_t cpuctl_ioctl;

#define CPUCTL_VERSION 1

#ifdef CPUCTL_DEBUG
# define        DPRINTF(format,...) printf(format, __VA_ARGS__);
#else
# define        DPRINTF(...)
#endif

#define UCODE_SIZE_MAX  (4 * 1024 * 1024)

static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
    struct thread *td);
static int cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
    struct thread *td);
static int cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
    struct thread *td);
static int cpuctl_do_eval_cpu_features(int cpu, struct thread *td);
static int cpuctl_do_update(int cpu, cpuctl_update_args_t *data,
    struct thread *td);
static int update_intel(int cpu, cpuctl_update_args_t *args,
    struct thread *td);
static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
static int update_via(int cpu, cpuctl_update_args_t *args,
    struct thread *td);

static struct cdev **cpuctl_devs;
static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");

static struct cdevsw cpuctl_cdevsw = {
        .d_version =    D_VERSION,
        .d_open =       cpuctl_open,
        .d_ioctl =      cpuctl_ioctl,
        .d_name =       "cpuctl",
};

/*
 * This function checks if specified cpu enabled or not.
 */
static int
cpu_enabled(int cpu)
{

        return (pmc_cpu_is_disabled(cpu) == 0);
}

/*
 * Check if the current thread is bound to a specific cpu.
 */
static int
cpu_sched_is_bound(struct thread *td)
{
        int ret;

        thread_lock(td);
        ret = sched_is_bound(td);
        thread_unlock(td);
        return (ret);
}

/*
 * Switch to target cpu to run.
 */
static void
set_cpu(int cpu, struct thread *td)
{

        KASSERT(cpu >= 0 && cpu <= mp_maxid && cpu_enabled(cpu),
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
        thread_lock(td);
        sched_bind(td, cpu);
        thread_unlock(td);
        KASSERT(td->td_oncpu == cpu,
            ("[cpuctl,%d]: cannot bind to target cpu %d on cpu %d", __LINE__,
            cpu, td->td_oncpu));
}

static void
restore_cpu(int oldcpu, int is_bound, struct thread *td)
{

        KASSERT(oldcpu >= 0 && oldcpu <= mp_maxid && cpu_enabled(oldcpu),
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
        thread_lock(td);
        if (is_bound == 0)
                sched_unbind(td);
        else
                sched_bind(td, oldcpu);
        thread_unlock(td);
}

int
cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
    int flags, struct thread *td)
{
        int cpu, ret;

        cpu = dev2unit(dev);
        if (cpu > mp_maxid || !cpu_enabled(cpu)) {
                DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
                return (ENXIO);
        }
        /* Require write flag for "write" requests. */
        if ((cmd == CPUCTL_MSRCBIT || cmd == CPUCTL_MSRSBIT ||
            cmd == CPUCTL_UPDATE || cmd == CPUCTL_WRMSR ||
            cmd == CPUCTL_EVAL_CPU_FEATURES) &&
            (flags & FWRITE) == 0)
                return (EPERM);
        switch (cmd) {
        case CPUCTL_RDMSR:
                ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
                break;
        case CPUCTL_MSRSBIT:
        case CPUCTL_MSRCBIT:
        case CPUCTL_WRMSR:
                ret = priv_check(td, PRIV_CPUCTL_WRMSR);
                if (ret != 0)
                        goto fail;
                ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
                break;
        case CPUCTL_CPUID:
                ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
                break;
        case CPUCTL_UPDATE:
                ret = priv_check(td, PRIV_CPUCTL_UPDATE);
                if (ret != 0)
                        goto fail;
                ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
                break;
        case CPUCTL_CPUID_COUNT:
                ret = cpuctl_do_cpuid_count(cpu,
                    (cpuctl_cpuid_count_args_t *)data, td);
                break;
        case CPUCTL_EVAL_CPU_FEATURES:
                ret = cpuctl_do_eval_cpu_features(cpu, td);
                break;
        default:
                ret = EINVAL;
                break;
        }
fail:
        return (ret);
}

/*
 * Actually perform cpuid operation.
 */
static int
cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
    struct thread *td)
{
        int is_bound = 0;
        int oldcpu;

        KASSERT(cpu >= 0 && cpu <= mp_maxid,
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));

        /* Explicitly clear cpuid data to avoid returning stale info. */
        bzero(data->data, sizeof(data->data));
        DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
            __LINE__, data->level, data->level_type, cpu);
#ifdef __i386__
        if (cpu_id == 0)
                return (ENODEV);
#endif
        oldcpu = td->td_oncpu;
        is_bound = cpu_sched_is_bound(td);
        set_cpu(cpu, td);
        cpuid_count(data->level, data->level_type, data->data);
        restore_cpu(oldcpu, is_bound, td);
        return (0);
}

static int
cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
{
        cpuctl_cpuid_count_args_t cdata;
        int error;

        cdata.level = data->level;
        /* Override the level type. */
        cdata.level_type = 0;
        error = cpuctl_do_cpuid_count(cpu, &cdata, td);
        bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
        return (error);
}

/*
 * Actually perform MSR operations.
 */
static int
cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
{
        uint64_t reg;
        int is_bound = 0;
        int oldcpu;
        int ret;

        KASSERT(cpu >= 0 && cpu <= mp_maxid,
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));

        /*
         * Explicitly clear cpuid data to avoid returning stale
         * info
         */
        DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
            data->msr, cpu);
#ifdef __i386__
        if ((cpu_feature & CPUID_MSR) == 0)
                return (ENODEV);
#endif
        oldcpu = td->td_oncpu;
        is_bound = cpu_sched_is_bound(td);
        set_cpu(cpu, td);
        if (cmd == CPUCTL_RDMSR) {
                data->data = 0;
                ret = rdmsr_safe(data->msr, &data->data);
        } else if (cmd == CPUCTL_WRMSR) {
                ret = wrmsr_safe(data->msr, data->data);
        } else if (cmd == CPUCTL_MSRSBIT) {
                critical_enter();
                ret = rdmsr_safe(data->msr, &reg);
                if (ret == 0)
                        ret = wrmsr_safe(data->msr, reg | data->data);
                critical_exit();
        } else if (cmd == CPUCTL_MSRCBIT) {
                critical_enter();
                ret = rdmsr_safe(data->msr, &reg);
                if (ret == 0)
                        ret = wrmsr_safe(data->msr, reg & ~data->data);
                critical_exit();
        } else
                panic("[cpuctl,%d]: unknown operation requested: %lu",
                    __LINE__, cmd);
        restore_cpu(oldcpu, is_bound, td);
        return (ret);
}

/*
 * Actually perform microcode update.
 */
static int
cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
{
        cpuctl_cpuid_args_t args = {
                .level = 0,
        };
        char vendor[13];
        int ret;

        KASSERT(cpu >= 0 && cpu <= mp_maxid,
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
        DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);

        ret = cpuctl_do_cpuid(cpu, &args, td);
        if (ret != 0)
                return (ret);
        ((uint32_t *)vendor)[0] = args.data[1];
        ((uint32_t *)vendor)[1] = args.data[3];
        ((uint32_t *)vendor)[2] = args.data[2];
        vendor[12] = '\0';
        if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
                ret = update_intel(cpu, data, td);
        else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
                ret = update_amd(cpu, data, td);
        else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID))
            == 0)
                ret = update_via(cpu, data, td);
        else
                ret = ENXIO;
        return (ret);
}

struct ucode_update_data {
        void *ptr;
        int cpu;
        int ret;
};

static void
ucode_intel_load_rv(void *arg)
{
        struct ucode_update_data *d;

        d = arg;
        if (PCPU_GET(cpuid) == d->cpu)
                d->ret = ucode_intel_load(d->ptr, SAFE, NULL, NULL);
}

static int
update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
{
        struct ucode_update_data d;
        void *ptr;
        int is_bound, oldcpu, ret;

        if (args->size == 0 || args->data == NULL) {
                DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
                return (EINVAL);
        }
        if (args->size > UCODE_SIZE_MAX) {
                DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
                return (EINVAL);
        }

        /*
         * 16 byte alignment required.  Rely on the fact that
         * malloc(9) always returns the pointer aligned at least on
         * the size of the allocation.
         */
        ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
        if (copyin(args->data, ptr, args->size) != 0) {
                DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
                    __LINE__, args->data, ptr, args->size);
                ret = EFAULT;
                goto out;
        }
        oldcpu = td->td_oncpu;
        is_bound = cpu_sched_is_bound(td);
        set_cpu(cpu, td);
        d.ptr = ptr;
        d.cpu = cpu;
        smp_rendezvous(NULL, ucode_intel_load_rv, NULL, &d);
        restore_cpu(oldcpu, is_bound, td);
        ret = d.ret;

        /*
         * Replace any existing update.  This ensures that the new update
         * will be reloaded automatically during ACPI resume.
         */
        if (ret == 0)
                ptr = ucode_update(ptr);

out:
        free(ptr, M_CPUCTL);
        return (ret);
}

/*
 * NB: MSR 0xc0010020, MSR_K8_UCODE_UPDATE, is not documented by AMD.
 * Coreboot, illumos and Linux source code was used to understand
 * its workings.
 */
static void
amd_ucode_wrmsr(void *arg)
{
        struct ucode_update_data *d = arg;
        uint32_t tmp[4];

        if (PCPU_GET(cpuid) == d->cpu)
                d->ret = wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)d->ptr);
        do_cpuid(0, tmp);
}

static int
update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
{
        struct ucode_update_data d = { .cpu = cpu };

        if (args->size == 0 || args->data == NULL) {
                DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
                return (EINVAL);
        }
        if (args->size > UCODE_SIZE_MAX) {
                DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
                return (EINVAL);
        }

        /*
         * 16 byte alignment required.  Rely on the fact that
         * malloc(9) always returns the pointer aligned at least on
         * the size of the allocation.
         */
        d.ptr = malloc(args->size + 16, M_CPUCTL, M_ZERO | M_WAITOK);
        if (copyin(args->data, d.ptr, args->size) != 0) {
                DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
                    __LINE__, args->data, ptr, args->size);
                d.ret = EFAULT;
                goto fail;
        }
        smp_rendezvous(NULL, amd_ucode_wrmsr, NULL, &d);
fail:
        free(d.ptr, M_CPUCTL);
        return (d.ret);
}

static int
update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
{
        void *ptr;
        uint64_t rev0, rev1, res;
        uint32_t tmp[4];
        int is_bound;
        int oldcpu;
        int ret;

        if (args->size == 0 || args->data == NULL) {
                DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
                return (EINVAL);
        }
        if (args->size > UCODE_SIZE_MAX) {
                DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
                return (EINVAL);
        }

        /*
         * 4 byte alignment required.
         */
        ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
        if (copyin(args->data, ptr, args->size) != 0) {
                DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
                    __LINE__, args->data, ptr, args->size);
                ret = EFAULT;
                goto fail;
        }
        oldcpu = td->td_oncpu;
        is_bound = cpu_sched_is_bound(td);
        set_cpu(cpu, td);
        critical_enter();
        rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */

        /*
         * Perform update.
         */
        wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
        do_cpuid(1, tmp);

        /*
         * Result are in low byte of MSR FCR5:
         * 0x00: No update has been attempted since RESET.
         * 0x01: The last attempted update was successful.
         * 0x02: The last attempted update was unsuccessful due to a bad
         *       environment. No update was loaded and any preexisting
         *       patches are still active.
         * 0x03: The last attempted update was not applicable to this processor.
         *       No update was loaded and any preexisting patches are still
         *       active.
         * 0x04: The last attempted update was not successful due to an invalid
         *       update data block. No update was loaded and any preexisting
         *       patches are still active
         */
        rdmsr_safe(0x1205, &res);
        res &= 0xff;
        critical_exit();
        rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
        restore_cpu(oldcpu, is_bound, td);

        DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
            (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);

        if (res != 0x01)
                ret = EINVAL;
        else
                ret = 0;
fail:
        free(ptr, M_CPUCTL);
        return (ret);
}

static int
cpuctl_do_eval_cpu_features(int cpu, struct thread *td)
{
        int is_bound = 0;
        int oldcpu;

        KASSERT(cpu >= 0 && cpu <= mp_maxid,
            ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));

#ifdef __i386__
        if (cpu_id == 0)
                return (ENODEV);
#endif
        oldcpu = td->td_oncpu;
        is_bound = cpu_sched_is_bound(td);
        set_cpu(cpu, td);
        identify_cpu1();
        identify_cpu2();
        restore_cpu(oldcpu, is_bound, td);
        hw_ibrs_recalculate(true);
        hw_ssb_recalculate(true);
#ifdef __amd64__
        amd64_syscall_ret_flush_l1d_recalc();
        pmap_allow_2m_x_ept_recalculate();
#endif
        hw_mds_recalculate();
        x86_taa_recalculate();
        x86_rngds_mitg_recalculate(true);
        zenbleed_check_and_apply(true);
        printcpuinfo();
        return (0);
}

int
cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
{
        int ret = 0;
        int cpu;

        cpu = dev2unit(dev);
        if (cpu > mp_maxid || !cpu_enabled(cpu)) {
                DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
                    cpu);
                return (ENXIO);
        }
        if (flags & FWRITE)
                ret = securelevel_gt(td->td_ucred, 0);
        return (ret);
}

static int
cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
{
        int cpu;

        switch(type) {
        case MOD_LOAD:
                if (bootverbose)
                        printf("cpuctl: access to MSR registers/cpuid info.\n");
                cpuctl_devs = malloc(sizeof(*cpuctl_devs) * (mp_maxid + 1), M_CPUCTL,
                    M_WAITOK | M_ZERO);
                CPU_FOREACH(cpu)
                        if (cpu_enabled(cpu))
                                cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
                                    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
                break;
        case MOD_UNLOAD:
                CPU_FOREACH(cpu) {
                        if (cpuctl_devs[cpu] != NULL)
                                destroy_dev(cpuctl_devs[cpu]);
                }
                free(cpuctl_devs, M_CPUCTL);
                break;
        case MOD_SHUTDOWN:
                break;
        default:
                return (EOPNOTSUPP);
        }
        return (0);
}

DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
MODULE_VERSION(cpuctl, CPUCTL_VERSION);