root/usr/src/uts/i86pc/os/mlsetup.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2012 Gary Mills
 *
 * Copyright (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2011 by Delphix. All rights reserved.
 * Copyright 2019 Joyent, Inc.
 * Copyright 2024 Oxide Computer Company
 */
/*
 * Copyright (c) 2010, Intel Corporation.
 * All rights reserved.
 */

#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/disp.h>
#include <sys/promif.h>
#include <sys/clock.h>
#include <sys/cpuvar.h>
#include <sys/stack.h>
#include <vm/as.h>
#include <vm/hat.h>
#include <sys/reboot.h>
#include <sys/avintr.h>
#include <sys/vtrace.h>
#include <sys/proc.h>
#include <sys/thread.h>
#include <sys/cpupart.h>
#include <sys/pset.h>
#include <sys/copyops.h>
#include <sys/pg.h>
#include <sys/disp.h>
#include <sys/debug.h>
#include <sys/sunddi.h>
#include <sys/x86_archext.h>
#include <sys/privregs.h>
#include <sys/machsystm.h>
#include <sys/ontrap.h>
#include <sys/bootconf.h>
#include <sys/boot_console.h>
#include <sys/kdi_machimpl.h>
#include <sys/archsystm.h>
#include <sys/promif.h>
#include <sys/pci_cfgspace.h>
#include <sys/apic.h>
#include <sys/apic_common.h>
#include <sys/bootvfs.h>
#include <sys/tsc.h>
#include <sys/smt.h>
#ifdef __xpv
#include <sys/hypervisor.h>
#else
#include <sys/xpv_support.h>
#endif

/*
 * some globals for patching the result of cpuid
 * to solve problems w/ creative cpu vendors
 */

extern uint32_t cpuid_feature_ecx_include;
extern uint32_t cpuid_feature_ecx_exclude;
extern uint32_t cpuid_feature_edx_include;
extern uint32_t cpuid_feature_edx_exclude;

nmi_action_t nmi_action = NMI_ACTION_UNSET;

/*
 * Set console mode
 */
static void
set_console_mode(uint8_t val)
{
        struct bop_regs rp = {0};

        rp.eax.byte.ah = 0x0;
        rp.eax.byte.al = val;
        rp.ebx.word.bx = 0x0;

        BOP_DOINT(bootops, 0x10, &rp);
}


/*
 * Setup routine called right before main(). Interposing this function
 * before main() allows us to call it in a machine-independent fashion.
 */
void
mlsetup(struct regs *rp)
{
        u_longlong_t prop_value;
        char prop_str[BP_MAX_STRLEN];
        extern struct classfuncs sys_classfuncs;
        extern disp_t cpu0_disp;
        extern char t0stack[];
        extern int post_fastreboot;
        extern uint64_t plat_dr_options;

        ASSERT_STACK_ALIGNED();

        /*
         * initialize cpu_self
         */
        cpu[0]->cpu_self = cpu[0];

#if defined(__xpv)
        /*
         * Point at the hypervisor's virtual cpu structure
         */
        cpu[0]->cpu_m.mcpu_vcpu_info = &HYPERVISOR_shared_info->vcpu_info[0];
#endif

        /*
         * check if we've got special bits to clear or set
         * when checking cpu features
         */

        if (bootprop_getval("cpuid_feature_ecx_include", &prop_value) != 0)
                cpuid_feature_ecx_include = 0;
        else
                cpuid_feature_ecx_include = (uint32_t)prop_value;

        if (bootprop_getval("cpuid_feature_ecx_exclude", &prop_value) != 0)
                cpuid_feature_ecx_exclude = 0;
        else
                cpuid_feature_ecx_exclude = (uint32_t)prop_value;

        if (bootprop_getval("cpuid_feature_edx_include", &prop_value) != 0)
                cpuid_feature_edx_include = 0;
        else
                cpuid_feature_edx_include = (uint32_t)prop_value;

        if (bootprop_getval("cpuid_feature_edx_exclude", &prop_value) != 0)
                cpuid_feature_edx_exclude = 0;
        else
                cpuid_feature_edx_exclude = (uint32_t)prop_value;

#if !defined(__xpv)
        if (bootprop_getstr("nmi", prop_str, sizeof (prop_str)) == 0) {
                if (strcmp(prop_str, "ignore") == 0) {
                        nmi_action = NMI_ACTION_IGNORE;
                } else if (strcmp(prop_str, "panic") == 0) {
                        nmi_action = NMI_ACTION_PANIC;
                } else if (strcmp(prop_str, "kmdb") == 0) {
                        nmi_action = NMI_ACTION_KMDB;
                } else {
                        prom_printf("unix: ignoring unknown nmi=%s\n",
                            prop_str);
                }
        }

        /*
         * Check to see if KPTI has been explicitly enabled or disabled.
         * We have to check this before init_desctbls().
         */
        if (bootprop_getval("kpti", &prop_value) == 0) {
                kpti_enable = (uint64_t)(prop_value == 1);
                prom_printf("unix: forcing kpti to %s due to boot argument\n",
                    (kpti_enable == 1) ? "ON" : "OFF");
        } else {
                kpti_enable = 1;
        }

        if (bootprop_getval("pcid", &prop_value) == 0 && prop_value == 0) {
                prom_printf("unix: forcing pcid to OFF due to boot argument\n");
                x86_use_pcid = 0;
        } else if (kpti_enable != 1) {
                x86_use_pcid = 0;
        }

        /*
         * While we don't need to check this until later, we might as well do it
         * here.
         */
        if (bootprop_getstr("smt_enabled", prop_str, sizeof (prop_str)) == 0) {
                if (strcasecmp(prop_str, "false") == 0 ||
                    strcmp(prop_str, "0") == 0)
                        smt_boot_disable = 1;
        }

#endif

        /*
         * Initialize idt0, gdt0, ldt0_default, ktss0 and dftss.
         */
        init_desctbls();

        /*
         * initialize t0
         */
        t0.t_stk = (caddr_t)rp - MINFRAME;
        t0.t_stkbase = t0stack;
        t0.t_pri = maxclsyspri - 3;
        t0.t_schedflag = TS_LOAD | TS_DONT_SWAP;
        t0.t_procp = &p0;
        t0.t_plockp = &p0lock.pl_lock;
        t0.t_lwp = &lwp0;
        t0.t_forw = &t0;
        t0.t_back = &t0;
        t0.t_next = &t0;
        t0.t_prev = &t0;
        t0.t_cpu = cpu[0];
        t0.t_disp_queue = &cpu0_disp;
        t0.t_bind_cpu = PBIND_NONE;
        t0.t_bind_pset = PS_NONE;
        t0.t_bindflag = (uchar_t)default_binding_mode;
        t0.t_cpupart = &cp_default;
        t0.t_clfuncs = &sys_classfuncs.thread;
        t0.t_copyops = NULL;
        THREAD_ONPROC(&t0, CPU);

        lwp0.lwp_thread = &t0;
        lwp0.lwp_regs = (void *)rp;
        lwp0.lwp_procp = &p0;
        t0.t_tid = p0.p_lwpcnt = p0.p_lwprcnt = p0.p_lwpid = 1;

        p0.p_exec = NULL;
        p0.p_stat = SRUN;
        p0.p_flag = SSYS;
        p0.p_tlist = &t0;
        p0.p_stksize = 2*PAGESIZE;
        p0.p_stkpageszc = 0;
        p0.p_as = &kas;
        p0.p_lockp = &p0lock;
        p0.p_brkpageszc = 0;
        p0.p_t1_lgrpid = LGRP_NONE;
        p0.p_tr_lgrpid = LGRP_NONE;
        psecflags_default(&p0.p_secflags);

        sigorset(&p0.p_ignore, &ignoredefault);

        CPU->cpu_thread = &t0;
        bzero(&cpu0_disp, sizeof (disp_t));
        CPU->cpu_disp = &cpu0_disp;
        CPU->cpu_disp->disp_cpu = CPU;
        CPU->cpu_dispthread = &t0;
        CPU->cpu_idle_thread = &t0;
        CPU->cpu_flags = CPU_READY | CPU_RUNNING | CPU_EXISTS | CPU_ENABLE;
        CPU->cpu_dispatch_pri = t0.t_pri;

        CPU->cpu_id = 0;

        CPU->cpu_pri = 12;              /* initial PIL for the boot CPU */

        /*
         * Ensure that we have set the necessary feature bits before setting up
         * PCI config space access.
         */
        cpuid_execpass(cpu[0], CPUID_PASS_PRELUDE, x86_featureset);

        /*
         * lgrp_init() and possibly cpuid_pass1() need PCI config
         * space access
         */
#if defined(__xpv)
        if (DOMAIN_IS_INITDOMAIN(xen_info))
                pci_cfgspace_init();
#else
        pci_cfgspace_init();
        /*
         * Initialize the platform type from CPU 0 to ensure that
         * determine_platform() is only ever called once.
         */
        determine_platform();
#endif

        /*
         * While the BIOS may have already applied some microcode updates, we
         * may have more recent updates available that we'd like to apply.  The
         * application of said microcode may end up resulting in architecturally
         * visible changes (e.g., changed MSR or CPUID bits) which we'd like to
         * have in place before we start querying the CPU for its capabilities.
         * So we first run the IDENT pass to determine the specific CPU vendor,
         * model, rev etc., fill out cpu_ucode_info and update the microcode, if
         * necessary.
         */
        cpuid_execpass(cpu[0], CPUID_PASS_IDENT, NULL);
        ucode_init();
        ucode_check_boot();

        /*
         * Now we're ready to run the BASIC cpuid pass.
         *
         * The x86_featureset is initialized here based on the capabilities of
         * the boot CPU.  Note that if we choose to support CPUs that have
         * different feature sets (at which point we would almost certainly want
         * to set the feature bits to correspond to the feature minimum) this
         * value may be altered.
         */
        cpuid_execpass(cpu[0], CPUID_PASS_BASIC, x86_featureset);

#if !defined(__xpv)
        if ((get_hwenv() & HW_XEN_HVM) != 0)
                xen_hvm_init();

        /*
         * Before we do anything with the TSCs, we need to work around
         * Intel erratum BT81.  On some CPUs, warm reset does not
         * clear the TSC.  If we are on such a CPU, we will clear TSC ourselves
         * here.  Other CPUs will clear it when we boot them later, and the
         * resulting skew will be handled by tsc_sync_master()/_slave();
         * note that such skew already exists and has to be handled anyway.
         *
         * We do this only on metal.  This same problem can occur with a
         * hypervisor that does not happen to virtualise a TSC that starts from
         * zero, regardless of CPU type; however, we do not expect hypervisors
         * that do not virtualise TSC that way to handle writes to TSC
         * correctly, either.
         */
        if (get_hwenv() == HW_NATIVE &&
            cpuid_getvendor(CPU) == X86_VENDOR_Intel &&
            cpuid_getfamily(CPU) == 6 &&
            (cpuid_getmodel(CPU) == 0x2d || cpuid_getmodel(CPU) == 0x3e) &&
            is_x86_feature(x86_featureset, X86FSET_TSC)) {
                (void) wrmsr(REG_TSC, 0UL);
        }

        /*
         * Patch the tsc_read routine with appropriate set of instructions,
         * depending on the processor family and architecure, to read the
         * time-stamp counter while ensuring no out-of-order execution.
         * Patch it while the kernel text is still writable.
         *
         * The Xen hypervisor does not correctly report whether rdtscp is
         * supported or not, so we must assume that it is not.
         */
        if ((get_hwenv() & HW_XEN_HVM) == 0 &&
            is_x86_feature(x86_featureset, X86FSET_TSCP)) {
                patch_tsc_read(TSC_TSCP);
        } else if (is_x86_feature(x86_featureset, X86FSET_LFENCE_SER)) {
                ASSERT(is_x86_feature(x86_featureset, X86FSET_SSE2));
                patch_tsc_read(TSC_RDTSC_LFENCE);
        }

#endif  /* !__xpv */


#if !defined(__xpv)
        patch_memops(cpuid_getvendor(CPU));
#endif  /* !__xpv */

#if !defined(__xpv)
        /* XXPV what, if anything, should be dorked with here under xen? */

        /*
         * While we're thinking about the TSC, let's set up %cr4 so that
         * userland can issue rdtsc, and initialize the TSC_AUX value
         * (the cpuid) for the rdtscp instruction on appropriately
         * capable hardware.
         */
        if (is_x86_feature(x86_featureset, X86FSET_TSC))
                setcr4(getcr4() & ~CR4_TSD);

        if (is_x86_feature(x86_featureset, X86FSET_TSCP))
                (void) wrmsr(MSR_AMD_TSCAUX, 0);

        /*
         * Let's get the other %cr4 stuff while we're here. Note, we defer
         * enabling CR4_SMAP until startup_end(); however, that's importantly
         * before we start other CPUs. That ensures that it will be synced out
         * to other CPUs.
         */
        if (is_x86_feature(x86_featureset, X86FSET_DE))
                setcr4(getcr4() | CR4_DE);

        if (is_x86_feature(x86_featureset, X86FSET_SMEP))
                setcr4(getcr4() | CR4_SMEP);
#endif /* __xpv */


        /*
         * Initialize thread/cpu microstate accounting
         */
        init_mstate(&t0, LMS_SYSTEM);
        init_cpu_mstate(CPU, CMS_SYSTEM);

        /*
         * Initialize lists of available and active CPUs.
         */
        cpu_list_init(CPU);

        pg_cpu_bootstrap(CPU);

        /*
         * Now that we have taken over the GDT, IDT and have initialized
         * active CPU list it's time to inform kmdb if present.
         */
        if (boothowto & RB_DEBUG)
                kdi_idt_sync();

        if (BOP_GETPROPLEN(bootops, "efi-systab") < 0) {
                /*
                 * In BIOS system, explicitly set console to text mode (0x3)
                 * if this is a boot post Fast Reboot, and the console is set
                 * to CONS_SCREEN_TEXT.
                 */
                if (post_fastreboot &&
                    boot_console_type(NULL) == CONS_SCREEN_TEXT) {
                        set_console_mode(0x3);
                }
        }

        /*
         * If requested (boot -d) drop into kmdb.
         *
         * This must be done after cpu_list_init() on the 64-bit kernel
         * since taking a trap requires that we re-compute gsbase based
         * on the cpu list.
         */
        if (boothowto & RB_DEBUGENTER)
                kmdb_enter();

        cpu_vm_data_init(CPU);

        rp->r_fp = 0;   /* terminate kernel stack traces! */

        prom_init("kernel", (void *)NULL);

        /* User-set option overrides firmware value. */
        if (bootprop_getval(PLAT_DR_OPTIONS_NAME, &prop_value) == 0) {
                plat_dr_options = (uint64_t)prop_value;
        }
#if defined(__xpv)
        /* No support of DR operations on xpv */
        plat_dr_options = 0;
#else   /* __xpv */
        /* Flag PLAT_DR_FEATURE_ENABLED should only be set by DR driver. */
        plat_dr_options &= ~PLAT_DR_FEATURE_ENABLED;
#endif  /* __xpv */

        /*
         * Get value of "plat_dr_physmax" boot option.
         * It overrides values calculated from MSCT or SRAT table.
         */
        if (bootprop_getval(PLAT_DR_PHYSMAX_NAME, &prop_value) == 0) {
                plat_dr_physmax = ((uint64_t)prop_value) >> PAGESHIFT;
        }

        /* Get value of boot_ncpus. */
        if (bootprop_getval(BOOT_NCPUS_NAME, &prop_value) != 0) {
                boot_ncpus = NCPU;
        } else {
                boot_ncpus = (int)prop_value;
                if (boot_ncpus <= 0 || boot_ncpus > NCPU)
                        boot_ncpus = NCPU;
        }

        /*
         * Set max_ncpus and boot_max_ncpus to boot_ncpus if platform doesn't
         * support CPU DR operations.
         */
        if (plat_dr_support_cpu() == 0) {
                max_ncpus = boot_max_ncpus = boot_ncpus;
        } else {
                if (bootprop_getval(PLAT_MAX_NCPUS_NAME, &prop_value) != 0) {
                        max_ncpus = NCPU;
                } else {
                        max_ncpus = (int)prop_value;
                        if (max_ncpus <= 0 || max_ncpus > NCPU) {
                                max_ncpus = NCPU;
                        }
                        if (boot_ncpus > max_ncpus) {
                                boot_ncpus = max_ncpus;
                        }
                }

                if (bootprop_getval(BOOT_MAX_NCPUS_NAME, &prop_value) != 0) {
                        boot_max_ncpus = boot_ncpus;
                } else {
                        boot_max_ncpus = (int)prop_value;
                        if (boot_max_ncpus <= 0 || boot_max_ncpus > NCPU) {
                                boot_max_ncpus = boot_ncpus;
                        } else if (boot_max_ncpus > max_ncpus) {
                                boot_max_ncpus = max_ncpus;
                        }
                }
        }

        /*
         * Initialize the lgrp framework
         */
        lgrp_init(LGRP_INIT_STAGE1);

        if (boothowto & RB_HALT) {
                prom_printf("unix: kernel halted by -h flag\n");
                prom_enter_mon();
        }

        ASSERT_STACK_ALIGNED();

        if (workaround_errata(CPU) != 0)
                panic("critical workaround(s) missing for boot cpu");
}


void
mach_modpath(char *path, const char *filename)
{
        /*
         * Construct the directory path from the filename.
         */

        int len;
        char *p;
        const char isastr[] = "/amd64";
        size_t isalen = strlen(isastr);

        len = strlen(SYSTEM_BOOT_PATH "/kernel");
        (void) strcpy(path, SYSTEM_BOOT_PATH "/kernel ");
        path += len + 1;

        if ((p = strrchr(filename, '/')) == NULL)
                return;

        while (p > filename && *(p - 1) == '/')
                p--;    /* remove trailing '/' characters */
        if (p == filename)
                p++;    /* so "/" -is- the modpath in this case */

        /*
         * Remove optional isa-dependent directory name - the module
         * subsystem will put this back again (!)
         */
        len = p - filename;
        if (len > isalen &&
            strncmp(&filename[len - isalen], isastr, isalen) == 0)
                p -= isalen;

        /*
         * "/platform/mumblefrotz" + " " + MOD_DEFPATH
         */
        len += (p - filename) + 1 + strlen(MOD_DEFPATH) + 1;
        (void) strncpy(path, filename, p - filename);
}