f-stack/freebsd/x86/x86/cpu_machdep.c

1472 lines
38 KiB
C

/*-
* Copyright (c) 2003 Peter Wemm.
* Copyright (c) 1992 Terrence R. Lambert.
* Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: @(#)machdep.c 7.4 (Berkeley) 6/3/91
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_acpi.h"
#include "opt_atpic.h"
#include "opt_cpu.h"
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_isa.h"
#include "opt_kdb.h"
#include "opt_kstack_pages.h"
#include "opt_maxmem.h"
#include "opt_mp_watchdog.h"
#include "opt_platform.h"
#ifdef __i386__
#include "opt_apic.h"
#endif
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/domainset.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/pcpu.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/cputypes.h>
#include <machine/specialreg.h>
#include <machine/md_var.h>
#include <machine/mp_watchdog.h>
#include <machine/tss.h>
#ifdef SMP
#include <machine/smp.h>
#endif
#ifdef CPU_ELAN
#include <machine/elan_mmcr.h>
#endif
#include <x86/acpica_machdep.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vm_param.h>
#include <isa/isareg.h>
#include <contrib/dev/acpica/include/acpi.h>
#define STATE_RUNNING 0x0
#define STATE_MWAIT 0x1
#define STATE_SLEEPING 0x2
#ifdef SMP
static u_int cpu_reset_proxyid;
static volatile u_int cpu_reset_proxy_active;
#endif
struct msr_op_arg {
u_int msr;
int op;
uint64_t arg1;
};
static void
x86_msr_op_one(void *argp)
{
struct msr_op_arg *a;
uint64_t v;
a = argp;
switch (a->op) {
case MSR_OP_ANDNOT:
v = rdmsr(a->msr);
v &= ~a->arg1;
wrmsr(a->msr, v);
break;
case MSR_OP_OR:
v = rdmsr(a->msr);
v |= a->arg1;
wrmsr(a->msr, v);
break;
case MSR_OP_WRITE:
wrmsr(a->msr, a->arg1);
break;
}
}
#define MSR_OP_EXMODE_MASK 0xf0000000
#define MSR_OP_OP_MASK 0x000000ff
void
x86_msr_op(u_int msr, u_int op, uint64_t arg1)
{
struct thread *td;
struct msr_op_arg a;
u_int exmode;
int bound_cpu, i, is_bound;
a.op = op & MSR_OP_OP_MASK;
MPASS(a.op == MSR_OP_ANDNOT || a.op == MSR_OP_OR ||
a.op == MSR_OP_WRITE);
exmode = op & MSR_OP_EXMODE_MASK;
MPASS(exmode == MSR_OP_LOCAL || exmode == MSR_OP_SCHED ||
exmode == MSR_OP_RENDEZVOUS);
a.msr = msr;
a.arg1 = arg1;
switch (exmode) {
case MSR_OP_LOCAL:
x86_msr_op_one(&a);
break;
case MSR_OP_SCHED:
td = curthread;
thread_lock(td);
is_bound = sched_is_bound(td);
bound_cpu = td->td_oncpu;
CPU_FOREACH(i) {
sched_bind(td, i);
x86_msr_op_one(&a);
}
if (is_bound)
sched_bind(td, bound_cpu);
else
sched_unbind(td);
thread_unlock(td);
break;
case MSR_OP_RENDEZVOUS:
smp_rendezvous(NULL, x86_msr_op_one, NULL, &a);
break;
}
}
/*
* Automatically initialized per CPU errata in cpu_idle_tun below.
*/
bool mwait_cpustop_broken = false;
SYSCTL_BOOL(_machdep, OID_AUTO, mwait_cpustop_broken, CTLFLAG_RDTUN,
&mwait_cpustop_broken, 0,
"Can not reliably wake MONITOR/MWAIT cpus without interrupts");
/*
* Flush the D-cache for non-DMA I/O so that the I-cache can
* be made coherent later.
*/
void
cpu_flush_dcache(void *ptr, size_t len)
{
/* Not applicable */
}
void
acpi_cpu_c1(void)
{
__asm __volatile("sti; hlt");
}
/*
* Use mwait to pause execution while waiting for an interrupt or
* another thread to signal that there is more work.
*
* NOTE: Interrupts will cause a wakeup; however, this function does
* not enable interrupt handling. The caller is responsible to enable
* interrupts.
*/
void
acpi_cpu_idle_mwait(uint32_t mwait_hint)
{
int *state;
uint64_t v;
/*
* A comment in Linux patch claims that 'CPUs run faster with
* speculation protection disabled. All CPU threads in a core
* must disable speculation protection for it to be
* disabled. Disable it while we are idle so the other
* hyperthread can run fast.'
*
* XXXKIB. Software coordination mode should be supported,
* but all Intel CPUs provide hardware coordination.
*/
state = &PCPU_PTR(monitorbuf)->idle_state;
KASSERT(atomic_load_int(state) == STATE_SLEEPING,
("cpu_mwait_cx: wrong monitorbuf state"));
atomic_store_int(state, STATE_MWAIT);
if (PCPU_GET(ibpb_set) || hw_ssb_active) {
v = rdmsr(MSR_IA32_SPEC_CTRL);
wrmsr(MSR_IA32_SPEC_CTRL, v & ~(IA32_SPEC_CTRL_IBRS |
IA32_SPEC_CTRL_STIBP | IA32_SPEC_CTRL_SSBD));
} else {
v = 0;
}
cpu_monitor(state, 0, 0);
if (atomic_load_int(state) == STATE_MWAIT)
cpu_mwait(MWAIT_INTRBREAK, mwait_hint);
/*
* SSB cannot be disabled while we sleep, or rather, if it was
* disabled, the sysctl thread will bind to our cpu to tweak
* MSR.
*/
if (v != 0)
wrmsr(MSR_IA32_SPEC_CTRL, v);
/*
* We should exit on any event that interrupts mwait, because
* that event might be a wanted interrupt.
*/
atomic_store_int(state, STATE_RUNNING);
}
/* Get current clock frequency for the given cpu id. */
int
cpu_est_clockrate(int cpu_id, uint64_t *rate)
{
uint64_t tsc1, tsc2;
uint64_t acnt, mcnt, perf;
register_t reg;
if (pcpu_find(cpu_id) == NULL || rate == NULL)
return (EINVAL);
#ifdef __i386__
if ((cpu_feature & CPUID_TSC) == 0)
return (EOPNOTSUPP);
#endif
/*
* If TSC is P-state invariant and APERF/MPERF MSRs do not exist,
* DELAY(9) based logic fails.
*/
if (tsc_is_invariant && !tsc_perf_stat)
return (EOPNOTSUPP);
#ifdef SMP
if (smp_cpus > 1) {
/* Schedule ourselves on the indicated cpu. */
thread_lock(curthread);
sched_bind(curthread, cpu_id);
thread_unlock(curthread);
}
#endif
/* Calibrate by measuring a short delay. */
reg = intr_disable();
if (tsc_is_invariant) {
wrmsr(MSR_MPERF, 0);
wrmsr(MSR_APERF, 0);
tsc1 = rdtsc();
DELAY(1000);
mcnt = rdmsr(MSR_MPERF);
acnt = rdmsr(MSR_APERF);
tsc2 = rdtsc();
intr_restore(reg);
perf = 1000 * acnt / mcnt;
*rate = (tsc2 - tsc1) * perf;
} else {
tsc1 = rdtsc();
DELAY(1000);
tsc2 = rdtsc();
intr_restore(reg);
*rate = (tsc2 - tsc1) * 1000;
}
#ifdef SMP
if (smp_cpus > 1) {
thread_lock(curthread);
sched_unbind(curthread);
thread_unlock(curthread);
}
#endif
return (0);
}
/*
* Shutdown the CPU as much as possible
*/
void
cpu_halt(void)
{
for (;;)
halt();
}
static void
cpu_reset_real(void)
{
struct region_descriptor null_idt;
int b;
disable_intr();
#ifdef CPU_ELAN
if (elan_mmcr != NULL)
elan_mmcr->RESCFG = 1;
#endif
#ifdef __i386__
if (cpu == CPU_GEODE1100) {
/* Attempt Geode's own reset */
outl(0xcf8, 0x80009044ul);
outl(0xcfc, 0xf);
}
#endif
#if !defined(BROKEN_KEYBOARD_RESET)
/*
* Attempt to do a CPU reset via the keyboard controller,
* do not turn off GateA20, as any machine that fails
* to do the reset here would then end up in no man's land.
*/
outb(IO_KBD + 4, 0xFE);
DELAY(500000); /* wait 0.5 sec to see if that did it */
#endif
/*
* Attempt to force a reset via the Reset Control register at
* I/O port 0xcf9. Bit 2 forces a system reset when it
* transitions from 0 to 1. Bit 1 selects the type of reset
* to attempt: 0 selects a "soft" reset, and 1 selects a
* "hard" reset. We try a "hard" reset. The first write sets
* bit 1 to select a "hard" reset and clears bit 2. The
* second write forces a 0 -> 1 transition in bit 2 to trigger
* a reset.
*/
outb(0xcf9, 0x2);
outb(0xcf9, 0x6);
DELAY(500000); /* wait 0.5 sec to see if that did it */
/*
* Attempt to force a reset via the Fast A20 and Init register
* at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
* Bit 0 asserts INIT# when set to 1. We are careful to only
* preserve bit 1 while setting bit 0. We also must clear bit
* 0 before setting it if it isn't already clear.
*/
b = inb(0x92);
if (b != 0xff) {
if ((b & 0x1) != 0)
outb(0x92, b & 0xfe);
outb(0x92, b | 0x1);
DELAY(500000); /* wait 0.5 sec to see if that did it */
}
printf("No known reset method worked, attempting CPU shutdown\n");
DELAY(1000000); /* wait 1 sec for printf to complete */
/* Wipe the IDT. */
null_idt.rd_limit = 0;
null_idt.rd_base = 0;
lidt(&null_idt);
/* "good night, sweet prince .... <THUNK!>" */
breakpoint();
/* NOTREACHED */
while(1);
}
#ifdef SMP
static void
cpu_reset_proxy(void)
{
cpu_reset_proxy_active = 1;
while (cpu_reset_proxy_active == 1)
ia32_pause(); /* Wait for other cpu to see that we've started */
printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
DELAY(1000000);
cpu_reset_real();
}
#endif
void
cpu_reset(void)
{
#ifdef SMP
struct monitorbuf *mb;
cpuset_t map;
u_int cnt;
if (smp_started) {
map = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &map);
CPU_ANDNOT(&map, &stopped_cpus);
if (!CPU_EMPTY(&map)) {
printf("cpu_reset: Stopping other CPUs\n");
stop_cpus(map);
}
if (PCPU_GET(cpuid) != 0) {
cpu_reset_proxyid = PCPU_GET(cpuid);
cpustop_restartfunc = cpu_reset_proxy;
cpu_reset_proxy_active = 0;
printf("cpu_reset: Restarting BSP\n");
/* Restart CPU #0. */
CPU_SETOF(0, &started_cpus);
mb = &pcpu_find(0)->pc_monitorbuf;
atomic_store_int(&mb->stop_state,
MONITOR_STOPSTATE_RUNNING);
cnt = 0;
while (cpu_reset_proxy_active == 0 && cnt < 10000000) {
ia32_pause();
cnt++; /* Wait for BSP to announce restart */
}
if (cpu_reset_proxy_active == 0) {
printf("cpu_reset: Failed to restart BSP\n");
} else {
cpu_reset_proxy_active = 2;
while (1)
ia32_pause();
/* NOTREACHED */
}
}
DELAY(1000000);
}
#endif
cpu_reset_real();
/* NOTREACHED */
}
bool
cpu_mwait_usable(void)
{
return ((cpu_feature2 & CPUID2_MON) != 0 && ((cpu_mon_mwait_flags &
(CPUID5_MON_MWAIT_EXT | CPUID5_MWAIT_INTRBREAK)) ==
(CPUID5_MON_MWAIT_EXT | CPUID5_MWAIT_INTRBREAK)));
}
void (*cpu_idle_hook)(sbintime_t) = NULL; /* ACPI idle hook. */
int cpu_amdc1e_bug = 0; /* AMD C1E APIC workaround required. */
static int idle_mwait = 1; /* Use MONITOR/MWAIT for short idle. */
SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RWTUN, &idle_mwait,
0, "Use MONITOR/MWAIT for short idle");
static void
cpu_idle_acpi(sbintime_t sbt)
{
int *state;
state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_SLEEPING);
/* See comments in cpu_idle_hlt(). */
disable_intr();
if (sched_runnable())
enable_intr();
else if (cpu_idle_hook)
cpu_idle_hook(sbt);
else
acpi_cpu_c1();
atomic_store_int(state, STATE_RUNNING);
}
static void
cpu_idle_hlt(sbintime_t sbt)
{
int *state;
state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_SLEEPING);
/*
* Since we may be in a critical section from cpu_idle(), if
* an interrupt fires during that critical section we may have
* a pending preemption. If the CPU halts, then that thread
* may not execute until a later interrupt awakens the CPU.
* To handle this race, check for a runnable thread after
* disabling interrupts and immediately return if one is
* found. Also, we must absolutely guarentee that hlt is
* the next instruction after sti. This ensures that any
* interrupt that fires after the call to disable_intr() will
* immediately awaken the CPU from hlt. Finally, please note
* that on x86 this works fine because of interrupts enabled only
* after the instruction following sti takes place, while IF is set
* to 1 immediately, allowing hlt instruction to acknowledge the
* interrupt.
*/
disable_intr();
if (sched_runnable())
enable_intr();
else
acpi_cpu_c1();
atomic_store_int(state, STATE_RUNNING);
}
static void
cpu_idle_mwait(sbintime_t sbt)
{
int *state;
state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_MWAIT);
/* See comments in cpu_idle_hlt(). */
disable_intr();
if (sched_runnable()) {
atomic_store_int(state, STATE_RUNNING);
enable_intr();
return;
}
cpu_monitor(state, 0, 0);
if (atomic_load_int(state) == STATE_MWAIT)
__asm __volatile("sti; mwait" : : "a" (MWAIT_C1), "c" (0));
else
enable_intr();
atomic_store_int(state, STATE_RUNNING);
}
static void
cpu_idle_spin(sbintime_t sbt)
{
int *state;
int i;
state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_RUNNING);
/*
* The sched_runnable() call is racy but as long as there is
* a loop missing it one time will have just a little impact if any
* (and it is much better than missing the check at all).
*/
for (i = 0; i < 1000; i++) {
if (sched_runnable())
return;
cpu_spinwait();
}
}
void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
void
cpu_idle(int busy)
{
uint64_t msr;
sbintime_t sbt = -1;
CTR2(KTR_SPARE2, "cpu_idle(%d) at %d",
busy, curcpu);
#ifdef MP_WATCHDOG
ap_watchdog(PCPU_GET(cpuid));
#endif
/* If we are busy - try to use fast methods. */
if (busy) {
if ((cpu_feature2 & CPUID2_MON) && idle_mwait) {
cpu_idle_mwait(busy);
goto out;
}
}
/* If we have time - switch timers into idle mode. */
if (!busy) {
critical_enter();
sbt = cpu_idleclock();
}
/* Apply AMD APIC timer C1E workaround. */
if (cpu_amdc1e_bug && cpu_disable_c3_sleep) {
msr = rdmsr(MSR_AMDK8_IPM);
if ((msr & (AMDK8_SMIONCMPHALT | AMDK8_C1EONCMPHALT)) != 0)
wrmsr(MSR_AMDK8_IPM, msr & ~(AMDK8_SMIONCMPHALT |
AMDK8_C1EONCMPHALT));
}
/* Call main idle method. */
cpu_idle_fn(sbt);
/* Switch timers back into active mode. */
if (!busy) {
cpu_activeclock();
critical_exit();
}
out:
CTR2(KTR_SPARE2, "cpu_idle(%d) at %d done",
busy, curcpu);
}
static int cpu_idle_apl31_workaround;
SYSCTL_INT(_machdep, OID_AUTO, idle_apl31, CTLFLAG_RW,
&cpu_idle_apl31_workaround, 0,
"Apollo Lake APL31 MWAIT bug workaround");
int
cpu_idle_wakeup(int cpu)
{
struct monitorbuf *mb;
int *state;
mb = &pcpu_find(cpu)->pc_monitorbuf;
state = &mb->idle_state;
switch (atomic_load_int(state)) {
case STATE_SLEEPING:
return (0);
case STATE_MWAIT:
atomic_store_int(state, STATE_RUNNING);
return (cpu_idle_apl31_workaround ? 0 : 1);
case STATE_RUNNING:
return (1);
default:
panic("bad monitor state");
return (1);
}
}
/*
* Ordered by speed/power consumption.
*/
static struct {
void *id_fn;
char *id_name;
int id_cpuid2_flag;
} idle_tbl[] = {
{ .id_fn = cpu_idle_spin, .id_name = "spin" },
{ .id_fn = cpu_idle_mwait, .id_name = "mwait",
.id_cpuid2_flag = CPUID2_MON },
{ .id_fn = cpu_idle_hlt, .id_name = "hlt" },
{ .id_fn = cpu_idle_acpi, .id_name = "acpi" },
};
static int
idle_sysctl_available(SYSCTL_HANDLER_ARGS)
{
char *avail, *p;
int error;
int i;
avail = malloc(256, M_TEMP, M_WAITOK);
p = avail;
for (i = 0; i < nitems(idle_tbl); i++) {
if (idle_tbl[i].id_cpuid2_flag != 0 &&
(cpu_feature2 & idle_tbl[i].id_cpuid2_flag) == 0)
continue;
if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
cpu_idle_hook == NULL)
continue;
p += sprintf(p, "%s%s", p != avail ? ", " : "",
idle_tbl[i].id_name);
}
error = sysctl_handle_string(oidp, avail, 0, req);
free(avail, M_TEMP);
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, idle_available,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
0, 0, idle_sysctl_available, "A",
"list of available idle functions");
static bool
cpu_idle_selector(const char *new_idle_name)
{
int i;
for (i = 0; i < nitems(idle_tbl); i++) {
if (idle_tbl[i].id_cpuid2_flag != 0 &&
(cpu_feature2 & idle_tbl[i].id_cpuid2_flag) == 0)
continue;
if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
cpu_idle_hook == NULL)
continue;
if (strcmp(idle_tbl[i].id_name, new_idle_name))
continue;
cpu_idle_fn = idle_tbl[i].id_fn;
if (bootverbose)
printf("CPU idle set to %s\n", idle_tbl[i].id_name);
return (true);
}
return (false);
}
static int
cpu_idle_sysctl(SYSCTL_HANDLER_ARGS)
{
char buf[16], *p;
int error, i;
p = "unknown";
for (i = 0; i < nitems(idle_tbl); i++) {
if (idle_tbl[i].id_fn == cpu_idle_fn) {
p = idle_tbl[i].id_name;
break;
}
}
strncpy(buf, p, sizeof(buf));
error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
if (error != 0 || req->newptr == NULL)
return (error);
return (cpu_idle_selector(buf) ? 0 : EINVAL);
}
SYSCTL_PROC(_machdep, OID_AUTO, idle,
CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 0, cpu_idle_sysctl, "A",
"currently selected idle function");
static void
cpu_idle_tun(void *unused __unused)
{
char tunvar[16];
if (TUNABLE_STR_FETCH("machdep.idle", tunvar, sizeof(tunvar)))
cpu_idle_selector(tunvar);
else if (cpu_vendor_id == CPU_VENDOR_AMD &&
CPUID_TO_FAMILY(cpu_id) == 0x17 && CPUID_TO_MODEL(cpu_id) == 0x1) {
/* Ryzen erratas 1057, 1109. */
cpu_idle_selector("hlt");
idle_mwait = 0;
mwait_cpustop_broken = true;
}
if (cpu_vendor_id == CPU_VENDOR_INTEL && cpu_id == 0x506c9) {
/*
* Apollo Lake errata APL31 (public errata APL30).
* Stores to the armed address range may not trigger
* MWAIT to resume execution. OS needs to use
* interrupts to wake processors from MWAIT-induced
* sleep states.
*/
cpu_idle_apl31_workaround = 1;
mwait_cpustop_broken = true;
}
TUNABLE_INT_FETCH("machdep.idle_apl31", &cpu_idle_apl31_workaround);
}
SYSINIT(cpu_idle_tun, SI_SUB_CPU, SI_ORDER_MIDDLE, cpu_idle_tun, NULL);
static int panic_on_nmi = 0xff;
SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RWTUN,
&panic_on_nmi, 0,
"Panic on NMI: 1 = H/W failure; 2 = unknown; 0xff = all");
int nmi_is_broadcast = 1;
SYSCTL_INT(_machdep, OID_AUTO, nmi_is_broadcast, CTLFLAG_RWTUN,
&nmi_is_broadcast, 0,
"Chipset NMI is broadcast");
int (*apei_nmi)(void);
void
nmi_call_kdb(u_int cpu, u_int type, struct trapframe *frame)
{
bool claimed = false;
#ifdef DEV_ISA
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(frame->tf_err)) {
claimed = true;
if ((panic_on_nmi & 1) != 0)
panic("NMI indicates hardware failure");
}
#endif /* DEV_ISA */
/* ACPI Platform Error Interfaces callback. */
if (apei_nmi != NULL && (*apei_nmi)())
claimed = true;
/*
* NMIs can be useful for debugging. They can be hooked up to a
* pushbutton, usually on an ISA, PCI, or PCIe card. They can also be
* generated by an IPMI BMC, either manually or in response to a
* watchdog timeout. For example, see the "power diag" command in
* ports/sysutils/ipmitool. They can also be generated by a
* hypervisor; see "bhyvectl --inject-nmi".
*/
#ifdef KDB
if (!claimed && (panic_on_nmi & 2) != 0) {
if (debugger_on_panic) {
printf("NMI/cpu%d ... going to debugger\n", cpu);
claimed = kdb_trap(type, 0, frame);
}
}
#endif /* KDB */
if (!claimed && panic_on_nmi != 0)
panic("NMI");
}
void
nmi_handle_intr(u_int type, struct trapframe *frame)
{
#ifdef SMP
if (nmi_is_broadcast) {
nmi_call_kdb_smp(type, frame);
return;
}
#endif
nmi_call_kdb(PCPU_GET(cpuid), type, frame);
}
static int hw_ibrs_active;
int hw_ibrs_ibpb_active;
int hw_ibrs_disable = 1;
SYSCTL_INT(_hw, OID_AUTO, ibrs_active, CTLFLAG_RD, &hw_ibrs_active, 0,
"Indirect Branch Restricted Speculation active");
SYSCTL_NODE(_machdep_mitigations, OID_AUTO, ibrs,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Indirect Branch Restricted Speculation active");
SYSCTL_INT(_machdep_mitigations_ibrs, OID_AUTO, active, CTLFLAG_RD,
&hw_ibrs_active, 0, "Indirect Branch Restricted Speculation active");
void
hw_ibrs_recalculate(bool for_all_cpus)
{
if ((cpu_ia32_arch_caps & IA32_ARCH_CAP_IBRS_ALL) != 0) {
x86_msr_op(MSR_IA32_SPEC_CTRL, (for_all_cpus ?
MSR_OP_RENDEZVOUS : MSR_OP_LOCAL) |
(hw_ibrs_disable != 0 ? MSR_OP_ANDNOT : MSR_OP_OR),
IA32_SPEC_CTRL_IBRS);
hw_ibrs_active = hw_ibrs_disable == 0;
hw_ibrs_ibpb_active = 0;
} else {
hw_ibrs_active = hw_ibrs_ibpb_active = (cpu_stdext_feature3 &
CPUID_STDEXT3_IBPB) != 0 && !hw_ibrs_disable;
}
}
static int
hw_ibrs_disable_handler(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = hw_ibrs_disable;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
hw_ibrs_disable = val != 0;
hw_ibrs_recalculate(true);
return (0);
}
SYSCTL_PROC(_hw, OID_AUTO, ibrs_disable, CTLTYPE_INT | CTLFLAG_RWTUN |
CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0, hw_ibrs_disable_handler, "I",
"Disable Indirect Branch Restricted Speculation");
SYSCTL_PROC(_machdep_mitigations_ibrs, OID_AUTO, disable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
hw_ibrs_disable_handler, "I",
"Disable Indirect Branch Restricted Speculation");
int hw_ssb_active;
int hw_ssb_disable;
SYSCTL_INT(_hw, OID_AUTO, spec_store_bypass_disable_active, CTLFLAG_RD,
&hw_ssb_active, 0,
"Speculative Store Bypass Disable active");
SYSCTL_NODE(_machdep_mitigations, OID_AUTO, ssb,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Speculative Store Bypass Disable active");
SYSCTL_INT(_machdep_mitigations_ssb, OID_AUTO, active, CTLFLAG_RD,
&hw_ssb_active, 0, "Speculative Store Bypass Disable active");
static void
hw_ssb_set(bool enable, bool for_all_cpus)
{
if ((cpu_stdext_feature3 & CPUID_STDEXT3_SSBD) == 0) {
hw_ssb_active = 0;
return;
}
hw_ssb_active = enable;
x86_msr_op(MSR_IA32_SPEC_CTRL,
(enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
(for_all_cpus ? MSR_OP_SCHED : MSR_OP_LOCAL), IA32_SPEC_CTRL_SSBD);
}
void
hw_ssb_recalculate(bool all_cpus)
{
switch (hw_ssb_disable) {
default:
hw_ssb_disable = 0;
/* FALLTHROUGH */
case 0: /* off */
hw_ssb_set(false, all_cpus);
break;
case 1: /* on */
hw_ssb_set(true, all_cpus);
break;
case 2: /* auto */
hw_ssb_set((cpu_ia32_arch_caps & IA32_ARCH_CAP_SSB_NO) != 0 ?
false : true, all_cpus);
break;
}
}
static int
hw_ssb_disable_handler(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = hw_ssb_disable;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
hw_ssb_disable = val;
hw_ssb_recalculate(true);
return (0);
}
SYSCTL_PROC(_hw, OID_AUTO, spec_store_bypass_disable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
hw_ssb_disable_handler, "I",
"Speculative Store Bypass Disable (0 - off, 1 - on, 2 - auto");
SYSCTL_PROC(_machdep_mitigations_ssb, OID_AUTO, disable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
hw_ssb_disable_handler, "I",
"Speculative Store Bypass Disable (0 - off, 1 - on, 2 - auto");
int hw_mds_disable;
/*
* Handler for Microarchitectural Data Sampling issues. Really not a
* pointer to C function: on amd64 the code must not change any CPU
* architectural state except possibly %rflags. Also, it is always
* called with interrupts disabled.
*/
void mds_handler_void(void);
void mds_handler_verw(void);
void mds_handler_ivb(void);
void mds_handler_bdw(void);
void mds_handler_skl_sse(void);
void mds_handler_skl_avx(void);
void mds_handler_skl_avx512(void);
void mds_handler_silvermont(void);
void (*mds_handler)(void) = mds_handler_void;
static int
sysctl_hw_mds_disable_state_handler(SYSCTL_HANDLER_ARGS)
{
const char *state;
if (mds_handler == mds_handler_void)
state = "inactive";
else if (mds_handler == mds_handler_verw)
state = "VERW";
else if (mds_handler == mds_handler_ivb)
state = "software IvyBridge";
else if (mds_handler == mds_handler_bdw)
state = "software Broadwell";
else if (mds_handler == mds_handler_skl_sse)
state = "software Skylake SSE";
else if (mds_handler == mds_handler_skl_avx)
state = "software Skylake AVX";
else if (mds_handler == mds_handler_skl_avx512)
state = "software Skylake AVX512";
else if (mds_handler == mds_handler_silvermont)
state = "software Silvermont";
else
state = "unknown";
return (SYSCTL_OUT(req, state, strlen(state)));
}
SYSCTL_PROC(_hw, OID_AUTO, mds_disable_state,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_hw_mds_disable_state_handler, "A",
"Microarchitectural Data Sampling Mitigation state");
SYSCTL_NODE(_machdep_mitigations, OID_AUTO, mds,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Microarchitectural Data Sampling Mitigation state");
SYSCTL_PROC(_machdep_mitigations_mds, OID_AUTO, state,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_hw_mds_disable_state_handler, "A",
"Microarchitectural Data Sampling Mitigation state");
_Static_assert(__offsetof(struct pcpu, pc_mds_tmp) % 64 == 0, "MDS AVX512");
void
hw_mds_recalculate(void)
{
struct pcpu *pc;
vm_offset_t b64;
u_long xcr0;
int i;
/*
* Allow user to force VERW variant even if MD_CLEAR is not
* reported. For instance, hypervisor might unknowingly
* filter the cap out.
* For the similar reasons, and for testing, allow to enable
* mitigation even when MDS_NO cap is set.
*/
if (cpu_vendor_id != CPU_VENDOR_INTEL || hw_mds_disable == 0 ||
((cpu_ia32_arch_caps & IA32_ARCH_CAP_MDS_NO) != 0 &&
hw_mds_disable == 3)) {
mds_handler = mds_handler_void;
} else if (((cpu_stdext_feature3 & CPUID_STDEXT3_MD_CLEAR) != 0 &&
hw_mds_disable == 3) || hw_mds_disable == 1) {
mds_handler = mds_handler_verw;
} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
(CPUID_TO_MODEL(cpu_id) == 0x2e || CPUID_TO_MODEL(cpu_id) == 0x1e ||
CPUID_TO_MODEL(cpu_id) == 0x1f || CPUID_TO_MODEL(cpu_id) == 0x1a ||
CPUID_TO_MODEL(cpu_id) == 0x2f || CPUID_TO_MODEL(cpu_id) == 0x25 ||
CPUID_TO_MODEL(cpu_id) == 0x2c || CPUID_TO_MODEL(cpu_id) == 0x2d ||
CPUID_TO_MODEL(cpu_id) == 0x2a || CPUID_TO_MODEL(cpu_id) == 0x3e ||
CPUID_TO_MODEL(cpu_id) == 0x3a) &&
(hw_mds_disable == 2 || hw_mds_disable == 3)) {
/*
* Nehalem, SandyBridge, IvyBridge
*/
CPU_FOREACH(i) {
pc = pcpu_find(i);
if (pc->pc_mds_buf == NULL) {
pc->pc_mds_buf = malloc_domainset(672, M_TEMP,
DOMAINSET_PREF(pc->pc_domain), M_WAITOK);
bzero(pc->pc_mds_buf, 16);
}
}
mds_handler = mds_handler_ivb;
} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
(CPUID_TO_MODEL(cpu_id) == 0x3f || CPUID_TO_MODEL(cpu_id) == 0x3c ||
CPUID_TO_MODEL(cpu_id) == 0x45 || CPUID_TO_MODEL(cpu_id) == 0x46 ||
CPUID_TO_MODEL(cpu_id) == 0x56 || CPUID_TO_MODEL(cpu_id) == 0x4f ||
CPUID_TO_MODEL(cpu_id) == 0x47 || CPUID_TO_MODEL(cpu_id) == 0x3d) &&
(hw_mds_disable == 2 || hw_mds_disable == 3)) {
/*
* Haswell, Broadwell
*/
CPU_FOREACH(i) {
pc = pcpu_find(i);
if (pc->pc_mds_buf == NULL) {
pc->pc_mds_buf = malloc_domainset(1536, M_TEMP,
DOMAINSET_PREF(pc->pc_domain), M_WAITOK);
bzero(pc->pc_mds_buf, 16);
}
}
mds_handler = mds_handler_bdw;
} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
((CPUID_TO_MODEL(cpu_id) == 0x55 && (cpu_id &
CPUID_STEPPING) <= 5) ||
CPUID_TO_MODEL(cpu_id) == 0x4e || CPUID_TO_MODEL(cpu_id) == 0x5e ||
(CPUID_TO_MODEL(cpu_id) == 0x8e && (cpu_id &
CPUID_STEPPING) <= 0xb) ||
(CPUID_TO_MODEL(cpu_id) == 0x9e && (cpu_id &
CPUID_STEPPING) <= 0xc)) &&
(hw_mds_disable == 2 || hw_mds_disable == 3)) {
/*
* Skylake, KabyLake, CoffeeLake, WhiskeyLake,
* CascadeLake
*/
CPU_FOREACH(i) {
pc = pcpu_find(i);
if (pc->pc_mds_buf == NULL) {
pc->pc_mds_buf = malloc_domainset(6 * 1024,
M_TEMP, DOMAINSET_PREF(pc->pc_domain),
M_WAITOK);
b64 = (vm_offset_t)malloc_domainset(64 + 63,
M_TEMP, DOMAINSET_PREF(pc->pc_domain),
M_WAITOK);
pc->pc_mds_buf64 = (void *)roundup2(b64, 64);
bzero(pc->pc_mds_buf64, 64);
}
}
xcr0 = rxcr(0);
if ((xcr0 & XFEATURE_ENABLED_ZMM_HI256) != 0 &&
(cpu_stdext_feature & CPUID_STDEXT_AVX512DQ) != 0)
mds_handler = mds_handler_skl_avx512;
else if ((xcr0 & XFEATURE_ENABLED_AVX) != 0 &&
(cpu_feature2 & CPUID2_AVX) != 0)
mds_handler = mds_handler_skl_avx;
else
mds_handler = mds_handler_skl_sse;
} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
((CPUID_TO_MODEL(cpu_id) == 0x37 ||
CPUID_TO_MODEL(cpu_id) == 0x4a ||
CPUID_TO_MODEL(cpu_id) == 0x4c ||
CPUID_TO_MODEL(cpu_id) == 0x4d ||
CPUID_TO_MODEL(cpu_id) == 0x5a ||
CPUID_TO_MODEL(cpu_id) == 0x5d ||
CPUID_TO_MODEL(cpu_id) == 0x6e ||
CPUID_TO_MODEL(cpu_id) == 0x65 ||
CPUID_TO_MODEL(cpu_id) == 0x75 ||
CPUID_TO_MODEL(cpu_id) == 0x1c ||
CPUID_TO_MODEL(cpu_id) == 0x26 ||
CPUID_TO_MODEL(cpu_id) == 0x27 ||
CPUID_TO_MODEL(cpu_id) == 0x35 ||
CPUID_TO_MODEL(cpu_id) == 0x36 ||
CPUID_TO_MODEL(cpu_id) == 0x7a))) {
/* Silvermont, Airmont */
CPU_FOREACH(i) {
pc = pcpu_find(i);
if (pc->pc_mds_buf == NULL)
pc->pc_mds_buf = malloc(256, M_TEMP, M_WAITOK);
}
mds_handler = mds_handler_silvermont;
} else {
hw_mds_disable = 0;
mds_handler = mds_handler_void;
}
}
static void
hw_mds_recalculate_boot(void *arg __unused)
{
hw_mds_recalculate();
}
SYSINIT(mds_recalc, SI_SUB_SMP, SI_ORDER_ANY, hw_mds_recalculate_boot, NULL);
static int
sysctl_mds_disable_handler(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = hw_mds_disable;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (val < 0 || val > 3)
return (EINVAL);
hw_mds_disable = val;
hw_mds_recalculate();
return (0);
}
SYSCTL_PROC(_hw, OID_AUTO, mds_disable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
sysctl_mds_disable_handler, "I",
"Microarchitectural Data Sampling Mitigation "
"(0 - off, 1 - on VERW, 2 - on SW, 3 - on AUTO");
SYSCTL_PROC(_machdep_mitigations_mds, OID_AUTO, disable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
sysctl_mds_disable_handler, "I",
"Microarchitectural Data Sampling Mitigation "
"(0 - off, 1 - on VERW, 2 - on SW, 3 - on AUTO");
/*
* Intel Transactional Memory Asynchronous Abort Mitigation
* CVE-2019-11135
*/
int x86_taa_enable;
int x86_taa_state;
enum {
TAA_NONE = 0, /* No mitigation enabled */
TAA_TSX_DISABLE = 1, /* Disable TSX via MSR */
TAA_VERW = 2, /* Use VERW mitigation */
TAA_AUTO = 3, /* Automatically select the mitigation */
/* The states below are not selectable by the operator */
TAA_TAA_UC = 4, /* Mitigation present in microcode */
TAA_NOT_PRESENT = 5 /* TSX is not present */
};
static void
taa_set(bool enable, bool all)
{
x86_msr_op(MSR_IA32_TSX_CTRL,
(enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
(all ? MSR_OP_RENDEZVOUS : MSR_OP_LOCAL),
IA32_TSX_CTRL_RTM_DISABLE | IA32_TSX_CTRL_TSX_CPUID_CLEAR);
}
void
x86_taa_recalculate(void)
{
static int taa_saved_mds_disable = 0;
int taa_need = 0, taa_state = 0;
int mds_disable = 0, need_mds_recalc = 0;
/* Check CPUID.07h.EBX.HLE and RTM for the presence of TSX */
if ((cpu_stdext_feature & CPUID_STDEXT_HLE) == 0 ||
(cpu_stdext_feature & CPUID_STDEXT_RTM) == 0) {
/* TSX is not present */
x86_taa_state = TAA_NOT_PRESENT;
return;
}
/* Check to see what mitigation options the CPU gives us */
if (cpu_ia32_arch_caps & IA32_ARCH_CAP_TAA_NO) {
/* CPU is not suseptible to TAA */
taa_need = TAA_TAA_UC;
} else if (cpu_ia32_arch_caps & IA32_ARCH_CAP_TSX_CTRL) {
/*
* CPU can turn off TSX. This is the next best option
* if TAA_NO hardware mitigation isn't present
*/
taa_need = TAA_TSX_DISABLE;
} else {
/* No TSX/TAA specific remedies are available. */
if (x86_taa_enable == TAA_TSX_DISABLE) {
if (bootverbose)
printf("TSX control not available\n");
return;
} else
taa_need = TAA_VERW;
}
/* Can we automatically take action, or are we being forced? */
if (x86_taa_enable == TAA_AUTO)
taa_state = taa_need;
else
taa_state = x86_taa_enable;
/* No state change, nothing to do */
if (taa_state == x86_taa_state) {
if (bootverbose)
printf("No TSX change made\n");
return;
}
/* Does the MSR need to be turned on or off? */
if (taa_state == TAA_TSX_DISABLE)
taa_set(true, true);
else if (x86_taa_state == TAA_TSX_DISABLE)
taa_set(false, true);
/* Does MDS need to be set to turn on VERW? */
if (taa_state == TAA_VERW) {
taa_saved_mds_disable = hw_mds_disable;
mds_disable = hw_mds_disable = 1;
need_mds_recalc = 1;
} else if (x86_taa_state == TAA_VERW) {
mds_disable = hw_mds_disable = taa_saved_mds_disable;
need_mds_recalc = 1;
}
if (need_mds_recalc) {
hw_mds_recalculate();
if (mds_disable != hw_mds_disable) {
if (bootverbose)
printf("Cannot change MDS state for TAA\n");
/* Don't update our state */
return;
}
}
x86_taa_state = taa_state;
return;
}
static void
taa_recalculate_boot(void * arg __unused)
{
x86_taa_recalculate();
}
SYSINIT(taa_recalc, SI_SUB_SMP, SI_ORDER_ANY, taa_recalculate_boot, NULL);
SYSCTL_NODE(_machdep_mitigations, OID_AUTO, taa,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TSX Asynchronous Abort Mitigation");
static int
sysctl_taa_handler(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = x86_taa_enable;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (val < TAA_NONE || val > TAA_AUTO)
return (EINVAL);
x86_taa_enable = val;
x86_taa_recalculate();
return (0);
}
SYSCTL_PROC(_machdep_mitigations_taa, OID_AUTO, enable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
sysctl_taa_handler, "I",
"TAA Mitigation enablement control "
"(0 - off, 1 - disable TSX, 2 - VERW, 3 - on AUTO");
static int
sysctl_taa_state_handler(SYSCTL_HANDLER_ARGS)
{
const char *state;
switch (x86_taa_state) {
case TAA_NONE:
state = "inactive";
break;
case TAA_TSX_DISABLE:
state = "TSX disabled";
break;
case TAA_VERW:
state = "VERW";
break;
case TAA_TAA_UC:
state = "Mitigated in microcode";
break;
case TAA_NOT_PRESENT:
state = "TSX not present";
break;
default:
state = "unknown";
}
return (SYSCTL_OUT(req, state, strlen(state)));
}
SYSCTL_PROC(_machdep_mitigations_taa, OID_AUTO, state,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_taa_state_handler, "A",
"TAA Mitigation state");
int __read_frequently cpu_flush_rsb_ctxsw;
SYSCTL_INT(_machdep_mitigations, OID_AUTO, flush_rsb_ctxsw,
CTLFLAG_RW | CTLFLAG_NOFETCH, &cpu_flush_rsb_ctxsw, 0,
"Flush Return Stack Buffer on context switch");
SYSCTL_NODE(_machdep_mitigations, OID_AUTO, rngds,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"MCU Optimization, disable RDSEED mitigation");
int x86_rngds_mitg_enable = 1;
void
x86_rngds_mitg_recalculate(bool all_cpus)
{
if ((cpu_stdext_feature3 & CPUID_STDEXT3_MCUOPT) == 0)
return;
x86_msr_op(MSR_IA32_MCU_OPT_CTRL,
(x86_rngds_mitg_enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
(all_cpus ? MSR_OP_RENDEZVOUS : MSR_OP_LOCAL),
IA32_RNGDS_MITG_DIS);
}
static int
sysctl_rngds_mitg_enable_handler(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = x86_rngds_mitg_enable;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
x86_rngds_mitg_enable = val;
x86_rngds_mitg_recalculate(true);
return (0);
}
SYSCTL_PROC(_machdep_mitigations_rngds, OID_AUTO, enable, CTLTYPE_INT |
CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
sysctl_rngds_mitg_enable_handler, "I",
"MCU Optimization, disabling RDSEED mitigation control "
"(0 - mitigation disabled (RDSEED optimized), 1 - mitigation enabled");
static int
sysctl_rngds_state_handler(SYSCTL_HANDLER_ARGS)
{
const char *state;
if ((cpu_stdext_feature3 & CPUID_STDEXT3_MCUOPT) == 0) {
state = "Not applicable";
} else if (x86_rngds_mitg_enable == 0) {
state = "RDSEED not serialized";
} else {
state = "Mitigated";
}
return (SYSCTL_OUT(req, state, strlen(state)));
}
SYSCTL_PROC(_machdep_mitigations_rngds, OID_AUTO, state,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_rngds_state_handler, "A",
"MCU Optimization state");
/*
* Enable and restore kernel text write permissions.
* Callers must ensure that disable_wp()/restore_wp() are executed
* without rescheduling on the same core.
*/
bool
disable_wp(void)
{
u_int cr0;
cr0 = rcr0();
if ((cr0 & CR0_WP) == 0)
return (false);
load_cr0(cr0 & ~CR0_WP);
return (true);
}
void
restore_wp(bool old_wp)
{
if (old_wp)
load_cr0(rcr0() | CR0_WP);
}
bool
acpi_get_fadt_bootflags(uint16_t *flagsp)
{
#ifdef DEV_ACPI
ACPI_TABLE_FADT *fadt;
vm_paddr_t physaddr;
physaddr = acpi_find_table(ACPI_SIG_FADT);
if (physaddr == 0)
return (false);
fadt = acpi_map_table(physaddr, ACPI_SIG_FADT);
if (fadt == NULL)
return (false);
*flagsp = fadt->BootFlags;
acpi_unmap_table(fadt);
return (true);
#else
return (false);
#endif
}