linux_dsm_epyc7002/include/asm-x86_64/nmi.h
Ingo Molnar 6ebf622b25 [PATCH] disable NMI watchdog by default
there's a new NMI watchdog related problem: KVM crashes on certain
bzImages because ... we enable the NMI watchdog by default (even if the
user does not ask for it) , and no other OS on this planet does that so
KVM doesnt have emulation for that yet. So KVM injects a #GP, which
crashes the Linux guest:

 general protection fault: 0000 [#1]
 PREEMPT SMP
 Modules linked in:
 CPU:    0
 EIP:    0060:[<c011a8ae>]    Not tainted VLI
 EFLAGS: 00000246   (2.6.20-rc5-rt0 #3)
 EIP is at setup_apic_nmi_watchdog+0x26d/0x3d3

and no, i did /not/ request an nmi_watchdog on the boot command line!

Solution: turn off that darn thing! It's a debug tool, not a 'make life
harder' tool!!

with this patch the KVM guest boots up just fine.

And with this my laptop (Lenovo T60) also stopped its sporadic hard
hanging (sometimes in acpi_init(), sometimes later during bootup,
sometimes much later during actual use) as well. It hung with both
nmi_watchdog=1 and nmi_watchdog=2, so it's generally the fact of NMI
injection that is causing problems, not the NMI watchdog variant, nor
any particular bootup code.

[ NMI breaks on some systems, esp in combination with SMM -Arjan ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05 08:23:51 -08:00

84 lines
2.1 KiB
C

/*
* linux/include/asm-i386/nmi.h
*/
#ifndef ASM_NMI_H
#define ASM_NMI_H
#include <linux/pm.h>
#include <asm/io.h>
/**
* do_nmi_callback
*
* Check to see if a callback exists and execute it. Return 1
* if the handler exists and was handled successfully.
*/
int do_nmi_callback(struct pt_regs *regs, int cpu);
#ifdef CONFIG_PM
/** Replace the PM callback routine for NMI. */
struct pm_dev * set_nmi_pm_callback(pm_callback callback);
/** Unset the PM callback routine back to the default. */
void unset_nmi_pm_callback(struct pm_dev * dev);
#else
static inline struct pm_dev * set_nmi_pm_callback(pm_callback callback)
{
return 0;
}
static inline void unset_nmi_pm_callback(struct pm_dev * dev)
{
}
#endif /* CONFIG_PM */
extern void default_do_nmi(struct pt_regs *);
extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);
#define get_nmi_reason() inb(0x61)
extern int panic_on_timeout;
extern int unknown_nmi_panic;
extern int nmi_watchdog_enabled;
extern int check_nmi_watchdog(void);
extern int avail_to_resrv_perfctr_nmi_bit(unsigned int);
extern int avail_to_resrv_perfctr_nmi(unsigned int);
extern int reserve_perfctr_nmi(unsigned int);
extern void release_perfctr_nmi(unsigned int);
extern int reserve_evntsel_nmi(unsigned int);
extern void release_evntsel_nmi(unsigned int);
extern void setup_apic_nmi_watchdog (void *);
extern void stop_apic_nmi_watchdog (void *);
extern void disable_timer_nmi_watchdog(void);
extern void enable_timer_nmi_watchdog(void);
extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason);
extern void nmi_watchdog_default(void);
extern int setup_nmi_watchdog(char *);
extern atomic_t nmi_active;
extern unsigned int nmi_watchdog;
#define NMI_DEFAULT 0
#define NMI_NONE 0
#define NMI_IO_APIC 1
#define NMI_LOCAL_APIC 2
#define NMI_INVALID 3
struct ctl_table;
struct file;
extern int proc_nmi_enabled(struct ctl_table *, int , struct file *,
void __user *, size_t *, loff_t *);
extern int unknown_nmi_panic;
void __trigger_all_cpu_backtrace(void);
#define trigger_all_cpu_backtrace() __trigger_all_cpu_backtrace()
#endif /* ASM_NMI_H */