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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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522e664644
In reboot and crash path, when we shut down the local APIC, the I/O APIC is still active. This may cause issues because external interrupts can still come in and disturb the local APIC during shutdown process. To quiet external interrupts, disable I/O APIC before shutdown local APIC. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com Cc: <stable@kernel.org> [ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
141 lines
3.2 KiB
C
141 lines
3.2 KiB
C
/*
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* Architecture specific (i386/x86_64) functions for kexec based crash dumps.
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*
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* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
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*
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* Copyright (C) IBM Corporation, 2004. All rights reserved.
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*
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/smp.h>
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#include <linux/reboot.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/elf.h>
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#include <linux/elfcore.h>
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#include <linux/module.h>
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#include <asm/processor.h>
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#include <asm/hardirq.h>
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#include <asm/nmi.h>
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#include <asm/hw_irq.h>
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#include <asm/apic.h>
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#include <asm/hpet.h>
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#include <linux/kdebug.h>
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#include <asm/cpu.h>
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#include <asm/reboot.h>
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#include <asm/virtext.h>
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int in_crash_kexec;
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/*
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* This is used to VMCLEAR all VMCSs loaded on the
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* processor. And when loading kvm_intel module, the
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* callback function pointer will be assigned.
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*
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* protected by rcu.
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*/
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crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss = NULL;
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EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss);
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static inline void cpu_crash_vmclear_loaded_vmcss(void)
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{
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crash_vmclear_fn *do_vmclear_operation = NULL;
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rcu_read_lock();
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do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss);
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if (do_vmclear_operation)
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do_vmclear_operation();
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rcu_read_unlock();
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}
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#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
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static void kdump_nmi_callback(int cpu, struct pt_regs *regs)
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{
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#ifdef CONFIG_X86_32
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struct pt_regs fixed_regs;
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#endif
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#ifdef CONFIG_X86_32
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if (!user_mode_vm(regs)) {
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crash_fixup_ss_esp(&fixed_regs, regs);
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regs = &fixed_regs;
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}
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#endif
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crash_save_cpu(regs, cpu);
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/*
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* VMCLEAR VMCSs loaded on all cpus if needed.
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*/
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cpu_crash_vmclear_loaded_vmcss();
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/* Disable VMX or SVM if needed.
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*
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* We need to disable virtualization on all CPUs.
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* Having VMX or SVM enabled on any CPU may break rebooting
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* after the kdump kernel has finished its task.
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*/
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cpu_emergency_vmxoff();
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cpu_emergency_svm_disable();
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disable_local_APIC();
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}
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static void kdump_nmi_shootdown_cpus(void)
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{
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in_crash_kexec = 1;
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nmi_shootdown_cpus(kdump_nmi_callback);
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disable_local_APIC();
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}
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#else
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static void kdump_nmi_shootdown_cpus(void)
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{
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/* There are no cpus to shootdown */
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}
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#endif
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void native_machine_crash_shutdown(struct pt_regs *regs)
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{
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/* This function is only called after the system
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* has panicked or is otherwise in a critical state.
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* The minimum amount of code to allow a kexec'd kernel
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* to run successfully needs to happen here.
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*
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* In practice this means shooting down the other cpus in
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* an SMP system.
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*/
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/* The kernel is broken so disable interrupts */
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local_irq_disable();
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kdump_nmi_shootdown_cpus();
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/*
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* VMCLEAR VMCSs loaded on this cpu if needed.
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*/
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cpu_crash_vmclear_loaded_vmcss();
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/* Booting kdump kernel with VMX or SVM enabled won't work,
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* because (among other limitations) we can't disable paging
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* with the virt flags.
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*/
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cpu_emergency_vmxoff();
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cpu_emergency_svm_disable();
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#ifdef CONFIG_X86_IO_APIC
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/* Prevent crash_kexec() from deadlocking on ioapic_lock. */
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ioapic_zap_locks();
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disable_IO_APIC();
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#endif
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lapic_shutdown();
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#ifdef CONFIG_HPET_TIMER
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hpet_disable();
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#endif
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crash_save_cpu(regs, safe_smp_processor_id());
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}
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