crash_clear_loaded_vmcss is added to VMCLEAR vmcss loaded on all cpus. And when loading kvm_intel module, the function pointer will be made valid. The percpu variable vmclear_skipped is added to flag the case that if loaded_vmcss_on_cpu list is being modified while the machine crashes and doing kdump, the vmclear here can be skipped. Signed-off-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx> --- arch/x86/include/asm/kexec.h | 3 +++ arch/x86/kernel/crash.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 317ff17..d892211 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -163,6 +163,9 @@ struct kimage_arch { }; #endif +extern void (*crash_clear_loaded_vmcss)(void); +DECLARE_PER_CPU(int, vmclear_skipped); + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 13ad899..b9f264e 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -16,6 +16,7 @@ #include <linux/delay.h> #include <linux/elf.h> #include <linux/elfcore.h> +#include <linux/module.h> #include <asm/processor.h> #include <asm/hardirq.h> @@ -30,6 +31,27 @@ int in_crash_kexec; +/* + * This is used to VMCLEAR vmcss loaded on all + * cpus. And when loading kvm_intel module, the + * function pointer will be made valid. + */ +void (*crash_clear_loaded_vmcss)(void) = NULL; +EXPORT_SYMBOL_GPL(crash_clear_loaded_vmcss); + +DEFINE_PER_CPU(int, vmclear_skipped) = 1; +EXPORT_SYMBOL_GPL(vmclear_skipped); + +static void cpu_emergency_clear_loaded_vmcss(void) +{ + int cpu = raw_smp_processor_id(); + int skipped; + + skipped = per_cpu(vmclear_skipped, cpu); + if (!skipped && crash_clear_loaded_vmcss) + crash_clear_loaded_vmcss(); +} + #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) static void kdump_nmi_callback(int cpu, struct pt_regs *regs) @@ -46,6 +68,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs) #endif crash_save_cpu(regs, cpu); + /* + * VMCLEAR vmcss loaded on all cpus if needed. + */ + cpu_emergency_clear_loaded_vmcss(); + /* Disable VMX or SVM if needed. * * We need to disable virtualization on all CPUs. @@ -88,6 +115,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs) kdump_nmi_shootdown_cpus(); + /* + * VMCLEAR vmcss loaded on this cpu if needed. + */ + cpu_emergency_clear_loaded_vmcss(); + /* Booting kdump kernel with VMX or SVM enabled won't work, * because (among other limitations) we can't disable paging * with the virt flags. -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html