From 2340b62f77c782c305e6ae7748675a638436d1ef Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Mon, 17 Nov 2008 19:03:23 -0200 Subject: kdump: forcibly disable VMX and SVM on machine_crash_shutdown() We need to disable virtualization extensions on all CPUs before booting the kdump kernel, otherwise the kdump kernel booting will fail, and rebooting after the kdump kernel did its task may also fail. We do it using cpu_emergency_vmxoff() and cpu_emergency_svm_disable(), that should always work, because those functions check if the CPUs support SVM or VMX before doing their tasks. Signed-off-by: Eduardo Habkost Signed-off-by: Avi Kivity --- arch/x86/kernel/crash.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index d84a852e4cd..c689d19e35a 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -26,6 +26,7 @@ #include #include #include +#include #include @@ -49,6 +50,15 @@ static void kdump_nmi_callback(int cpu, struct die_args *args) #endif crash_save_cpu(regs, cpu); + /* Disable VMX or SVM if needed. + * + * We need to disable virtualization on all CPUs. + * Having VMX or SVM enabled on any CPU may break rebooting + * after the kdump kernel has finished its task. + */ + cpu_emergency_vmxoff(); + cpu_emergency_svm_disable(); + disable_local_APIC(); } @@ -80,6 +90,14 @@ void native_machine_crash_shutdown(struct pt_regs *regs) local_irq_disable(); kdump_nmi_shootdown_cpus(); + + /* Booting kdump kernel with VMX or SVM enabled won't work, + * because (among other limitations) we can't disable paging + * with the virt flags. + */ + cpu_emergency_vmxoff(); + cpu_emergency_svm_disable(); + lapic_shutdown(); #if defined(CONFIG_X86_IO_APIC) disable_IO_APIC(); -- cgit v1.2.3