From: Tiantian Feng <fengtiantian@xxxxxxxxxx> A CPU in VMX root mode will ignore INIT signals and fail to bring up the APs after reboot. Therefore, on a panic we disable VMX on all CPUs before rebooting or triggering kdump. Do this when halting the machine as well, in case a firmware-level reboot does not perform a cold reset for all processors. Without doing this, rebooting the host may hang. Signed-off-by: Tiantian Feng <fengtiantian@xxxxxxxxxx> Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx> [Rewritten commit message. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index d3c66a15bbde..9d7223cad389 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -33,6 +33,7 @@ #include <asm/mce.h> #include <asm/trace/irq_vectors.h> #include <asm/kexec.h> +#include <asm/virtext.h> /* * Some notes on x86 processor bugs affecting SMP operation: @@ -162,6 +163,7 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs) if (raw_smp_processor_id() == atomic_read(&stopping_cpu)) return NMI_HANDLED; + cpu_emergency_vmxoff(); stop_this_cpu(NULL); return NMI_HANDLED; @@ -174,6 +176,7 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs) asmlinkage __visible void smp_reboot_interrupt(void) { ipi_entering_ack_irq(); + cpu_emergency_vmxoff(); stop_this_cpu(NULL); irq_exit(); } -- 2.9.3