From: Tiantian Feng <fengtiant...@huawei.com> [ Upstream commit fba4f472b33aa81ca1836f57d005455261e9126f ]
A CPU in VMX root mode will ignore INIT signals and will 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 <fengtiant...@huawei.com> Signed-off-by: Xishi Qiu <qiuxi...@huawei.com> [ Rewritten commit message. ] Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: k...@vger.kernel.org Link: http://lkml.kernel.org/r/20170419161839.30550-1-pbonz...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Sasha Levin <alexander.le...@microsoft.com> --- 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 ca699677e288..ea217caa731c 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(); } -- 2.14.1
