Messages in this thread Patch in this message | | | Date | Thu, 20 Apr 2017 04:16:49 -0700 | From | tip-bot for Tiantian Feng <> | Subject | [tip:x86/boot] x86/reboot: Turn off KVM when halting a CPU |
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Commit-ID: fba4f472b33aa81ca1836f57d005455261e9126f Gitweb: http://git.kernel.org/tip/fba4f472b33aa81ca1836f57d005455261e9126f Author: Tiantian Feng <fengtiantian@huawei.com> AuthorDate: Wed, 19 Apr 2017 18:18:39 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 20 Apr 2017 10:06:57 +0200
x86/reboot: Turn off KVM when halting a CPU
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 <fengtiantian@huawei.com> Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> [ Rewritten commit message. ] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/20170419161839.30550-1-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- 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 d3c66a1..9d7223c 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(); }
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