On Wed, Sep 2, 2015 at 11:50 AM, Mark Rutland <mark.rutland@xxxxxxx> wrote:
>
> When VCPU #0 exits (e.g. due to KVM_EXIT_SYSTEM_EVENT), it sends
> SIGKVMEXIT to all other VCPUs, waits for them to exit, then tears down
> any remaining context. The signalling of SIGKVMEXIT is critical to
> forcing VCPUs to shut down in response to a system event (e.g. PSCI
> SYSTEM_OFF).
>
> VCPUs other that VCPU #0 simply exit in kvm_cpu_thread without forcing
> other CPUs to shut down. Thus if a system event is taken on a VCPU other
> than VCPU #0, the remaining CPUs are left online. This results in KVM
> tool not exiting as expected when a system event is taken on a VCPU
> other than VCPU #0 (as may happen if the guest panics).
>
> Fix this by signalling SIGKVMEXIT to VCPU #0 when a system event is
> taken on other CPUs, so that it may tear things down as usual.
>
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> kvm-cpu.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/kvm-cpu.c b/kvm-cpu.c
> index 5d90664..f47e3db 100644
> --- a/kvm-cpu.c
> +++ b/kvm-cpu.c
> @@ -166,13 +166,20 @@ int kvm_cpu__start(struct kvm_cpu *cpu)
> * treat all system events as shutdown request.
> */
> switch (cpu->kvm_run->system_event.type) {
> - case KVM_SYSTEM_EVENT_RESET:
> - /* Fall through for now */
> - case KVM_SYSTEM_EVENT_SHUTDOWN:
> - goto exit_kvm;
> default:
> pr_warning("unknown system event type %d",
> cpu->kvm_run->system_event.type);
> + /* fall through for now */
> + case KVM_SYSTEM_EVENT_RESET:
> + /* Fall through for now */
> + case KVM_SYSTEM_EVENT_SHUTDOWN:
> + /*
> + * Ensure that VCPU #0 tears everything down if
> + * the event was taken on a different VCPU.
> + */
> + if (cpu->cpu_id != 0)
> + pthread_kill(cpu->kvm->cpus[0]->thread,
> + SIGKVMEXIT);
Could we use kvm_cpu__reboot() instead ?
That sends SIGKVMEXIT to all the VCPUs, and is used by the other
paths which trigger a reboot/shutdown.
Suzuki
--
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
