[PATCH 1/5] arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option

[Peter Maydell]

On 27 November 2014 at 18:40, Christoffer Dall
<christoffer.dall at linaro.org> wrote:
> The implementation of KVM_ARM_VCPU_INIT is currently not doing what
> userspace expects, namely making sure that a vcpu which may have been
> turned off using PSCI is returned to its initial state, which would be
> powered on if userspace does not set the KVM_ARM_VCPU_POWER_OFF flag.
>
> Implment the expected functionality and clarify the ABI.

("Implement", if you have to respin.)

> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 9e193c8..4dcc8c2 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -663,6 +663,8 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
>          */
>         if (__test_and_clear_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
>                 vcpu->arch.pause = true;
> +       else
> +               vcpu->arch.pause = false;

Out of curiosity, why do we have to test-and-clear the bit rather than
just testing it?

thanks
-- PMM