Re: [PATCH v12 22/31] LoongArch: KVM: Implement handle idle exception

["bibo, mao" <maobibo@loongson.cn>]

Reviewed-by: Bibo, Mao <maobibo@loongson.cn>

在 2023/5/30 09:52, Tianrui Zhao 写道:
> Implement kvm handle LoongArch vcpu idle exception, using kvm_vcpu_block
> to emulate it.
> 
> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
> ---
>  arch/loongarch/kvm/exit.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
> index bd33fe0c6424..3fdb42939a05 100644
> --- a/arch/loongarch/kvm/exit.c
> +++ b/arch/loongarch/kvm/exit.c
> @@ -188,3 +188,23 @@ int _kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  
>  	return er;
>  }
> +
> +int _kvm_emu_idle(struct kvm_vcpu *vcpu)
> +{
> +	++vcpu->stat.idle_exits;
> +	trace_kvm_exit_idle(vcpu, KVM_TRACE_EXIT_IDLE);
> +
> +	if (!kvm_arch_vcpu_runnable(vcpu)) {
> +		/*
> +		 * Switch to the software timer before halt-polling/blocking as
> +		 * the guest's timer may be a break event for the vCPU, and the
> +		 * hypervisor timer runs only when the CPU is in guest mode.
> +		 * Switch before halt-polling so that KVM recognizes an expired
> +		 * timer before blocking.
> +		 */
> +		kvm_save_timer(vcpu);
> +		kvm_vcpu_block(vcpu);
> +	}
> +
> +	return EMULATE_DONE;
> +}