Re: [PATCH v12 08/31] LoongArch: KVM: Implement vcpu handle exit interface

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

在 2023/5/30 09:52, Tianrui Zhao 写道:
> Implement vcpu handle exit interface, getting the exit code by ESTAT
> register and using kvm exception vector to handle it.
> 
> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
> ---
>  arch/loongarch/kvm/vcpu.c | 46 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 46 insertions(+)
> 
> diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
> index eca8b96a3e6e..ddea480fa5b0 100644
> --- a/arch/loongarch/kvm/vcpu.c
> +++ b/arch/loongarch/kvm/vcpu.c
> @@ -55,6 +55,52 @@ static void kvm_pre_enter_guest(struct kvm_vcpu *vcpu)
>  	vcpu->arch.aux_inuse &= ~KVM_LARCH_CSR;
>  }
>  
> +/*
> + * Return 1 for resume guest and "<= 0" for resume host.
> + */
> +static int _kvm_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
> +{
> +	unsigned long exst = vcpu->arch.host_estat;
> +	u32 intr = exst & 0x1fff; /* ignore NMI */
> +	u32 exccode = (exst & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
> +	int ret = RESUME_GUEST;
> +
> +	vcpu->mode = OUTSIDE_GUEST_MODE;
> +
> +	/* Set a default exit reason */
> +	run->exit_reason = KVM_EXIT_UNKNOWN;
> +	run->ready_for_interrupt_injection = 1;
Is ready_for_interrupt_injection used in qemu or kvm for LoongArch?

> +
> +	local_irq_enable();
> +	guest_state_exit_irqoff();
> +
> +	trace_kvm_exit(vcpu, exccode);
> +	if (exccode) {
> +		ret = _kvm_handle_fault(vcpu, exccode);
> +	} else {
> +		WARN(!intr, "suspicious vm exiting");
how about comments like this?
  WARN(!intr, "vm exiting with suspicious irq \n") 

Regards
Bibo, Mao
> +		++vcpu->stat.int_exits;
> +	}
> +
> +	cond_resched();
> +	local_irq_disable();
> +
> +	if (ret == RESUME_HOST)
> +		return ret;
> +
> +	/* Only check for signals if not already exiting to userspace */
> +	if (signal_pending(current)) {
> +		vcpu->run->exit_reason = KVM_EXIT_INTR;
> +		++vcpu->stat.signal_exits;
> +		return -EINTR;
> +	}
> +
> +	kvm_pre_enter_guest(vcpu);
> +	trace_kvm_reenter(vcpu);
> +	guest_state_enter_irqoff();
> +	return RESUME_GUEST;
> +}
> +
>  int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
>  {
>  	unsigned long timer_hz;