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

[Tianrui Zhao]

在 2023年06月05日 21:03, bibo, mao 写道:
> 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@xxxxxxxxxxx>
> > ---
> >   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?
We do not handle ready_for_interrupt_injection when vcpu exit in 
qemu/kvm, and I will remove it.

Thanks
Tianrui Zhao
> > +
> > +	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
Thanks, this comment should contain more information, I will fix it.

Thanks
Tianrui Zhao
> > +		++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;