Re: [PATCH v12 26/31] LoongArch: KVM: Implement kvm exception vector

[Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>]

在 2023年06月06日 15:00, Youling Tang 写道:
> On 05/30/2023 09:52 AM, Tianrui Zhao wrote:
> > Implement kvm exception vector, using _kvm_fault_tables array to save
> > the handle function pointer and it is used when vcpu handle exit.
> >
> > Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
> > ---
> >  arch/loongarch/kvm/exit.c | 48 +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 48 insertions(+)
> >
> > diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
> > index 10f9922a7e76..625045fc95c8 100644
> > --- a/arch/loongarch/kvm/exit.c
> > +++ b/arch/loongarch/kvm/exit.c
> > @@ -657,3 +657,51 @@ static int _kvm_handle_fpu_disabled(struct 
> > kvm_vcpu *vcpu)
> >      kvm_own_fpu(vcpu);
> >      return RESUME_GUEST;
> >  }
> > +
> > +/*
> > + * Loongarch KVM callback handling for not implemented guest exiting
> > + */
> > +static int _kvm_fault_ni(struct kvm_vcpu *vcpu)
> > +{
> > +    unsigned long estat, badv;
> > +    unsigned int exccode, inst;
> > +
> > +    /*
> > +     *  Fetch the instruction.
> > +     */
> > +    badv = vcpu->arch.badv;
> > +    estat = vcpu->arch.host_estat;
> > +    exccode = (estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
> > +    inst = vcpu->arch.badi;
> > +    kvm_err("Exccode: %d PC=%#lx inst=0x%08x BadVaddr=%#lx 
> > estat=%#lx\n",
> > +            exccode, vcpu->arch.pc, inst, badv, read_gcsr_estat());
> > +    kvm_arch_vcpu_dump_regs(vcpu);
> > +    vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
> > +
> > +    return RESUME_HOST;
> > +}
> > +
> > +static exit_handle_fn _kvm_fault_tables[EXCCODE_INT_START] = {
> > +    [EXCCODE_TLBL]        = _kvm_handle_read_fault,
> > +    [EXCCODE_TLBI]        = _kvm_handle_read_fault,
> > +    [EXCCODE_TLBNR]        = _kvm_handle_read_fault,
> > +    [EXCCODE_TLBNX]        = _kvm_handle_read_fault,
> > +    [EXCCODE_TLBS]        = _kvm_handle_write_fault,
> > +    [EXCCODE_TLBM]        = _kvm_handle_write_fault,
> > +    [EXCCODE_FPDIS]        = _kvm_handle_fpu_disabled,
> > +    [EXCCODE_GSPR]        = _kvm_handle_gspr,
> > +};
> It can be modified as follows and remove _kvm_init_fault().
>
> static exit_handle_fn _kvm_fault_tables[EXCCODE_INT_START] = {
>     [0 ... EXCCODE_INT_START - 1]    = _kvm_fault_ni,
>
>     [EXCCODE_TLBL]            = _kvm_handle_read_fault,
>     [EXCCODE_TLBI]            = _kvm_handle_read_fault,
>     [EXCCODE_TLBNR]            = _kvm_handle_read_fault,
>     [EXCCODE_TLBNX]            = _kvm_handle_read_fault,
>     [EXCCODE_TLBS]            = _kvm_handle_write_fault,
>     [EXCCODE_TLBM]            = _kvm_handle_write_fault,
>     [EXCCODE_FPDIS]            = _kvm_handle_fpu_disabled,
>     [EXCCODE_GSPR]            = _kvm_handle_gspr,
> };
>
> Thanks,
> Youling
Thanks, this method can simplify the code, I will fix it.

Thanks
Tianrui Zhao
> > +
> > +int _kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
> > +{
> > +    return _kvm_fault_tables[fault](vcpu);
> > +}
> > +
> > +void _kvm_init_fault(void)
> > +{
> > +    int i;
> > +
> > +    for (i = 0; i < EXCCODE_INT_START; i++)
> > +        if (!_kvm_fault_tables[i])
> > +            _kvm_fault_tables[i] = _kvm_fault_ni;
> > +}