Re: [PATCH v2 3/3] hw/intc: Fix LoongArch ipi device emulation

[yangxiaojuan]

在 2022/9/29 上午10:42, Richard Henderson 写道:

> On
>       9/26/22 23:12, Xiaojuan Yang wrote:
>       
> > In ipi_send function, it should not to set
> >         irq before
> >         
> >         writing data to dest cpu iocsr space, as the irq will
> >         
> >         trigger after data writing.
> >         
> >         
> >         Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
> >         
> >         ---
> >         
> >           hw/intc/loongarch_ipi.c | 1 -
> >         
> >           1 file changed, 1 deletion(-)
> >         
> >         
> >         diff --git a/hw/intc/loongarch_ipi.c b/hw/intc/loongarch_ipi.c
> >         
> >         index 4f3c58f872..aa4bf9eb74 100644
> >         
> >         --- a/hw/intc/loongarch_ipi.c
> >         
> >         +++ b/hw/intc/loongarch_ipi.c
> >         
> >         @@ -88,7 +88,6 @@ static void ipi_send(uint64_t val)
> >         
> >               cs = qemu_get_cpu(cpuid);
> >         
> >               cpu = LOONGARCH_CPU(cs);
> >         
> >               env = &cpu->env;
> >         
> >         -    loongarch_cpu_set_irq(cpu, IRQ_IPI, 1);
> >         
> >               address_space_stl(&env->address_space_iocsr,
> >         0x1008,
> >         
> >                                 data, MEMTXATTRS_UNSPECIFIED, NULL);
> >         
> >           
>       
>       Did you mean to move the call below the set?
>       
>       Otherwise, where does the irq get raised?
>       
>       
>     
    When call this function
      'address_space_stl(&env->address_space_iocsr, 0x1008, ...
      ...)',  it will trigger  loongarch_ipi_writel(), the addr arg is
      0x1008 ('CORE_SET_OFFSET'), and qemu_irq_raise will be called in
      this case.
    
    Thanks.
    Xiaojuan Yang