Re: [RFC PATCH 3/4] hw/intc/gic: use MxTxAttrs to divine accessing CPU

[Philippe Mathieu-Daudé]

On 15/9/22 10:16, Richard Henderson wrote:
> On 9/14/22 17:09, Alex Bennée wrote:
> > Now that MxTxAttrs encodes a CPU we should use that to figure it out.
> > This solves edge cases like accessing via gdbstub or qtest.
> >
> > Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/124
> > ---
> >   hw/intc/arm_gic.c | 39 ++++++++++++++++++++++-----------------
> >   1 file changed, 22 insertions(+), 17 deletions(-)
> >
> > diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
> > index 492b2421ab..7feedac735 100644
> > --- a/hw/intc/arm_gic.c
> > +++ b/hw/intc/arm_gic.c
> > @@ -56,17 +56,22 @@ static const uint8_t gic_id_gicv2[] = {
> >       0x04, 0x00, 0x00, 0x00, 0x90, 0xb4, 0x2b, 0x00, 0x0d, 0xf0, 
> > 0x05, 0xb1
> >   };
> > -static inline int gic_get_current_cpu(GICState *s)
> > +static inline int gic_get_current_cpu(GICState *s, MemTxAttrs attrs)
> >   {
> > -    if (!qtest_enabled() && s->num_cpu > 1) {
> > -        return current_cpu->cpu_index;
> > -    }
> > -    return 0;
> > +    /*
> > +     * Something other than a CPU accessing the GIC would be a bug as
> > +     * would a CPU index higher than the GICState expects to be
> > +     * handling
> > +     */
> > +    g_assert(attrs.requester_cpu == 1);
>
> Better without "== 1" -- this field ought to be boolean.

Boolean so far, but this could get more types (such DMA...).
Maybe we could already add an enum definitions, i.e.:

typedef enum MemTxRequesterType {
  MEMTXATTRS_CPU,
  MEMTXATTRS_MSI,
} MemTxRequesterType;

and name the field MemTxAttrs::requester_type.