Re: [RFC v6 03/13] hw/alpha/typhoon: Mark all IOMMUTLBEntry as IOMMU_IOTLB_NONE type

[Peter Xu <peterx@redhat.com>]

On Wed, Aug 26, 2020 at 04:36:41PM +0200, Eugenio Pérez wrote:
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>  hw/alpha/typhoon.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/alpha/typhoon.c b/hw/alpha/typhoon.c
> index 29d44dfb06..b1e6c4e929 100644
> --- a/hw/alpha/typhoon.c
> +++ b/hw/alpha/typhoon.c
> @@ -615,6 +615,7 @@ static bool make_iommu_tlbe(hwaddr taddr, hwaddr mask, IOMMUTLBEntry *ret)
>          .translated_addr = taddr,
>          .addr_mask = mask,
>          .perm = IOMMU_RW,
> +        .type = IOMMU_IOTLB_NONE,

IMHO we don't need to touch all the IOMMUTLBEntry users, but only the callers
of memory_region_notify_iommu*().  We should also comment at the type field
that it's meaningless except when used for IOMMU notifications, because these
are really two different things: IOMMUTLBEntry was originally a translated
entry out of IOMMU hardware, so in those case it does not need a "type" field.

To make it clearer (depending on your preference...), we can introduce
IOMMUTLBEvent to be:

  struct IOMMUTLBEvent {
    IOMMUTLBEntry entry;
    IOMMUTLBType type;
  };

Then it'll be clear on which is which.  Though you'll need to touch more things
(all the callers and all the registerered notifiers).

Thanks,

-- 
Peter Xu