Re: [Xen-devel] [v7][RFC][PATCH 06/13] hvmloader/ram: check if guest memory is out of reserved device memory maps

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.11.14 at 02:26, <tiejun.chen@xxxxxxxxx> wrote:
>> > So without lookuping devices[i], how can we call func() for each sbdf as
>>> you mentioned?
>>
>> You've got both rmrr and bdf in the body of for_each_rmrr_device().
>> After all - as I said - you just open-coded it.
>>
> 
> Yeah, so change this again,
> 
> int intel_iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
> {
>      struct acpi_rmrr_unit *rmrr;
>      int rc = 0;
>      unsigned int i;
>      u16 bdf;
> 
>      for_each_rmrr_device ( rmrr, bdf, i )
>      {
>          rc = func(PFN_DOWN(rmrr->base_address),
>                             PFN_UP(rmrr->end_address) -
>                              PFN_DOWN(rmrr->base_address),
>                             PCI_SBDF(rmrr->segment, bdf),
>                            ctxt);
>          /* Hit this entry so just go next. */
>          if ( rc == 1 )
>              i = rmrr->scope.devices_cnt;
>          else if ( rc < 0 )
>              return rc;
>      }
> 
>      return rc;
> }

Better. Another improvement would be make it not depend on the
internal workings of for_each_rmrr_device()... And in any case you
should not special case 1 - just return when rc is negative and skip
the rest of the current RMRR when it's positive. And of course make
the function's final return value predictable.

Jan


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