Re: PML (Page Modification Logging) design for Xen

[Kai Huang <kai.huang@linux.intel.com>]

On 03/24/2015 04:14 PM, Jan Beulich wrote:
>>>> On 24.03.15 at 09:06, <kai.huang@linux.intel.com> wrote:
>> On 03/24/2015 03:53 PM, Jan Beulich wrote:
>>>    The command line
>>> option parsing is (and should be) independent of the chosen
>>> default anyway, i.e. overrides in either direction should be
>>> possible.
>> While the parse_ept_param function does support "ept=pml" and
>> "ept=no-pml" both, I think in the comments of the function we should
>> explicitly tell whether to use "ept=pml" (in case PML is off by
>> default), or "ept=no-pml" (in case PML is on by default), otherwise
>> "ept=pml,no-pml" is legal but obviously it doesn't make any sense (and
>> looks this issue also exists in parse_iommu_param?).
> While "ept=pml,no-pml" makes little sense, there's nothing wrong
> with allowing it. "ept=pml ept=no-pml" may in fact make sense,
> when wanting to override a setting e.g. in an EFI config file on
> the command (or grub) line. IOW don't lose time on preventing
> non-sense option combinations if the resulting settings
> nevertheless are valid / meaningful.
Hmm. Reasonable indeed. Thanks.

Thanks,
-Kai
>
> Jan
>