Re: [Xen-devel] [PATCH v2 2/5] iommu: introduce dom0-iommu option

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 02.08.18 at 09:46, <kevin.tian@xxxxxxxxx> wrote:
>>  From: Roger Pau Monne [mailto:roger.pau@xxxxxxxxxx]
>> Sent: Wednesday, August 1, 2018 7:04 PM
>> --- a/docs/misc/xen-command-line.markdown
>> +++ b/docs/misc/xen-command-line.markdown
>> @@ -1150,12 +1150,18 @@ detection of systems known to misbehave
>> upon accesses to that port.
>> 
>>  > `dom0-passthrough`
>> 
>> +> **WARNING: This command line option is deprecated, and superseded
>> by
>> +> _dom0-iommu=none_ - using both options in combination is
>> undefined.**
>> +
> 
> in patch description you said 'supersede'... is it better to say that
> new dom0_iommu is favored if both options are specified than
> saying 'undefined'?

That would complicate handling (perhaps just slightly, but anyway),
since we'd have to maintain a second boolean. Without that the
order on the command line determines behavior. (And I see that in
the end you've figured that out.)

>> @@ -1198,6 +1204,32 @@ detection of systems known to misbehave upon
>> accesses to that port.
>> 
>>  >> Enable IOMMU debugging code (implies `verbose`).
>> 
>> +### dom0-iommu
>> +> `= List of [ none | strict | relaxed ]`
>> +
>> +> Sub-options are of boolean kind and can be prefixed with `no-` to effect
>> the
>> +> inverse meaning.
> 
> not important comment, but doesn't "no-none" sound weird? :-)

Only positive (true) values should be permitted for I think all of
these. I didn't look at the patch yes, so perhaps that's already
the case.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel