Re: [PATCH V3 09/23] xen/dm: Make x86's DM feature common

[Oleksandr <olekstysh@xxxxxxxxx>]

On 07.12.20 14:08, Jan Beulich wrote:

Hi Jan.

> On 30.11.2020 11:31, Oleksandr Tyshchenko wrote:
> > From: Julien Grall <julien.grall@xxxxxxx>
> >
> > As a lot of x86 code can be re-used on Arm later on, this patch
> > splits devicemodel support into common and arch specific parts.
> >
> > The common DM feature is supposed to be built with IOREQ_SERVER
> > option enabled (as well as the IOREQ feature), which is selected
> > for x86's config HVM for now.
> >
> > Also update XSM code a bit to let DM op be used on Arm.
> >
> > This support is going to be used on Arm to be able run device
> > emulator outside of Xen hypervisor.
> >
> > Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
> > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> >
> > ---
> > Please note, this is a split/cleanup/hardening of Julien's PoC:
> > "Add support for Guest IO forwarding to a device emulator"
> >
> > Changes RFC -> V1:
> >     - update XSM, related changes were pulled from:
> >       [RFC PATCH V1 04/12] xen/arm: Introduce arch specific bits for IOREQ/DM 
> > features
> >
> > Changes V1 -> V2:
> >     - update the author of a patch
> >     - update patch description
> >     - introduce xen/dm.h and move definitions here
> >
> > Changes V2 -> V3:
> >     - no changes
> And my concern regarding the common vs arch nesting also hasn't
> changed.

I am sorry, I might misread your comment, but I failed to see any 
obvious to me request(s) for changes.
I have just re-read previous discussion...
So the question about considering doing it the other way around (top 
level dm-op handling arch-specific
and call into e.g. ioreq_server_dm_op() for otherwise unhandled ops) is 
exactly a concern which I should have addressed?
--
Regards,

Oleksandr Tyshchenko