Re: [PATCH v4 04/11] xen: introduce domain-layout.h with common domain_use_host_layout()

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 5/4/26 2:59 PM, Jan Beulich wrote:
> On 28.04.2026 16:33, Oleksii Kurochko wrote:
> > domain_use_host_layout() is not architecture-specific and may be needed
> > on x86 [1]. Replace the ARM-specific macro in asm/domain.h with a common
> > static inline in a new dedicated header, xen/domain-layout.h.
> >
> > xen/domain.h would be the natural home, but placing it there would
> > require including xen/paging.h (for paging_mode_translate()) and
> > xen/sched.h (for is_hardware_domain()), which would introduce circular
> > dependencies. A separate header that callers opt into avoids this.
> >
> > Adjust the implementation to take paging_mode_translate() into account
> > so it works correctly for all architectures, including x86. Some extra
> > details about implementation [2] and [3].
> >
> > [1] 
> > https://lore.kernel.org/xen-devel/alpine.DEB.2.22.394.2602161038120.359097@ubuntu-linux-20-04-desktop/
> > [2] 
> > https://lore.kernel.org/xen-devel/alpine.DEB.2.22.394.2602271742400.3148344@ubuntu-linux-20-04-desktop/
> > [3] 
> > https://lore.kernel.org/xen-devel/alpine.DEB.2.22.394.2602271750190.3148344@ubuntu-linux-20-04-desktop/
> >
> > Suggested-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> With the SPDX tag added as indicated by Luca:
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
Thanks.

> One further minor remark:
>
> > --- /dev/null
> > +++ b/xen/include/xen/domain-layout.h
> > @@ -0,0 +1,27 @@
> > +#ifndef __XEN_DOMAIN_LAYOUT_H__
> > +#define __XEN_DOMAIN_LAYOUT_H__
> > +
> > +#include <xen/domain.h>
> This isn't really needed. It is ...
>
> > +#include <xen/paging.h>
> > +#include <xen/sched.h>
> ... included by this one anyway (pretty much unavoidably right now, I
> guess).
Then it will be needed to re-order them.

Do you want to put the comment above xen/sched.h:

/*
 * Ensure xen/sched.h is included before xen/paging.h, since paging.h 
depends
 * on xen/domain.h, which is pulled in via sched.h.
 */
#include <xen/sched.h>
#include <xen/paging.h>

or just add this to commit message instead?

~ Oleksii

> Jan