Re: [PATCH v1 6/9] asm-generic: move some parts of Arm's domain_build.h to asm-generic header

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 1/27/25 12:23 PM, Jan Beulich wrote:

> On 08.01.2025 12:13, Oleksii Kurochko wrote:
> > Nothing changed. Only some functions declaration are moved to asm-generic
> > header as they are expected to be used by common code of domain builing or
> > dom0less.
> >
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> > ---
> >  xen/arch/arm/include/asm/domain_build.h | 19 ++----------
> >  xen/include/asm-generic/domain-build.h  | 41 +++++++++++++++++++++++++
> >  2 files changed, 43 insertions(+), 17 deletions(-)
> >  create mode 100644 xen/include/asm-generic/domain-build.h
> >       
> Again I question this movement under this name. "Domain building" is a pretty
> generic thing, yes, but what you move would e.g. be entirely inapplicable on
> x86 (as it is now). For example ...
>
> > --- /dev/null
> > +++ b/xen/include/asm-generic/domain-build.h
> > @@ -0,0 +1,41 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_GENERIC_DOMAIN_BUILD_H__
> > +#define __ASM_GENERIC_DOMAIN_BUILD_H__
> > +
> > +#include <xen/types.h>
> > +
> > +struct domain;
> > +struct page_info;
> > +struct kernel_info;
> > +struct membanks;
> > +
> > +typedef bool (*alloc_domheap_mem_cb)(struct domain *d, struct page_info *pg,
> > +                                     unsigned int order, void *extra);
> > +bool allocate_domheap_memory(struct domain *d, paddr_t tot_size,
> > +                             alloc_domheap_mem_cb cb, void *extra);
> > +
> > +bool allocate_bank_memory(struct kernel_info *kinfo, gfn_t sgfn,
> > +                          paddr_t tot_size);
> >       
> ... the term "bank" seems pretty closely tied to DT. Other stuff ...
>
> > +void allocate_memory(struct domain *d, struct kernel_info *kinfo);
> > +int construct_domain(struct domain *d, struct kernel_info *kinfo);
> > +int make_chosen_node(const struct kernel_info *kinfo);
> > +int make_cpus_node(const struct domain *d, void *fdt);
> > +int make_hypervisor_node(struct domain *d, const struct kernel_info *kinfo,
> > +                         int addrcells, int sizecells);
> > +int make_memory_node(const struct kernel_info *kinfo, int addrcells,
> > +                     int sizecells, const struct membanks *mem);
> > +int make_timer_node(const struct kernel_info *kinfo);
> >       
> ... here also falls in this category. Stuff like this may well live
> under asm-generic/, but the file name chosen then needs to reflect
> constraints.
>     
Unfortunately, at least at the moment, this is not applicable to x86.

Partially, domain_build.h was chosen to have less changes in Arm code.

Would it be better to use domain-build-dt.h?

~ Oleksii