Re: [PATCH v1 00/25] Introduce CONFIG_DOMCTL

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.08.2025 11:47, Penny Zheng wrote:
> It can be beneficial for some dom0less systems to further reduce Xen footprint
> via disabling some hypercalls handling code, which may not to be used &
> required in such systems. Each hypercall has a separate option to keep
> configuration flexible.
> 
> Options to disable hypercalls:
> - sysctl
> - domctl
> - hvm
> - physdev
> - platform
> 
> This patch serie is only focusing on introducing CONFIG_DOMCTL. Different
> options will be covered in different patch serie.
> 
> Features, like VM event, or paging log-dirty support, which fully rely on
> domctl op, will be wrapped with CONFIG_SYSCTL, to reduce Xen footprint as
> much as possible.
> 
> It is derived from Stefano Stabellini's commit "xen: introduce kconfig 
> options to
> disable hypercalls"(
> https://lore.kernel.org/xen-devel/20241219092917.3006174-1-Sergiy_Kibrik@xxxxxxxx)
> 
> Penny Zheng (25):
>   xen/x86: move domctl.o out of PV_SHIM_EXCLUSIVE
>   xen/x86: consolidate vram tracking support
>   xen/x86: complement PG_log_dirty wrapping
>   xen: consolidate CONFIG_VM_EVENT
>   xen: introduce CONFIG_DOMCTL
>   xen/domctl: provide stub for domctl_lock_{acquire,release}
>   xen/domctl: wrap around XEN_DOMCTL_pausedomain
>   xen/domctl: wrap around XEN_DOMCTL_soft_reset
>   xen/domctl: wrap around XEN_DOMCTL_destroydomain
>   xen/domctl: wrap around XEN_DOMCTL_setnodeaffinity
>   xen/domctl: wrap around XEN_DOMCTL_{getvcpuaffinity,setvcpuaffinity}
>   xen/domctl: wrap around XEN_DOMCTL_scheduler_op
>   xen/domctl: wrap around XEN_DOMCTL_getvcpucontext
>   xen/domctl: wrap around XEN_DOMCTL_{irq_permission,iomem_permission}
>   xen/domctl: wrap around XEN_DOMCTL_settimeoffset
>   xen/domctl: wrap around XEN_DOMCTL_set_target
>   xen: add stub for XEN_DOMCTL_getdomaininfo
>   xen/domctl: wrap around XEN_DOMCTL_set_access_required
>   xen: make CONFIG_VM_EVENT depend on DOMCTL
>   xen/domctl: wrap around XEN_DOMCTL_set_virq_handler
>   xen/domctl: wrap aound iommu-related domctl op
>   xen/domctl: wrap around XEN_DOMCTL_{get,set}_paging_mempool_size
>   xen/x86: make CONFIG_X86_PSR depend on SYSCTL || DOMCTL
>   xen/domctl: wrap around arch-specific domctl op
>   xen/domctl: wrap around domctl hypercall

Hmm, I should have remembered to Cc you on this [1] reply of mine to Jiqian.
It applies here as well.

Jan

[1] https://lists.xen.org/archives/html/xen-devel/2025-07/msg01884.html