Re: [PATCH v8 0/7] xen: introduce CONFIG_SYSCTL

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Heads up, I intend to commit this series shortly as it has been
thoroughly reviewed by multiple people and has been on the list for a
long time now.


On Fri, 11 Jul 2025, 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_SYSCTL. Different
> options will be covered in different patch serie.
> 
> Features, like LIVEPATCH, Overlay DTB, which fully rely on sysctl 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)
> 
> ---
> Commit "xen/x86: remove "depends on !PV_SHIM_EXCLUSIVE"" and commit "
> xen/sysctl: wrap around sysctl hypercall" shall be commited together.
> ---
> Penny Zheng (6):
>   xen/xsm: wrap around xsm_sysctl with CONFIG_SYSCTL
>   xen/sysctl: wrap around XEN_SYSCTL_readconsole
>   xen/sysctl: wrap around XEN_SYSCTL_page_offline_op
>   xen/sysctl: wrap around XEN_SYSCTL_scheduler_op
>   xen/sysctl: wrap around arch-specific arch_do_sysctl
>   xen/x86: remove "depends on !PV_SHIM_EXCLUSIVE"
> 
> Stefano Stabellini (1):
>   xen/sysctl: wrap around sysctl hypercall
> 
>  xen/arch/arm/Kconfig                  |  1 +
>  xen/arch/arm/Makefile                 |  2 +-
>  xen/arch/arm/sysctl.c                 |  2 --
>  xen/arch/riscv/stubs.c                |  2 +-
>  xen/arch/x86/Kconfig                  |  4 ----
>  xen/arch/x86/Makefile                 |  2 +-
>  xen/arch/x86/configs/pvshim_defconfig |  5 +----
>  xen/arch/x86/hvm/Kconfig              |  1 -
>  xen/arch/x86/psr.c                    | 18 ++++++++++++++++++
>  xen/arch/x86/sysctl.c                 |  2 --
>  xen/common/Kconfig                    |  6 +++++-
>  xen/common/Makefile                   |  2 +-
>  xen/common/page_alloc.c               |  2 ++
>  xen/common/sched/arinc653.c           |  6 ++++++
>  xen/common/sched/core.c               |  2 ++
>  xen/common/sched/credit.c             |  4 ++++
>  xen/common/sched/credit2.c            |  4 ++++
>  xen/common/sched/private.h            |  4 ++++
>  xen/drivers/char/console.c            |  2 ++
>  xen/drivers/video/Kconfig             |  2 +-
>  xen/include/hypercall-defs.c          |  8 ++++++--
>  xen/include/xsm/xsm.h                 | 18 ++++++++++++++++++
>  xen/xsm/dummy.c                       |  6 ++++++
>  xen/xsm/flask/hooks.c                 | 14 ++++++++++++++
>  24 files changed, 98 insertions(+), 21 deletions(-)
> 
> -- 
> 2.34.1
>