Re: [PATCH v4 00/20] xen: introduce CONFIG_SYSCTL

[Jan Beulich <jbeulich@xxxxxxxx>]

On 28.05.2025 11:16, 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 based on Stefano Stabellini's commit "xen: introduce kconfig options to
> disable hypercalls"(
> https://lore.kernel.org/xen-devel/20241219092917.3006174-1-Sergiy_Kibrik@xxxxxxxx)

"Based on" can have two meanings - another series is a prereq, or your work
is derived from earlier work. Would be nice to be unambiguous, as in the
former case it would be unclear at what point (parts of) this series can go
in. You also will want to see about chasing acks for some of the patches
which are otherwise ready (or perhaps merely depend on a final version of
patch 04).

Jan

> Penny Zheng (18):
>   xen/pmstat: consolidate code into pmstat.c
>   xen: make avail_domheap_pages() inlined into get_outstanding_claims()
>   xen/x86: remove "depends on !PV_SHIM_EXCLUSIVE"
>   xen/xsm: wrap around xsm_sysctl with CONFIG_SYSCTL
>   xen/sysctl: wrap around XEN_SYSCTL_readconsole
>   xen/sysctl: make CONFIG_TRACEBUFFER depend on CONFIG_SYSCTL
>   xen/sysctl: wrap around XEN_SYSCTL_sched_id
>   xen/sysctl: wrap around XEN_SYSCTL_perfc_op
>   xen/sysctl: wrap around XEN_SYSCTL_lockprof_op
>   xen/pmstat: introduce CONFIG_PM_OP
>   xen/sysctl: introduce CONFIG_PM_STATS
>   xen/sysctl: wrap around XEN_SYSCTL_page_offline_op
>   xen/sysctl: wrap around XEN_SYSCTL_cpupool_op
>   xen/sysctl: wrap around XEN_SYSCTL_scheduler_op
>   xen/sysctl: wrap around XEN_SYSCTL_physinfo
>   xen/sysctl: make CONFIG_COVERAGE depend on CONFIG_SYSCTL
>   xen/sysctl: make CONFIG_LIVEPATCH depend on CONFIG_SYSCTL
>   xen/sysctl: wrap around arch-specific arch_do_sysctl
> 
> Stefano Stabellini (2):
>   xen: introduce CONFIG_SYSCTL
>   xen/sysctl: wrap around sysctl hypercall
> 
>  xen/Kconfig.debug                            |   2 +-
>  xen/arch/arm/Kconfig                         |   1 +
>  xen/arch/arm/Makefile                        |   2 +-
>  xen/arch/riscv/stubs.c                       |   2 +
>  xen/arch/x86/Kconfig                         |   6 +-
>  xen/arch/x86/Makefile                        |   2 +-
>  xen/arch/x86/acpi/cpu_idle.c                 |   2 +
>  xen/arch/x86/acpi/cpufreq/hwp.c              |   6 +
>  xen/arch/x86/acpi/cpufreq/powernow.c         |   4 +
>  xen/arch/x86/configs/pvshim_defconfig        |   6 +
>  xen/arch/x86/hvm/Kconfig                     |   1 -
>  xen/arch/x86/psr.c                           |  18 +
>  xen/common/Kconfig                           |  29 +-
>  xen/common/Makefile                          |   2 +-
>  xen/common/page_alloc.c                      |  55 +-
>  xen/common/perfc.c                           |   2 +
>  xen/common/sched/arinc653.c                  |   6 +
>  xen/common/sched/core.c                      |   4 +
>  xen/common/sched/cpupool.c                   |   8 +
>  xen/common/sched/credit.c                    |   4 +
>  xen/common/sched/credit2.c                   |   4 +
>  xen/common/sched/private.h                   |   4 +
>  xen/common/spinlock.c                        |   2 +
>  xen/common/sysctl.c                          |   4 +-
>  xen/drivers/acpi/Makefile                    |   3 +-
>  xen/drivers/acpi/pm-op.c                     | 397 +++++++++++++
>  xen/drivers/acpi/pmstat.c                    | 559 ++++++-------------
>  xen/drivers/char/console.c                   |   2 +
>  xen/drivers/cpufreq/cpufreq.c                |  31 +
>  xen/drivers/cpufreq/cpufreq_misc_governors.c |   2 +
>  xen/drivers/cpufreq/cpufreq_ondemand.c       |   2 +
>  xen/drivers/cpufreq/utility.c                | 204 -------
>  xen/drivers/video/Kconfig                    |   4 +-
>  xen/include/acpi/cpufreq/cpufreq.h           |   5 -
>  xen/include/acpi/cpufreq/processor_perf.h    |  14 +-
>  xen/include/hypercall-defs.c                 |   8 +-
>  xen/include/xen/mm.h                         |   1 -
>  xen/include/xsm/xsm.h                        |  18 +
>  xen/xsm/dummy.c                              |   6 +
>  xen/xsm/flask/hooks.c                        |  14 +
>  40 files changed, 798 insertions(+), 648 deletions(-)
>  create mode 100644 xen/drivers/acpi/pm-op.c
>