[v4,0/6] x86/time: improvements to wallclock logic

Message

Roger Pau Monne Sept. 4, 2024, 3:31 p.m. UTC

Hello,

This series started as an attempt to change the default wallclock
preference from EFI_GET_TIME to CMOS RTC, but has grown quite a lot.
First 3 patches should be non-functional changes, mostly chopping the
current logic into smaller functions so that in patch 4 the probing vs
runtime wallclock logic can be split. Patch 5 adds a new command line
option to force the usage of a specific wallclock.

Finally patch 6 changes the preference to use CMOS RTC even when booted
from EFI firmware.

Thanks, Roger.

Roger Pau Monne (6):
  x86/time: introduce helper to fetch Xen wallclock when running as a
    guest
  x86/time: move CMOS edge detection into read helper
  x86/time: split CMOS read and probe logic into function
  x86/time: introduce probing logic for the wallclock
  x86/time: introduce command line option to select wallclock
  x86/time: prefer CMOS over EFI_GET_TIME

 docs/misc/xen-command-line.pandoc |  19 +++
 xen/arch/x86/time.c               | 236 ++++++++++++++++++++++--------
 2 files changed, 198 insertions(+), 57 deletions(-)