[PATCH v2 0/2] Add API for making parts of a MMIO page R/O and use it in XHCI console

[Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>]

On older systems, XHCI xcap had a layout that no other (interesting) registers
were placed on the same page as the debug capability, so Linux was fine with
making the whole page R/O. But at least on Tiger Lake and Alder Lake, Linux
needs to write to some other registers on the same page too.

Add a generic API for making just parts of an MMIO page R/O and use it to fix
USB3 console with share=yes or share=hwdom options. More details in commit
messages.

Marek Marczykowski-Górecki (2):
  x86/mm: add API for marking only part of a MMIO page read only
  drivers/char: Use sub-page ro API to make just xhci dbc cap RO

 xen/arch/x86/hvm/emulate.c      |   2 +-
 xen/arch/x86/hvm/hvm.c          |   8 +-
 xen/arch/x86/include/asm/mm.h   |  15 ++-
 xen/arch/x86/mm.c               | 253 +++++++++++++++++++++++++++++++++-
 xen/arch/x86/pv/ro-page-fault.c |   1 +-
 xen/drivers/char/xhci-dbc.c     |  14 +--
 6 files changed, 284 insertions(+), 9 deletions(-)

base-commit: 99a9c3d7141063ae3f357892c6181cfa3be8a280
-- 
git-series 0.9.1