Hi All,

I'm planning to send v3 - so would be appreciated for any other comments.

On 19.11.25 21:30, Grygorii Strashko wrote:
From: Grygorii Strashko <[email protected]>

Hi

This series introduces possibility to disable 32-bit (COMPAT) interface support
in the following case:
       - Only PVH domains are used
       - Guests (OS) are started by using direct Direct Kernel Boot
       - Guests (OS) are 64-bit and Guest early boot code, which is running not
         in 64-bit mode, does not access Xen interfaces
         (hypercalls, shared_info, ..)

If above criterias are met the COMPAT HVM interface become unreachable and can 
be disabled.
Coverage reports analyze and adding guard (debug) exceptions in 
hvm_hypercall/hvm_do_multicall_call
and hvm_latch_shinfo_size() confirm that COMPAT HVM interface is unused for 
safety use-case.

Changes in v2 described in each patch:
- patch "x86: constify has_32bit_shinfo() if !CONFIG_COMPAT" squashed in patch 
2.

v1:
  
https://patchwork.kernel.org/project/xen-devel/cover/[email protected]/

Grygorii Strashko (4):
   x86: hvm: dm: factor out compat code under ifdefs
   x86: hvm: compat: introduce is_hcall_compat() helper
   x86: hvm: factor out COMPAT code under ifdefs
   x86: pvh: allow to disable 32-bit interface support

  xen/arch/x86/hvm/Kconfig          | 19 ++++++++++++++++++-
  xen/arch/x86/hvm/dm.c             |  2 ++
  xen/arch/x86/hvm/hvm.c            | 24 ++++++++++++++++++++----
  xen/arch/x86/hvm/hypercall.c      | 22 +++++++++++++++++-----
  xen/arch/x86/hypercall.c          |  6 +-----
  xen/arch/x86/include/asm/domain.h |  9 +++++++--
  xen/common/kernel.c               |  2 +-
  xen/include/hypercall-defs.c      |  9 +++++++--
  xen/include/xen/sched.h           |  9 +++++++++
  9 files changed, 82 insertions(+), 20 deletions(-)


--
Best regards,
-grygorii


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