Hi,

I got rid of the HVM_FEP condition on the #UD handler.

v1: https://lore.kernel.org/xen-devel/20260122164943.20691-1-alejandro.garciavallejo@amd.com/
pipeline: https://gitlab.com/xen-project/people/agvallejo/xen/-/pipelines/2308391515

Original cover letter:

As discussed in a prior RFC (https://lore.kernel.org/xen-devel/dc68b9ce-38aa-4949-b3e7-a7c0a7ee9a25@citrix.com/)
this series drops cross-vendor support. It includes the policy check that
was there and adds this on top:

  * Eliminates #UD handler when HVM_FEP is disabled.
  * Removes the cross-vendor checks from MSR handlers.
  * Eliminate Intel-behaviour hacks for SYSENTER on AMD handlers and drop
    intercept for SYSENTER.

Open question unrelated to the series: Does it make sense to conditionalise the
MSR handlers for non intercepted MSRs on HVM_FEP?

Cheers,
Alejandro

Alejandro Vallejo (4):
  x86: Reject CPU policies with vendors other than the host's
  x86/hvm: Disable cross-vendor handling in #UD handler
  x86/hvm: Remove cross-vendor checks from MSR handlers.
  x86/svm: Drop emulation of Intel's SYSENTER behaviour on AMD systems

 CHANGELOG.md                             |  5 ++
 xen/arch/x86/hvm/hvm.c                   | 77 +++++++++---------------
 xen/arch/x86/hvm/svm/svm.c               | 45 ++++++--------
 xen/arch/x86/hvm/svm/vmcb.c              |  3 +
 xen/arch/x86/hvm/vmx/vmx.c               |  3 +-
 xen/arch/x86/include/asm/hvm/svm-types.h | 10 ---
 xen/arch/x86/msr.c                       |  8 +--
 xen/lib/x86/policy.c                     |  3 +-
 8 files changed, 64 insertions(+), 90 deletions(-)


base-commit: 3d11d55e19b749697ea7c3799c264b83f5a57a80
-- 
2.43.0