[PATCH v2 0/3] xen/pv: sanitize xen pv guest msr accesses

From: Juergen Gross
Date: Tue Oct 04 2022 - 04:44:25 EST

Historically when running as Xen PV guest all MSR accesses have been
silently swallowing any GP faults, even when the kernel was using not
the *msr_safe() access functions.

Change that by making the behavior controllable via kernel config and
via a boot parameter.

This will help finding paths where MSRs are being accessed under Xen
which are not emulated by the hypervisor.

Juergen Gross (3):
xen/pv: allow pmu msr accesses to cause GP
xen/pv: refactor msr access functions to support safe and unsafe
xen/pv: support selecting safe/unsafe msr accesses

.../admin-guide/kernel-parameters.txt | 6 ++
arch/x86/xen/Kconfig | 9 ++
arch/x86/xen/enlighten_pv.c | 99 +++++++++++++------
arch/x86/xen/pmu.c | 61 ++++++------
4 files changed, 118 insertions(+), 57 deletions(-)