[0/8] x86: switch default MSR behavior

Message

Roger Pau Monne Aug. 17, 2020, 3:57 p.m. UTC

Hello,

The current series attempts to change the current MSR default handling
behavior, which is to silently drop writes to writable MSRs, and allow
reading any MSR not explicitly handled.

After this series access to MSRs not explicitly handled will trigger a
#GP fault. I've tested this series with osstest and it doesn't introduce
any regression, at least on the boxes selected for testing:

http://logs.test-lab.xenproject.org/osstest/logs/152602/

Thanks, Roger.

Andrew Cooper (1):
  x86/hvm: Disallow access to unknown MSRs

Roger Pau Monne (7):
  x86/vmx: handle writes to MISC_ENABLE MSR
  x86/svm: silently drop writes to SYSCFG and related MSRs
  x86/pv: handle writes to the EFER MSR
  x86/pv: handle reads to the PAT MSR
  x86/pv: allow reading APIC_BASE MSR
  x86/pv: allow reading FEATURE_CONTROL MSR
  x86/pv: disallow access to unknown MSRs

 xen/arch/x86/hvm/svm/svm.c     | 21 +++++++++--
 xen/arch/x86/hvm/vmx/vmx.c     | 20 ++++++----
 xen/arch/x86/pv/emul-priv-op.c | 68 +++++++++++++++++++++++++---------
 3 files changed, 79 insertions(+), 30 deletions(-)