[v2,0/2] nvmx: implement support for MSR bitmaps

Message

Roger Pau Monné Jan. 29, 2020, 2:45 p.m. UTC

Hello,

Current nested VMX code advertises support for the MSR bitmap feature,
yet the implementation isn't done. Previous to this series Xen just maps
the nested guest MSR bitmap (as set by L1) and that's it, the L2 guest
ends up using the L1 MSR bitmap.

This series adds handling of the L2 MSR bitmap and merging with the L1
MSR bitmap and loading it into the nested guest VMCS.

Patch #2 makes sure the x2APIC MSR range is always trapped, or else a
guest with nested virtualization enabled could manage to access some of
the x2APIC MSR registers from the host.

Thanks, Roger.

Roger Pau Monne (2):
  nvmx: implement support for MSR bitmaps
  nvmx: always trap accesses to x2APIC MSRs

 xen/arch/x86/hvm/vmx/vvmx.c        | 73 ++++++++++++++++++++++++++++--
 xen/include/asm-x86/hvm/vmx/vvmx.h |  3 +-
 2 files changed, 72 insertions(+), 4 deletions(-)