tree bdf4b3bdb4fdcd5672990e51a211b8dc15e04ae1
parent 66c78ae40cd0a7258d01ef433ede74e33e4adbbe
author Nadav Har'El <nyh@il.ibm.com> 1306354478 +0300
committer Avi Kivity <avi@redhat.com> 1310460318 +0300

KVM: nVMX: Handling of CR0 and CR4 modifying instructions

When L2 tries to modify CR0 or CR4 (with mov or clts), and modifies a bit
which L1 asked to shadow (via CR[04]_GUEST_HOST_MASK), we already do the right
thing: we let L1 handle the trap (see nested_vmx_exit_handled_cr() in a
previous patch).
When L2 modifies bits that L1 doesn't care about, we let it think (via
CR[04]_READ_SHADOW) that it did these modifications, while only changing
(in GUEST_CR[04]) the bits that L0 doesn't shadow.

This is needed for corect handling of CR0.TS for lazy FPU loading: L0 may
want to leave TS on, while pretending to allow the guest to change it.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>