kvm: vmx: handle invvpid vm exit gracefully

kvm: vmx: handle invvpid vm exit gracefully

commit a642fc305053cc1c6e47e4f4df327895747ab485 upstream.

On systems with invvpid instruction support (corresponding bit in
IA32_VMX_EPT_VPID_CAP MSR is set) guest invocation of invvpid
causes vm exit, which is currently not handled and results in
propagation of unknown exit to userspace.

Fix this by installing an invvpid vm exit handler.

This is CVE-2014-3646.

Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2:
 - Adjust filename
 - Drop inapplicable change to exit reason string array]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>