Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.
Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>