On guest writing a PPGTT entry, if it contains value and the old
entry is valid, gvt will read it and find & free the corresponding
old data for it. However, with the KVM write protection provided
by page_track, the guest entry will be written with new value
before gvt handling. To avoid that, we should use the shadow
entry instead.
Signed-off-by: NBing Niu <bing.niu@intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>