EPT tables are shared by MMU and IOMMU.
Some IOMMUs don't support page-walk coherency, the cpu cache of EPT entires
should be flushed to memory after modifications, so that the modifications
are visible to the IOMMUs.
This patch adds a new interface to flush the cache of modified EPT entires.
There are different implementations for EPT/PPT entries:
- For PPT, there is no need to flush the cpu cache after update.
- For EPT, need to call iommu_flush_cache to make the modifications visible
to IOMMUs.
Tracked-On: #3607
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
5c81659713