Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:[EOL][EOL]iommu/vt-d: Disallow dirty tracking if incoherent page walk[EOL][EOL]Dirty page tracking relies on the IOMMU atomically updating the dirty bit[EOL]in the paging-structure entry. For this operation to succeed, the paging-[EOL]structure memory must be coherent between the IOMMU and the CPU. In[EOL]another word, if the iommu page walk is incoherent, dirty page tracking[EOL]doesn't work.[EOL][EOL]The Intel VT-d specification, Section 3.10 "Snoop Behavior" states:[EOL][EOL]"Remapping hardware encountering the need to atomically update A/EA/D bits[EOL] in a paging-structure entry that is not snooped will result in a non-[EOL] recoverable fault."[EOL][EOL]To prevent an IOMMU from being incorrectly configured for dirty page[EOL]tracking when it is operating in an incoherent mode, mark SSADS as[EOL]supported only when both ecap_slads and ecap_smpwc are supported.