Re: [Xen-devel] [PATCH v2] IOMMU: make DMA containment of quarantined devices optional

[Jan Beulich <jbeulich@xxxxxxxx>]

On 13.12.2019 14:53, Durrant, Paul wrote:
> Since *not* having the 'sink' page allows a guest pull off a host DoS
> in the presence of such h/w, security is surely increased by having it?

host            device          result w/o sink         result w/ sink
good            good            good                    good
good            babbling        good                    good
wedge on fault  good            DoS (runtime)           DoS (runtime)
wedge on fault  babbling        DoS (runtime/late)      DoS (runtime only, 
silent)

I wouldn't call it an increase of security to fully hide post-
deassignment issues without doing anything about issues that can
arise while the device is still assigned.

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel