>>> On 13.09.18 at 08:41, <kevin.t...@intel.com> wrote: >> From: Paul Durrant >> Sent: Wednesday, September 12, 2018 4:02 PM >> >> > I also have another more general concern: Allowing the guest to >> > manipulate its IOMMU page tables means that it can deliberately >> > shatter large pages, growing the overall memory footprint of the >> > domain. I'm hesitant to say this, but I'm afraid that resource >> > tracking of such "behind the scenes" allocations might be a >> > necessary prereq for the PV IOMMU work. >> > >> >> Remember that PV-IOMMU is only available for dom0 as it stands (and that >> is the only use-case that XenServer currently has) so I think that, whilst >> the >> concern is valid, there is no need danger in putting the code without such >> tracking. Such work can be deferred to making PV-IOMMU for de-privileged >> guests... if that facility is needed. > > I didn't get why this is PV-IOMMU specific. Guest can always manipulate > guest CPU page table to shatter large pages too...
Hmm, good point. I keep forgetting that we allow guests to fiddle with their own p2m. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
