On 04/09/14 15:31, Jan Beulich wrote:
No, there no such dependency - the kernel could use 4 levels atOn 04/09/14 13:59, David Vrabel wrote:On 04.09.14 at 15:02, <andrew.cooper3@xxxxxxxxxx> wrote:
On 04/09/14 13:38, Juergen Gross wrote:Any increase of the p2m beyond 3 levels will need to come with
Direct Xen to place the initial P->M table outside of the initialThe three level p2m limits memory to 512 GiB on x86-64 but this patch
mapping, as otherwise the 1G (implementation) / 2G (theoretical)
restriction on the size of the initial mapping limits the amount
of memory a domain can be handed initially.
doesn't seem to address this limit and thus seems a bit useless to me.
substantial libxc changes first. 3 level p2ms are hard coded throughout
all the PV build and migrate code.
any time (sacrificing being able to get migrated), making sure it
only exposes the 3 levels hanging off the fourth level (or not
exposing this information at all) to external entities making this
wrong assumption.
Jan
That would require that the PV kernel must start with a 3 level p2m and
fudge things afterwards.
At a minimum, I would expect a patch to libxc to detect a 4 level PV
guest and fail with a meaningful error, rather than an obscure "m2p
doesn't match p2m for mfn/pfn X".