Re: [Xen-devel] pagetable pinning question

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

>  1. Whenever a PD is freed, require the guest to expunge all mappings
>  of the PD from other page directories. Otherwise subsequent attempts
>  to use the PD as a pagetable will fail.

I should clarify that I mean "attempts to use the PD as a _normal_
pagetable will fail". 

Uses as a linear pagetable and uses as a normal pagetable are
different. In the former case we require the mapping to be
read-only. In the latter it is permitted to be read-write. 

So NetBSD would reallocate PD for use as a normal PT and would attempt
to introduce a read-write mapping of the page frame. Unless all linear
mappings of PD have been expunged then this would fail because Xen
thinks that the type is still "page directory". 

 -- Keir


-------------------------------------------------------
The SF.Net email is sponsored by EclipseCon 2004
Premiere Conference on Open Tools Development and Integration
See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
http://www.eclipsecon.org/osdn
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel