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xen-devel
Re: [Xen-devel] Regarding page table management changes from Xen v1 to X
> >Could you tell me another example other than fork when one can use
> >batched PTE
> >modifications.
>
> fork() is the only one for us these days. All others use
> update_va_mapping(), act on pagetables that aren't pinned (so the guest
> can directly update them without faulting) or are infrequent enough we
> do not care.
Not sure I understand the last part (aren't pinned ...) - my assumptions about
page tables are (these apply to both direct mapped and shadow page tables):
1. Always pinned (backed) - so a access to them cannot cause a page unavailable
fault.
2. Always read only to guest - so a read access to them is fine, but a write
access
will cause a protection fault.
Both of these faults are reflected as a PG fault.
Are you refering to the case when Xen has "detached" the page table page and
has made it RW for guest?
Thanks for your answers and patience :-).
-Himanshu
--
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Himanshu Raj
PhD Student, GaTech (www.cc.gatech.edu/~rhim)
I prefer to receive attachments in an open, non-proprietary format.
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