> Please find the patches attached with this email.
>
> The changes you are interested are in grant_table.patch
Ah, okay. It looks from the patch as if you're using the grant copy
hypercall to do direct MFN-to-MFN copies across a domain boundary,
without any actual grant references getting in the way. Is that
correct? If so, you may want to re-think your design; grant
references are Xen's principle access control mechanism for memory,
and if you're not using them then it's likely to be difficult to make
your design suitably secure.
(Of course, if this is just a research prototype, you may decide you
don't care about such things, in which case best of luck to you.)
Steven.
> -----Original Message-----
> From: Steven Smith [mailto:steven.smith@xxxxxxxxxx]
> Sent: Thursday, February 05, 2009 4:13 PM
> To: Kumar, Venkat
> Cc: Steven Smith; xen-devel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-devel] GNTTAB_copy
>
>
>
> > Atlast it worked out. I had to make some changes in Xen (it wasn't
>
> > allowing a copy across domains) to make it work apart from the patch
>
> > you sent.
>
> That's odd. Would you mind sending me your patch, please, so that I
>
> can see what's wrong with the existing implementation?
>
>
>
> Steven.
>
>
>
>
>
> > -----Original Message-----
>
> > From: Steven Smith [mailto:steven.smith@xxxxxxxxxx]
>
> > Sent: Friday, January 30, 2009 10:04 PM
>
> > To: Kumar, Venkat
>
> > Cc: Steven Smith; xen-devel@xxxxxxxxxxxxxxxxxxx
>
> > Subject: Re: [Xen-devel] GNTTAB_copy
>
> >
>
> > > Steve,
>
> > >
>
> > > I have ported the GNTTAB_copy part from netchannel2 xen-unstable to
> > > xen-unstable. But the hypercall is failing with a status -1.
>
> > >
>
> > > xm dmesg says
>
> > > ===========================================
>
> > > Bad flags (0) or dom (0). (expected dom 9)
>
> > > ===========================================
>
> > Okay, so Xen started processing the grant table operation, but found
>
> > that the grant entry in the granting domain's grant table was bad
>
> > (because it was full of zeroes). That probably indicates that it was
>
> > accessing completely the wrong gref.
>
> >
>
> > > I am granting the page with a flag ( GTF_reading | GTF_writing &
> > > GTF_permit_access ) but still it did not work.
>
> > >
>
> > > What could be wrong here?
>
> > I'm not sure. I'd suggest you put some printks in your guests (both
>
> > the granting one and the HVM one) to make sure that they agree on the
>
> > grant reference number, and some in Xen to make sure that it's reading
>
> > the hypercall arguments correctly.
>
> >
>
> > Steven.
>
> >
>
> >
>
> > > -----Original Message-----
>
> > > From: Steven Smith [mailto:steven.smith@xxxxxxxxxx]
>
> > > Sent: Friday, January 30, 2009 4:52 PM
>
> > > To: Kumar, Venkat
>
> > > Cc: Steven Smith; xen-devel@xxxxxxxxxxxxxxxxxxx
>
> > > Subject: Re: [Xen-devel] GNTTAB_copy
>
> > >
>
> > > That's unfortunate; the repository works fine for me.
>
> > >
>
> > > There aren't any other ways of downloading the entire repository, but
>
> > > the changes you need to make are pretty self-contained, so I've
>
> > > attached the relevant cset. You'll need to get rid of the
>
> > > GNTTABOP_set_version bits, but apart from that it should all be fairly
>
> > > obvious.
>
> > >
>
> > > Steven.
>
> > >
>
> > >
>
> > > > Steven - Thanks for the pointer.
>
> > > > I get an error while downloading the code.
>
> > > >
>
> > > > =======================================================================
>
> > > > hg clone http://xenbits.xensource.com/ext/netchannel2/xen-unstable.hg
>
> > > > destination directory: xen-unstable.hg
>
> > > > requesting all changes
>
> > > > adding changesets
>
> > > > transaction abort!
>
> > > > rollback completed
>
> > > > abort: Connection reset by peer
>
> > > > =======================================================================
>
> > > >
>
> > > > Do you know any alternate download?
>
> > > >
>
> > > > Venkat
>
> > > >
>
> > > > -----Original Message-----
>
> > > > From: Steven Smith [mailto:steven.smith@xxxxxxxxxx]
>
> > > > Sent: Friday, January 30, 2009 4:18 PM
>
> > > > To: Kumar, Venkat
>
> > > > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
>
> > > > Subject: Re: [Xen-devel] GNTTAB_copy
>
> > > >
>
> > > > > Is GNTTAB_copy command in the Hypercall "HYPERVISOR_grant_table_op"
>
> > > > > supported between two HVM's?
>
> > > > It's not in xen-unstable, no, but it is if you use the netchannel2
>
> > > > hypervisor (available from
>
> > > > http://xenbits.xensource.com/ext/netchannel2/xen-unstable.hg). It'd
>
> > > > be pretty easy to cross-port, if you wanted to have a go at that. The
>
> > > > interesting cset is this one:
>
> > > >
>
> > > > changeset: 19112:ea4b9c439ac3
>
> > > > user: Steven Smith <steven.smith@xxxxxxxxxxxxx>
>
> > > > date: Thu Jan 22 09:53:12 2009 +0000
>
> > > > files: xen/arch/x86/hvm/hvm.c xen/include/xen/hypercall.h
>
> > > > description:
>
> > > > Allow GNTABOP_copy to be used from HVM domains.
>
> > > >
>
> > > > Steven.
signature.asc
Description: Digital signature
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home