Re: [Xen-devel] GNTTAB_copy

[Steven Smith <steven.smith@xxxxxxxxxx>]

> 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.

Attachment: signature.asc
Description: Digital signature

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel