[Xen-devel] Re: [RFC PATCH v01] Xen PVSCSI drivers for pvops xen/stable-2.6.32.x kernel

[Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>]

On Fri, 2011-01-07 at 10:03 +0000, Nathanael Rensen wrote:
> On 7 January 2011 06:35,  Pasi KÃrkkÃinen <pasik@xxxxxx> wrote:
> > Hello,
> >
> > http://pasik.reaktio.net/xen/patches/xen-pvscsi-drivers-linux-2.6.32.27-pvops-v01.diff
> >
> > This is the first version of Xen PVSCSI drivers, both the scsiback backend 
> > and
> > scsifront frontend, ported from Novell SLES11SP1 2.6.32 Xenlinux kernel to
> > pvops xen/stable-2.6.32.x branch.
> >
> > -- Pasi
> 
> That's great. Some comments based on my experience with pvusb:
> 
> 1) You've added GNTST_eagain into include/xen/interface/grant_table.h.
> When porting the pvusb drivers I removed the "check and retry" loops
> based on GNTST_eagain because I noticed that netback and blkback don't
> do that. Looking at the grant_table code in xen-4.0-testing I don't
> think GNTST_eagain is used now. Perhaps someone with knowledge of the
> history of GNTST_eagain could help to clarify.

IIRC GNTST_eagain was added to the classic Xen trees but never forward
ported to pvops.

It's part of the page sharing paging work (so dom0 can deal with a
paged/shared guest rather than for paging of dom0 itself). I guess those
don't work with pvops kernels? CC'ing the guys who are working on that
stuff.

(The presence of the use of msleep in the eagain case is a bit
terrifying. Stripping it out for now and redoing it might not be a bad
plan)

Ian.


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