Re: [Xen-devel] Xen's Linux kernel config options

[Juergen Gross <jgross@xxxxxxxx>]

On 12/12/2014 06:29 PM, David Vrabel wrote:
> On 12/12/14 13:17, Juergen Gross wrote:
> > As a first draft I'd suggest the following:
> Some rough thoughts below.
>
> > Option                          Selects                 Depends
> > ----------------------------------------------------------------------
> > XEN                             SWIOTLB_XEN(arm,arm64)
> XEN should get you basic support for making hypercalls and allowing
> guest to identify themselves as running on Xen.  I don't think it should
> select SWIOTLB_XEN even on ARM as it is only needed for guests with
> access to real hardware.
Okay.

> >    XEN_PV(x86)                   XEN_HAVE_PVMMU
> >                                  PARAVIRT
> >                                  PARAVIRT_CLOCK
> >    XEN_PVH(x86)                  XEN_PVHVM
> >                                  PARAVIRT
> >                                  PARAVIRT_CLOCK
> >    XEN_BACKEND                                           XEN_PV(x86) ||
> >                                                          XEN_PVH(x86) ||
> >                                                          XEN_PVHVM
> >      XEN_BLKDEV_BACKEND
> >      XEN_PCIDEV_BACKEND(x86)
> >      XEN_SCSI_BACKEND
> >      XEN_NETDEV_BACKEND
> [...]
> > XEN_PVHVM
> Move XEN_PVHVM under XEN and have it select PARAVIRT and PARAVIRT_CLOCK.
Okay.

> > XEN_FRONTEND                                            XEN_PV ||
> >                                                          XEN_PVH ||
> >                                                          XEN_PVHVM
> This enables all the basic infrastructure for frontends: event channels,
> grant tables and Xenbus.
>
> Don't make XEN_FRONTEND depend on any XEN_* variant.  It should be
> possible to have frontend drivers without support for any of the
> PV/PVHVM/PVH guest types.  Frontends only need event channels, grant
> table and xenbus.
Okay.

> Perhaps have XEN_FRONTEND select XEN instead?
Hmm, with XEN not selecting anything else automatically (apart from
stuff needed by frontends AND backends) this would be okay, I think.

> You need an additional option to enable the Xen platform PCI device.
> This should depend on XEN_FRONTEND.
Yep.

> >    XEN_XENBUS_FRONTEND
> Fold this into XEN_FRONTEND?
Hmm, what about Xenstore in an own domain? I'd say XEN_FRONTEND should
select XEN_XENBUS_FRONTEND, but XEN_XENBUS_FRONTEND should be available
to non-frontend domains as well.

> >    XEN_FBDEV_FRONTEND            XEN_XENBUS_FRONTEND
> >                                  INPUT_XEN_KBDDEV_FRONTEND
> >    XEN_BLKDEV_FRONTEND           XEN_XENBUS_FRONTEND
> >    HVC_XEN_FRONTEND              XEN_XENBUS_FRONTEND
> >                                  HVC_XEN
> >    TCG_XEN                       XEN_XENBUS_FRONTEND
> >    XEN_PCIDEV_FRONTEND           PCI_XEN
> >                                  XEN_XENBUS_FRONTEND
> >    XEN_SCSI_FRONTEND             XEN_XENBUS_FRONTEND
> >    INPUT_XEN_KBDDEV_FRONTEND     XEN_XENBUS_FRONTEND
> >    XEN_NETDEV_FRONTEND           XEN_XENBUS_FRONTEND
> >
> > There might be some further adjustments needed (should XEN_DEV_EVTCHN
> > and XEN_GNTDEV belong to XEN_BACKEND?), but these are minor nits. The
> > main difference to the current status is the XEN setting no longer
> > controlling all other options.
> XEN_DEV_EVTCH and XEN_GNTDEV are useful to non-backends (e.g., for
> interdomain comms).
Okay.


Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel