[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] xl.cfg: gfx_passthru documentation improvements
On Mon, Sep 03, 2012 at 11:10:53AM +0100, Ian Campbell wrote: > On Sun, 2012-09-02 at 06:35 +0100, Pasi Kärkkäinen wrote: > > Hello, > > > > xl.cfg.pod.5 documentation improvements: > > > > - gfx_passthru: Document gfx_passthru makes the GPU become primary in the > > guest > > and other generic info about gfx_passthru. > > > > > > Signed-off-by: Pasi Kärkkäinen <pasik@xxxxxx> > > --- docs/man/xl.cfg.pod.5.orig1 2012-09-02 07:16:39.316782158 +0300 > > +++ docs/man/xl.cfg.pod.5 2012-09-02 08:26:40.081639087 +0300 > > @@ -968,7 +968,43 @@ > > > > =item B<gfx_passthru=BOOLEAN> > > > > -Enable graphics device PCI passthrough. XXX which device is passed through > > ? > > +Enable graphics device PCI passthrough. This option makes the passthru > > +graphics card become primary graphics card in the VM, > > The option is slightly misnamed then I guess, a better name would have > been gfx_passthru_primary? oh well, we are stuck with it now. > Yeah.. I think earlier gfx_passthru wasn't a boolean, but an integer, to choose the mode. > (Am I alone in thinking that "thru" is a horrible alternative to > through?) > :) > > so the Qemu emulated > > +graphics adapter is disabled, and the VNC console for the VM won't have > > +any graphics output. All graphics output, including boot time Qemu BIOS > > +messages from the VM, will go to the physical outputs of the passed thru > > +physical graphics card. > > + > > +Graphics card PCI device to passthru is chosen with B<pci> option, > > +exactly in the same way as normal Xen PCI device passthru/assignment is > > done. > > +Note that gfx_passthru doesn't do any kind of sharing > > +of the GPU, so you can only assign the GPU to one single VM at a time. > > + > > +gfx_passthru also enables various legacy VGA memory ranges, BARs, MMIOs, > > +and ioports to be passed thru to the VM, since those are required > > +for correct operation of things like VGA BIOS, text mode, VBE, etc. > > + > > +Enabling gfx_passthru option also copies the physical graphics card > > +video bios to the guest memory, and executes the vbios in the guest > > "BIOS" and (I expect) "VBIOS"? > video bios == vbios, or did you ask something else? > > +to get the graphics card initialized. > > + > > +Most graphics adapters require vendor specific tweaks for properly > > +working graphics passthru. Xen currently includes necessary tweaks > > +for Intel IGD (Integrated Graphics Device) GPUs. > > + > > +Support for AMD/Nvidia gfx_passthru is not yet merged to Xen, > > +but there are out-of-tree patches available. > > If there is a comprehensive list of supported/not-supported devices on > the wiki then I think a reference here would be more useful than these > two brief paragraphs. > We have a list, but it's not up-to-date unfortunately: http://wiki.xen.org/wiki/XenVGAPassthroughTestedAdapters > In particular the second isn't very useful without links and those tend > to become out of date in docs IME, I would tend to omit this from here > and instead include them in the wiki where they can be kept up to date > Ok. I'll fix that, and add a link to: http://wiki.xen.org/wiki/XenVGAPassthrough > (or better yet somebody could finally submit the patches for inclusion). > Indeed. I was talking to both AMD and Nvidia engineers at XenSummit NA 2012, and there's some hope for them to do some work on this stuff :) And I volunteered earlier for this aswell, but so far I've been way too busy with other things :( > > +gfx_passthru is currently only supported with the qemu-xen-traditional > > +device-model. Upstream qemu-xen device-model currently doesn't have > > +support for gfx_passthru. > > + > > +Note that some graphics adapters (AMD/ATI cards, for example) don't > > +necessarily require gfx_passthru option, so you can use the normal > > +Xen PCI passthru to assign the graphics card as a secondary graphics card > > +to the VM. Qemu emulated graphics card stays as the primary graphics card, > > +and you get VNC output from the Qemu-emulated primary adapter. > > + > > > > =item B<nomigrate=BOOLEAN> > > > -- Pasi _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |