> -----Original Message----- > From: Fabio Fantoni [mailto:fabio.fant...@m2r.biz] > Sent: Monday, May 19, 2014 3:48 PM > To: Gerd Hoffmann; Chen, Tiejun > Cc: peter.mayd...@linaro.org; xen-de...@lists.xensource.com; > m...@redhat.com; Kay, Allen M; stefano.stabell...@eu.citrix.com; > weidong....@intel.com; kelly.zyta...@amd.com; > jean.guya...@eu.citrix.com; qemu-devel@nongnu.org; Zhang, Yang Z; > anth...@codemonkey.ws; anthony.per...@citrix.com > Subject: Re: [Xen-devel] [Qemu-devel] [v2][PATCH 4/8] xen, gfx passthrough: > reserve 00:02.0 for INTEL IGD > > Il 19/05/2014 08:44, Gerd Hoffmann ha scritto: > > Hi, > > > >> + /* > >> + * Some video bioses and gfx drivers will assume the bdf of IGD is > 00:02.0. > >> + * So user need to set it to 00:02.0 in Xen configure file explicitly, > >> + * otherwise IGD will fail to work. > >> + */ > >> + pci_reserve_pci_devfn(b, PCI_DEVFN(2, 0)); > > That is asking for trouble. Slot 2 is used by the qemu vga cards by > > default, and for quite a while (before memory api was merged) it even > > was impossible to change it. libvirt still places the vga card at > > slot > > 2 for that reason -> boom. I wouldn't be surprised if you find that > > assumption in other management libs / apps too. > > > > Why do you need that patch in the first place? It should be possible > > to configure qemu to not occupy slot 2 if you need it that way. Just > > pass '-vga none' to qemu. Which you probably want anyway if you > > pass-through a vga to the guest. And explicitly configure a slot (via > > addr= > > property) for all your pci devices. Doing it only for the IGD works > > too if you list the device before any other pci device on the qemu > > command line. > > > > cheers, > > Gerd > > I already added vga none support on libxl, useful also for this cases: > http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=2e5738ff47b9d2e19480 > 24100f87b1a25fcf004a > > This patch is already tested and working, for now I not tested and I can't > test > with intel gpu passthrough, someone can test it with intel gpu passthrough? > > Thanks for any reply and sorry for my bad english.
But I think what we intend is to reserve a specific slot to work vga passthrough on IGD. Thanks Tiejun
