[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] Multi-Function PCI passthrough not implemented?
Monday, September 16, 2013, 2:32:52 PM, you wrote: >>>> On 16.09.13 at 14:11, Sander Eikelenboom <linux@xxxxxxxxxxxxxx> wrote: >> Monday, September 16, 2013, 9:27:58 AM, you wrote: >> >>>>>> On 13.09.13 at 23:52, Antonin Bas <antoninb@xxxxxxxxxxxxxxx> wrote: >>>> There are several mentions of these features on the wiki >>>> (http://wiki.xen.org/wiki/VTdHowTo, >>>> http://wiki.xen.org/wiki/Bus:Device.Function_(BDF)_Notation). However, >>>> this is definitely not working and I could not see it implemented >>>> anywhere in libxl. >>>> >>>> I actually even think there is a bug in the code: >>>> >>>> xlu_pci_parse_bdf in libxlu_pci.c accepts inputs of the form >>>> "domain:bus:dev.*" (* is really a star here), which is supposed to >>>> designate all the functions for this PCI device. >>>> In this case, pcidev->func will be set to an uninitiated value by >>>> pcidev_struct_fill(). >>>> Later on, libxl__device_pci_add() and libxl_pcidev_assignable() >>>> (libxl_pci.c) are called with pcidev as an argument. And because >>>> pcidev->func is garbage, an error is thrown. >> >>> You not mentioning the Xen version I'd assume you talk about >>> -unstable, yet looking at the code I can't match things up with >>> what you say above. In fact it looks to me as if multi-function >>> support was properly dealt with by libxl{u,}_pci.c... >> >> Hi Jan, >> >> It is easy to trigger with unstable. >> >> libxl__device_pci_add early on calls libxl_pcidev_assignable to verify the >> device func is assignable, >> but this function isn't multifunction aware and tries to match the >> non-existant function number used >> to to the assignable list which only contains the individual reserved device >> and function numbers. >> >> So it returns false and xl gives an error like: >> libxl: error: libxl_pci.c:1056:libxl__device_pci_add: PCI device 0:7:0.f0 is >> not assignable >> >> >> So libxl_pcidev_assignable should check if it's multifunction is specified, >> and if so check if all 8 func's for this devices >> are assignable. > Ah, okay, I needed to check one call hierarchy level deeper... > Anyway - just wanted to get the situation confirmed, I'll leave > fixing this to our tools experts anyway. CC'ed IanC and Stefano. (resend because i accidentally removed the old CC's) I tried to see how far i could come with outcommenting the safety checks in libxl_pcidev_assignable. It works with qemu-xen-traditional when i specify a vslot for the multifunction pcidev (f.e. pci="00:03:00.*@7"), but i can't see why it is necessary to specify it by hand (unless one would like it to end up at a particular slot for some reason) ? Or is there no other way to "group" the individual functions in the qmp syntax and have them end up on the same vdev ? With qem-xen-(upstream) this fails with a qmp error since it doesn't seem to have no knowledge of the "addr" parameter that gets added by specifying the vslot. -- Sander > Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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