On Fri, Nov 28, 2014 at 08:00:40PM -0600, Dr. Greg Wettstein wrote: > On Nov 27, 12:11pm, Sander Eikelenboom wrote: > } Subject: Re: [Xen-devel] Q77 IGD instantly crashes on xen-pciback bind. > > Hi, hope the week has gone well for everyone. > > > > So we are obviously working with qemu-dm-traditional and with the > > > IGD/LVDS BIOS configuration issue fixed the adapater passthrough is > > > working and Windows7 is coming up and detecting the IGD as a standard > > > VGA display adapter. Additional invocations of the VM after the first > > > one result in failed passthrough with a garbled display. > > > This is probably due to the current lack of slot/bus reset in > > xen-pciback, Konrad has a preliminary kernel patch for xen-pciback > > that does this. I have attached the patch, though it has some rough > > edges in the design :-) > > > > I'm currently running with his 3.19 xen-pciback patches series + the > > preliminary patch for slot/bus reset and rebooting a guest with > > vga/pci passthrough now works. (i'm running with a radeon card, > > passed through as a secondary card to the emulated qemu one, in a > > linux guest using qemu-xen, so i can't help you with your other > > questions and problems). > > Thanks for taking the time for respond and forward along the patch. > > I back ported the do_flr patch into the 3.14.x kernel and spent some > time working with it. I thought it might be useful to others to > document what we ran into. > > First of all the issue with the unsuccessful boot of Windows after the > first invocation doesn't appear to have anything to do with resetting > the card. This was fixed by installing the most recent version of the > Intel HD drivers in the Windows guest. > > If IGD passthrough is done without the HD drivers Windows 7 appears to > use its standard VGA driver which seems to be able to initialize and > run the IGD device but does not appear to shutdown the device in a > manner in which it can be re-started. After the first invocation of > the guest is shutdown the screen goes to a solid color. Subsequent > invocations result in the flashing multi-color screens which others > have documented. > > With the HD drivers installed IGD passthrough works fine through > multiple invocations of a guest with the stock xen-pciback in 3.14.x. > We ran 40-50 repetitive Windows guest invocations and every one was > completely deterministic. > > That being said we ran into an issue which we wanted to bounce off the > list in the context of this thread. > > One of the things we were not able to do was to successfuly re-start > the IGD display for dom0. After spending a lot of time going through > Konrad's reset code it appears the IGD devices in the Q77 and Q87 > chipset implementations we are looking at are not advertising reset > functions which can be used. > > It appears that the IGD devices are advertising that they need a > Device Specific Initialization (DSI) sequence in order to be enabled > or powered up, if we interpret the output of lscpi properly, ie: > > --------------------------------------------------------------------------- > 00:02.0 VGA compatible controller: Intel Corporation Device 0152 (rev 09) > (prog-if 00 [VGA controller]) > Subsystem: Intel Corporation Device 2036 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR- FastB2B- DisINTx- > Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- > <TAbort- > <MAbort- >SERR- <PERR- INTx- > Latency: 0 > Interrupt: pin A routed to IRQ 11 > Region 0: Memory at f7800000 (64-bit, non-prefetchable) [size=4M] > Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M] > Region 4: I/O ports at f000 [size=64] > Expansion ROM at <unassigned> [disabled] > Capabilities: [90] MSI: Mask- 64bit- Count=1/1 Enable- > Address: 00000000 Data: 0000 > Capabilities: [d0] Power Management version 2 > Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA > PME(D0-,D1-,D2-,D3hot-,D3cold-) > Status: D0 PME-Enable- DSel=0 DScale=0 PME- > Capabilities: [a4] PCIe advanced features <?> > --------------------------------------------------------------------------- > > The ATI adapters which we have a lot of passthrough experience with > are FLR capable and can be re-enabled after passthrough by writing a > '1' to the enable pseudo-file in the /sys/bus/pci/devices/BDF > directory. The IGD adapters seem to fail to respond to a request to > be re-enabled. > > We would certainly be interested in any suggestions the collective may > have with respect to how to get the adapter turned back on and/or > implement a reset.
CC-ing Chien who has been looking at adding IGD passthrough support in the qemu-upstream. Perhaps he can provide some ideas. Thanks. > > > Sander > > Have a good weekend. > > Greg > > }-- End of excerpt from Sander Eikelenboom > > As always, > Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC. > 4206 N. 19th Ave. Specializing in information infra-structure > Fargo, ND 58102 development. > PH: 701-281-1686 > FAX: 701-281-3949 EMAIL: g...@enjellic.com > ------------------------------------------------------------------------------ > "Laugh now but you won't be laughing when we find you laying on the > side of the road dead." > -- Betty Wettstein > At the Lake _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
