Hey Colin, I am curious about this as well. Please provide more information on your setup regarding X2APIC.
On Sat, May 21, 2016 at 10:42 AM, Colin Godsey <crgod...@gmail.com> wrote: > Windows 10 forcing X2APIC: https://support.microsoft.com/en-us/kb/2303458 > > This helped a bunch for me at least on 4.4- I think there was some > confusion on the correct way to signal the guest on what APIC to use, > forcing this gave me much better %sys times. AFAIK it can also still be > used with hyper-v APIC because that’s just the EOI para-virtualization. > > On Fri, May 20, 2016 at 2:28 PM Alex Williamson < > alex.l.william...@gmail.com> wrote: > >> On Fri, May 20, 2016 at 11:38 AM, Nicolas Roy-Renaud < >> nicolas.roy-renau...@ens.etsmtl.ca> wrote: >> >>> Did you have any issues with efifb or some other driver grabbing the >>> gard before vfio-pci? What are your IOMMU groups like, which chard is your >>> boot_vga, what script or method do you use to get vfio-pci to bind with >>> your card, what's your kernel command line and what modules are included in >>> your initramfs? >>> >>> I've struggled with getting my primary GPU to work correctly for a >>> passthrough like this, and I ended up switching it up with the secondary >>> because I simply couldn't get it to work properly (I'd keep getting >>> something about "Invalid ROM contents") and I couldn't see my boot logs >>> until the host driver finished loading. It's really inconvenient now >>> becuase my motherboard is designed so that having a full-size GPU in the >>> second PCIe slot blocks 4 SATA ports out of 6, so I need to have L-shaped >>> cables in a bunch of places to make everything work properly. >>> >> >> The boot VGA ROM is handled differently from other PCI ROMs in Linux, >> when you read it you're actually reading a shadow copy of it placed at >> 0xc0000, which has its roots back in the original IBM PC history. >> Execution of the VGA ROM is allowed to modify this copy of the ROM image in >> memory. Thus you're really not getting a pristine copy of the device ROM >> and it can often lead to these invalid ROM contents messages. I wish we >> provided raw access to the PCI option ROM in these cases as well. For now, >> if you do have these sorts of invalid ROM messages, I would suggest that >> you at least boot with the card as secondary, dump the ROM, then use that >> collected image with the romfile= option rather than use the shadow copy. >> I had to add some code to vfio to fix device IDs and checksums for IGD >> assignment because of this, I don't know if there's any standard fixup we >> can do for other vendors. Thanks, >> >> Alex >> _______________________________________________ >> vfio-users mailing list >> vfio-users@redhat.com >> https://www.redhat.com/mailman/listinfo/vfio-users >> > > _______________________________________________ > vfio-users mailing list > vfio-users@redhat.com > https://www.redhat.com/mailman/listinfo/vfio-users > >
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