[vfio-users] How to choose a compatible motherboard?

[Blank Field]

vga=none will effectively disable most filthy VGAcon stuff, vesafb the same
as he said.

Also, setting up a headless system should be extra easy on an UEFI host...
On Oct 22, 2015 11:33 PM, "Alex Williamson" <alex.l.williamson at gmail.com>
wrote:

> On Thu, Oct 22, 2015 at 2:14 PM, Nick Sukharev <nicksukharev at gmail.com>
> wrote:
>
>> I had this issue with my 1st PCIE slot. Three steps helped:
>> 1) disabling radeon driver by
>> creating /etc/modprobe.d/blacklistradeon.conf with a single line
>> blacklist radeon
>> 2) specifying GRUB_CMDLINE_LINUX="nomodeset vga=normal video=vesafb:off"
>> in /etc/default/grub
>> 3) Using "pure" OVMF.
>>
>
> Don't you still get a VGA mode login prompt on the primary graphics on the
> host?  That means the host is writing into the VGA space of the device,
> even while the device is in use by the guest.  Maybe it doesn't cause any
> noticeable problem since you're using OVMF, but it's still concerning.
> I've tried this in the past and bumped a keyboard connected to the host
> while the guest (Linux) was in text mode and got a host login prompt on the
> guest-owned graphics... very confusing.  I think there's a step missing
> here about detaching the VGA device from vgacon.
>
>
>> I am pretty sure steps 1 and 3 are also required for secondary slots on
>> my MB unless I want to use just one non-gpu slot for gpu, then it works
>> with seabios.
>> I still get this in dmesg:
>> vfio-pci 0000:03:00.0: Invalid ROM contents
>> but no issues because of that.
>>
>
> Linux has special handling for the boot VGA ROM, it's read from the shadow
> ROM at 0xc0000, which isn't ROM at all and often gets modified by the ROM
> execution at boot time.  Primary graphics, even if not used for a console,
> is therefore always more likely to need the ROM passed as a file.
>
>
>> I was trying to make all PCIE slots available for passthrough, if that is
>> not required some old NVidia in the 1st slot and a radeon in the 2nd (or
>> vice versa) should be easier. With 1,2,3 I can go completely "headless" in
>> the sense that I am using USB graphhics on that machine for host.
>> Also, Haswell i7-5820K works perfectly for x99 socket 2011-3, no need to
>> go for a Xenon. I doubt you can get 6 core Xenon for a comparable price.
>>
>
> "perfectly" minus not supporting ACS on the processor root ports.  There
> is still a reason to go for a Xeon.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20151022/46afba6b/attachment.htm>