[Bug 236922] Virtio fails as QEMU-KVM guest with Q35 chipset on Ubuntu 18.04.2 LTS

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236922

--- Comment #20 from John Hartley <drum at graphica.com.au> ---
Hi Tommy P,

thanks very much for response.

Yes I am using GENERIC kernel, I did try a custom kernel removing all the
unused devices but that also failed.

Yes agree that issue relates to Q35.

Since original posting I have done testing with Q35 with BIOS & OVMF Firmware
and find that with 11.3 and 12.x that VirtIO based device all fail.

Unfortunately with 11.3 & 12.x all available NIC device options (not just
VirtIO) also fail (e1000, e1000-82545em, rtl8130 & vmxnet3).

So issue extends beyond just VirtIO based devices.

It seems that between 11.2 and 11.3 there where some changes make to PCI
sub-system the result of which is that the PCIe (??) enumeration if failing to
detect that NICs at all.

Yesterday I tried to build a 11.3 kernel with 11.2 dev/pci code, but ended up
pulling in more code than I wanted, so likely pulled in the associated buggy
commits to get kernel complied.

Your tip on swapping to i440FX is worth looking at I assumed that as I have
built OVMF VMs that thee would only work with Q35 as OVMF option is tied to
this.

I will do more building and testing later today.

For my next build I will only keep dev/pci/pcireg.h file from 11.3 and wind
back to 11.2 any (non PCI code)flow through changes that this breaks as part of
this test.

I am focused on pci code as Q35 is PCIe native VM and the dev/pci source tree
has a hold host of commit/reverts so hoping to at least be able to further
isolate problem here.

If I can get generic NICs enumerating then could fold in fix you have
identified with VirtIO code and PCI identifiers...


Thanks very much for feedback.

Cheers,

John Hartley.

-- 
You are receiving this mail because:
You are the assignee for the bug.