Re: [Qemu-devel] commit : "virtio: set ISR on dataplane notifications" breaks virtio-pci network on linux guest.

[Brad Campbell]

On 18/01/17 10:21, Brad Campbell wrote:
> G'day all,
>
> Upgrading from 2.7.1 to 2.8 on my machines here leaves the guests
> without networking. All guests are using a vanilla self-compiled 4.8.12
> kernel. The host is using a 4.9.3 kernel.
>
> Guests are using virtio networking into a bridge on the host.

Further testing indicates this only breaks when CONFIG_GENERIC_MSI_IRQ 
is not set in the guest kernel. My guest kernel didn't have this 
enabled. Once I recompiled and re-deployed the kernels, all linux VM's 
networked fine.

I can however confirm it breaks Windows XP 32 bit guests. Upgrading to 
the latest driver (51.74.104.13000) does not solve the problem either, 
so I've had to go back to 2.7.1 to be able to use these Windows VM's.

When I get some time I'll try and set up a test environment outside of 
libvirt and run further tests.

Regards,
Brad