[Xen-devel] [RFC 21/23] net/xen-netback: Make it running on 64KB page granularity

On 19/05/15 23:56, Julien Grall wrote:

quoted

If you're wgetting from another host, I would suggest wgetting from Dom0
to limit the problem between Dom0 and DomU.

Thanks to Wei, I was able to narrow the problem. It looks like the
problem is not coming from netback but somewhere else down in the
network stack: wget/ssh between Dom0 64KB and DomU is working fine.

Although, wget/ssh between a guest and an external host doesn't work
when Dom0 is using 64KB page granularity unless if I start a tcpdump on
the vif in DOM0. Anyone an idea?

I have no issue to wget/ssh in DOM0 to an external host and the same
kernel with 4KB page granularity (i.e same source code but rebuilt with
4KB) doesn't show any issue with wget/ssh in the guest.

This has been tested on AMD Seattle, the guest kernel is the same on
every test (4KB page granularity).

I'm planning to give a try tomorrow on X-gene (ARM64 board and I think
64KB page granularity is supported) to see if I can reproduce the bug.

It's working on X-gene with the same kernel and configuration. I guess
we can deduce that it's a bug in the AMD network driver.

Regards,

-- 
Julien Grall