From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [RFC 21/23] net/xen-netback: Make it running on 64KB page granularity Date: Wed, 20 May 2015 15:29:19 +0100 Message-ID: <555C9A3F.7000207__23264.288766268$1432132452$gmane$org@citrix.com> References: <1431622863-28575-1-git-send-email-julien.grall@citrix.com> <1431622863-28575-22-git-send-email-julien.grall@citrix.com> <20150515023534.GE19352@zion.uk.xensource.com> <5555E81E.8070803@citrix.com> <20150515153143.GA8521@zion.uk.xensource.com> <5559D6EE.3030400@citrix.com> <20150518125406.GA9503@zion.uk.xensource.com> <555BBFA7.8030502@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Yv52W-0004yp-QR for xen-devel@lists.xenproject.org; Wed, 20 May 2015 14:32:08 +0000 In-Reply-To: <555BBFA7.8030502@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall , Wei Liu , ian.campbell@citrix.com Cc: stefano.stabellini@eu.citrix.com, netdev@vger.kernel.org, tim@xen.org, linux-kernel@vger.kernel.org, Suravee Suthikulpanit , xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org List-Id: xen-devel@lists.xenproject.org On 19/05/15 23:56, Julien Grall wrote: >> 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