From mboxrd@z Thu Jan 1 00:00:00 1970 From: "James Harper" Subject: Re: [PATCH] xen-netfront: report link speed to ethtool Date: Sat, 19 Nov 2011 12:13:29 +1100 Message-ID: References: <20111118164805.GA14345@aepfle.de><1321638394.2883.32.camel@bwh-desktop><4EC6A778.1000503@hp.com> <201111182011.32318.pavel@netsafe.cz> <20111118193712.GQ12984@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-class: urn:content-classes:message In-Reply-To: <20111118193712.GQ12984@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?iso-8859-1?Q?Pasi_K=E4rkk=E4inen?= , Pavel Mat??ja Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org > The reported NIC speed in the VM does not mean anything really, because > it's all virtual "hardware", and the reported speed is not any kind of limit. > > Even if windows VM says it's 10 Mbit/sec NIC you can still talk as fast as your > system can go. > That's not quite true. Windows or some application might equate 10Mbit == WAN and do things a bit differently. BITS certainly scales back throughput but I think it does that based on actual tested throughput, although it might use the link speed as an indication. A HVM domain needs to report something because it is emulated hardware. A way to pass that through from Dom0 would be nice, but probably a lot of work for little gain vs just making up a reasonable figure. James