From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [kvm-devel] QEMU PIC indirection patch for in-kernel APIC work Date: Thu, 05 Apr 2007 10:17:40 +0300 Message-ID: <4614A294.3000607@qumranet.com> References: <4613B438.60107@codemonkey.ws> <4613B89F.8090806@qumranet.com> <4613BC6B.1070708@codemonkey.ws> <4613BF07.50606@qumranet.com> <4613C993.9020405@codemonkey.ws> <4613CC01.1090500@qumranet.com> <4613CDB2.4000903@codemonkey.ws> <4613D001.3040606@qumranet.com> <20070404200112.GA6070@elte.hu> <4614098F.2030307@us.ibm.com> <20070404212103.GA19026@elte.hu> <1175728768.12230.593.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7BIT Cc: Ingo Molnar , kvm-devel@lists.sourceforge.net, netdev To: Rusty Russell Return-path: Received: from mtaout4.012.net.il ([84.95.2.10]:56570 "EHLO mtaout4.012.net.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbXDEHRm (ORCPT ); Thu, 5 Apr 2007 03:17:42 -0400 Received: from firebolt.argo.co.il ([80.178.163.252]) by i_mtaout4.012.net.il (HyperSendmail v2004.12) with ESMTP id <0JG000L8SKNIFI00@i_mtaout4.012.net.il> for netdev@vger.kernel.org; Thu, 05 Apr 2007 10:26:06 +0300 (IDT) In-reply-to: <1175728768.12230.593.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Rusty Russell wrote: > You didn't quote Anthony's point about "it's more about there not being > good enough userspace interfaces to do network IO." > > It's easier to write a kernel-space network driver, but it's not > obviously the right thing to do until we can show that an efficient > packet-level userspace interface isn't possible. I don't think that's > been done, and it would be interesting to try. > In the case of networking, the copyful interfaces on receive are driven by the hardware not knowing how to split the header from the data. On transmit I agree, it could be made copyless from userspace (somthing like sendfilev, only not file oriented). -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.