From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 10 Jun 2013 19:14:52 +0200 (CEST) Received: from mail-ie0-f177.google.com ([209.85.223.177]:65359 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6835158Ab3FJROgsbSZN (ORCPT ); Mon, 10 Jun 2013 19:14:36 +0200 Received: by mail-ie0-f177.google.com with SMTP id u16so16239624iet.8 for ; Mon, 10 Jun 2013 10:14:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=4EYNFZo9lNFTIj9qk9m5ALZHpGtPbv55aY5xOXVXWHQ=; b=a7uMAU2nX7hXBpg8gFHdd7/mlva4uyTfkfTQGYS95eyAZ+CBzjdwzWSKT0DJSETjfI kQS0EF+JBx4vLWKHGFx3MoTn5TSTEjVJ640Ms3nvAF5uG9dK4Nl8smO5XgVfQJjBVyCE etl6bGS+rLDrdY+iKHVjTtDPqmunkblUQadQDE3082KusduKkHSAZkxQKRhzxEpKJsbk huYZVUjMsSOnvdWwtQ8d+Mm5h837kMyjyRlE1sCU9NYfoeTuhlM0CsqSeb/miAJYKUrI RR4BLwCa/WRWOZbqV6/bRSG1ydNAtEHuRWkd7o2mP8TF/0A6I8Pzu5nlmnNFuykyLG+o ygMQ== X-Received: by 10.50.55.39 with SMTP id o7mr3182032igp.86.1370884470398; Mon, 10 Jun 2013 10:14:30 -0700 (PDT) Received: from dl.caveonetworks.com (64.2.3.195.ptr.us.xo.net. [64.2.3.195]) by mx.google.com with ESMTPSA id r20sm8805885ign.8.2013.06.10.10.14.28 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 10 Jun 2013 10:14:29 -0700 (PDT) Message-ID: <51B60973.1080506@gmail.com> Date: Mon, 10 Jun 2013 10:14:27 -0700 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Sanjay Lal CC: linux-mips@linux-mips.org, ralf@linux-mips.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David Daney Subject: Re: [PATCH 00/31] KVM/MIPS: Implement hardware virtualization via the MIPS-VZ extensions. References: <1370646215-6543-1-git-send-email-ddaney.cavm@gmail.com> <8D7771A4-B51E-4FA8-9342-621FE41792DE@kymasys.com> In-Reply-To: <8D7771A4-B51E-4FA8-9342-621FE41792DE@kymasys.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 36811 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ddaney.cavm@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 06/10/2013 09:43 AM, Sanjay Lal wrote: > > On Jun 7, 2013, at 4:03 PM, David Daney wrote: > >> From: David Daney >> >> These patches take a somewhat different approach to MIPS >> virtualization via the MIPS-VZ extensions than the patches previously >> sent by Sanjay Lal. >> >> Several facts about the code: >> >> >> o Currently probably only usable on the OCTEON III CPU model, as some >> MIPS-VZ implementation-defined behaviors were assumed to have the >> OCTEON III behavior. >> > > > I've only briefly gone over the patches, but I was wondering if the Cavium implementation has support for GuestIDs, which are optional in the VZ-ASE? > No, OCTEON III does not support this optional behavior. For the most part this only impacts TLB management. I think in the context of KVM, you cannot leave foreign Guest's TLB entries present in the Guest TLB anyhow, so the feature is of little use. Since MIPS TLBs are managed by software, it is valid for a guest to populate the TLB in any way it desires. To have the hypervisor (KVM) come and randomly invalidate the TLB, via the GuestID mechanism, would both be detectable by the guest, and potentially make the guest operate incorrectly. David Daney > Regards > Sanjay > > > >