From owner-freebsd-xen@freebsd.org Thu Jul 19 12:53:08 2018 Return-Path: Delivered-To: freebsd-xen@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0B9641033B74 for ; Thu, 19 Jul 2018 12:53:08 +0000 (UTC) (envelope-from royger@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id B078B8F6F8; Thu, 19 Jul 2018 12:53:07 +0000 (UTC) (envelope-from royger@FreeBSD.org) Received: from localhost (49.red-88-3-118.dynamicip.rima-tde.net [88.3.118.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: royger) by smtp.freebsd.org (Postfix) with ESMTPSA id CABF82608F; Thu, 19 Jul 2018 12:53:06 +0000 (UTC) (envelope-from royger@FreeBSD.org) Date: Thu, 19 Jul 2018 14:52:56 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Miroslav Lachman <000.fbsd@quip.cz> Cc: freebsd-xen@freebsd.org Subject: Re: HEADS UP: merged PVHv2 support and future plans Message-ID: <20180719125256.fitjoii45ltkexgb@mac> References: <20180719090444.jojyziar2c6wy735@mac> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20180512 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Jul 2018 12:53:08 -0000 On Thu, Jul 19, 2018 at 02:03:00PM +0200, Miroslav Lachman wrote: > Roger Pau Monné wrote on 2018/07/19 11:04: > > Hello, > > > > Today I've merged PVHv2 support into FreeBSD, allowing FreeBSD to be > > used as a PVHv2 DomU and Dom0. While it's not a huge set of changes, > > I would *really* appreciate if people could test the code starting > > from r336474 (or any later changeset). > > > > I expect there's going to be some confusion with PVHv1 vs PVHv2, so I > > will try to clarify this now. PVHv1 was introduced ~4 years ago, and > > at the time it seemed like a good way to move forward, allowing Xen to > > rely more on hardware virtualization. Later on, we sadly discovered > > that PVHv1 was still too similar to classic PV, and didn't allow Xen > > to make use of all the possible hardware virtualization extensions, so > > PVHv2 was introduced ~2 years ago as a replacement for PVHv1. PVHv2 > > ABI however is not compatible with PVHv1, which means that different > > entry points and interfaces must be used to interact with the > > hypervisor. > > > > After introducing PVHv2 PVHv1 was deprecated and PVHv1 has been > > removed from the hypervisor in recent versions, that's why the Xen > > ports package is still stuck with Xen 4.7, because later versions > > removed PVHv1 support. With the addition of PVHv2 to FreeBSD the port > > can be updated to newer Xen versions and we can move forward. > > > > There will be issues however, as newer versions of Xen won't have > > support for PVHv1. My plan is the following in order to try to make > > this less painful for users: > > > > - Wait until FreeBSD 12 is released, which will contain PVHv1 and > > PVHv2 support. > > - Once FreeBSD 12 has been released, update the Xen port to the > > latest version. > > What about creating new port as xen410 (for version 4.10) or repocopy of the > old one to xen47 to allow coexist of two different versions in the ports > tree and allow user to choose the right one for their OS version? I wondered about that, I will try to do it, but I have to admit my time is quite limited and I'm not sure I will be able to keep both up to data. Thanks, Roger.