Date: Thu, 19 Jul 2018 14:52:56 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= <royger@FreeBSD.org> 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> In-Reply-To: <ac2f232c-1834-f6b9-5852-f971fc8300ca@quip.cz> References: <20180719090444.jojyziar2c6wy735@mac> <ac2f232c-1834-f6b9-5852-f971fc8300ca@quip.cz>
next in thread | previous in thread | raw e-mail | index | archive | help
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.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20180719125256.fitjoii45ltkexgb>