From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH RFC v1 00/14] xen: arm: support for save restore and dead migration Date: Wed, 9 Dec 2015 15:51:20 +0000 Message-ID: <56684DF8.7030507@citrix.com> References: <1449671507.16124.264.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1449671507.16124.264.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Stefano Stabellini , "julieng julien.grall"@citrix.com, ian.jackson@eu.citrix.com, Wei Liu Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 09/12/15 14:31, Ian Campbell wrote: > For arm32 + gicv2 systems the following supports apparently successful > save/restore as well dead migrate a domain. > > There are several caveats/blockers, hence RFC. > > * GIC v2 support only, no GIC v3 at all > * ARM32 only. Doesn't even build for ARM64 (vfp state handling needs > adjustment) > * No live migration, only "dead" (no logdirty support yet) > * Have not fully audited the set of state which needs to be saved (i.e. I > might have missed some registers or something) > > On the flip side, thanks to migration v2 the toolstack side of this > practically trivial. Glad to hear this. > This is (of course) using the current Xen hvm blob handling strata, which I > believe there are plans afoot to rework along the lines of the libxc/libxl > migration v2 protocol. Yes - I have plans as part of fixing cpuid handling for x86. > > For now I have no problem waiting and reworking in that vein as things > progress, clearly the blockers/caveats (logdirty support in particular) are > going to take some time to sort out. > This is all based (very distantly) on some original patches from Evgeny > Fedotov and Junghyun Yoo (both of Samsung) however very little of that code > remains here. > > As well as the Xen series there will be a single Linux patch too, I'll only > CC ARM folks on that one. Something towards the end of this series should update docs/features/migration.pandoc to indicate the presence of ARM support. ~Andrew