From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [kvm-unit-tests PATCH 11/14] powerpc/ppc64: add rtas_power_off Date: Wed, 5 Aug 2015 10:06:05 +1000 Message-ID: <20150805000605.GC7739@voom.redhat.com> References: <1438612891-3718-1-git-send-email-drjones@redhat.com> <1438612891-3718-12-git-send-email-drjones@redhat.com> <55BFA001.6070900@redhat.com> <20150804040952.GE3080@voom.redhat.com> <20150804074759.GD13384@hawk.localdomain> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7gGkHNMELEOhSGF6" Cc: Paolo Bonzini , kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, dgibson@redhat.com, agraf@suse.de, thuth@redhat.com, lvivier@redhat.com To: Andrew Jones Return-path: Received: from ozlabs.org ([103.22.144.67]:52787 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752952AbbHEAOK (ORCPT ); Tue, 4 Aug 2015 20:14:10 -0400 Content-Disposition: inline In-Reply-To: <20150804074759.GD13384@hawk.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: --7gGkHNMELEOhSGF6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 04, 2015 at 09:47:59AM +0200, Andrew Jones wrote: > On Tue, Aug 04, 2015 at 02:09:52PM +1000, David Gibson wrote: > > On Mon, Aug 03, 2015 at 07:08:17PM +0200, Paolo Bonzini wrote: > > >=20 > > >=20 > > > On 03/08/2015 16:41, Andrew Jones wrote: > > > > Add enough RTAS support to support power-off, and apply it to > > > > exit(). > > > >=20 > > > > Signed-off-by: Andrew Jones > > >=20 > > > Why not use virtio-mmio + testdev on ppc as well? Similar to how we'= re > > > not using PSCI on ARM or ACPI on x86. > >=20 > > Strange as it seems, MMIO is actually a PITA for a simple pseries > > guest like this. Basically, you have to enable the MMU - which > > requires a whole bunch of setup - in order to perform cache-inhibited > > loads and stores, which is what you need for IO. > >=20 > > There are hypercalls to sidestep this (H_LOGICAL_CI_LOAD and > > H_LOGICAL_CI_STORE), but having a hypercall and KVM exit for every IO > > access may be hideously slow. > >=20 > > In early development we did have a hypercall mediated virtio model, > > but it was abandoned once we got PCI working. >=20 > So I think by yours and Alex's responses, if we want testdev support > then we should target using pci to expose it. Um.. maybe. I'm not really familiar with these testdevs, so I can't answer directly. > I'm ok with that, but > prefer not to be distracted with it while getting ppc kickstarted. > So, question for Paolo, are you OK with the exitcode snooper "cheat"? If you wanted to add a special hypercall channel for use by the tests I'd be ok with that too. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --7gGkHNMELEOhSGF6 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVwVNtAAoJEGw4ysog2bOSi3AQALmGvUQoPulwd4tHDQbdrdrg ODCx65BNXQ8qgm/BZuhO6SNuJ96X8FDoGxoFrGpmi1Qa1KXmKb0+VfnFLU86nZQq BB0pIovHIEorm5r85HSSc1JBTKk7GAgJLPhzIhR9WtDTH5r3kyoygEb8mUmEqDuV 9okimKqzA3Ip/Bb1V78VfzOVwAZ4v4pJV1eqJStb1vFvT31Y+2kEdKl/qxpFSGDS NOUVTgkMmj3n2jfDrU39sfXxywoH0wSneHT76hQi5HxvQMShQdUGyr09ClVNhIqd AEWhK6v+U+/JJ8bKqI7CNQnRqEc3MMg4kmLqUr1eNSp+g7945Eoep6kmxZOQIjAk n7zR4t1e+mG/vNkVcovGKpZwgN7PmQcTJ/EfPk2SFqpoSvDZbOdsLmei4sqS/x+S JVRgJahFnMMQTVkxNHgH6IlfhK5ATmwm8SVObYj1ny8W8hHBG31/vBWUr49DZrON xgTdfhZuSCuLJ51O1TS0KeA9bWF61dTXWxy3BR56/H3JZe/R/Y1EK8HZ3W8acECf U5jbSQQlOzzSz9ynI4mxqzB+qvtFDNc7Nzm1cwDhBKPkEUtJXTq0aleTnvdDsine A9nqsr46kY8hdWu+8q2jvQEqKrisRE0lGvNNt1OKkZhp0dtj3kUbav9vSuRapmMD ZLSGQiN1MYCODJstgNSs =e4K+ -----END PGP SIGNATURE----- --7gGkHNMELEOhSGF6--