From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38218) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c7E9G-0001XG-8z for qemu-devel@nongnu.org; Wed, 16 Nov 2016 23:18:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c7E9E-0002Rt-Kf for qemu-devel@nongnu.org; Wed, 16 Nov 2016 23:18:06 -0500 Date: Thu, 17 Nov 2016 14:13:42 +1100 From: David Gibson Message-ID: <20161117031342.GC18808@umbus.fritz.box> References: <1479285571-28145-1-git-send-email-thuth@redhat.com> <20161116131321.35d58700@bahia> <20161116122450.GC2050@work-vm> <20161116133756.76854958@bahia> <2f74eb45-b36d-3d4d-5b47-f06259ade5c4@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="LwW0XdcUbUexiWVK" Content-Disposition: inline In-Reply-To: <2f74eb45-b36d-3d4d-5b47-f06259ade5c4@redhat.com> Subject: Re: [Qemu-devel] [PATCH] tests/postcopy: Use KVM on ppc64 only if it is KVM-HV List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: Greg Kurz , "Dr. David Alan Gilbert" , qemu-ppc@nongnu.org, Laurent Vivier , Stefan Hajnoczi , qemu-devel@nongnu.org, Andrea Arcangeli , Eric Blake --LwW0XdcUbUexiWVK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 16, 2016 at 02:17:47PM +0100, Thomas Huth wrote: > On 16.11.2016 13:37, Greg Kurz wrote: > > On Wed, 16 Nov 2016 12:24:50 +0000 > > "Dr. David Alan Gilbert" wrote: > >=20 > >> * Greg Kurz (groug@kaod.org) wrote: > >>> On Wed, 16 Nov 2016 09:39:31 +0100 > >>> Thomas Huth wrote: > >>> =20 > >>>> The ppc64 postcopy test does not work with KVM-PR, and it is also > >>>> causing annoying warning messages when run on a x86 host. So let's > >>>> use KVM here only if we know that we're running with KVM-HV (which > >>>> automatically also means that we're running on a ppc64 host), and > >>>> fall back to TCG otherwise. > >>>> =20 > >>> > >>> This patch addresses two issues actually: > >>> - the annoying warning when running on a ppc64 guest on a non-ppc64 h= ost > >>> - the fact that KVM-PR seems to be currently broken > >>> > >>> I agree that the former makes sense, but what about the case of runni= ng > >>> a x86 guest on a non-x86 host ? >=20 > Of course you also get these '"kvm" accelerator not found' messages > there. But so far, I think nobody complained about that yet (only for > ppc64 running on x86). And at least the test succeeds there - unlike > with KVM-PR, where the test fails completely. Well, I guess I should complain about them then. It is slightly irritating when doing my pre-pull tests on a ppc64 host, although I'm more or less used to it now. > >>> I'm still feeling uncomfortable with the KVM-PR case... is this a wor= karound > >>> we want to keep until we find out what's going on or are we starting = to > >>> partially deprecate KVM PR ? In any case, I guess we should document = this > >>> and probably print some meaningful error message. =20 > >> > >> This is certainly a work around for now, it doesn't suggest anything a= bout > >> deprecation. > >=20 > > Well it doesn't suggest anything actually, it just silently skips KVM P= R... > > I would at least expect a comment in the code mentioning this is a > > workaround and maybe an explicit warning for the user. If the user real= ly > > wants to run this test with KVM on ppc64, then she should ensure it is > > KVM HV. >=20 > Honestly, also considering the number of patches that Laurent already > wrote here and never have been accepted, all this has become quite an > ugly bike-shed painting discussion. >=20 > My opinion: >=20 > - If we want to properly test KVM (be it KVM-HV or KVM-PR), write > a proper kvm-unit-test instead. I.e. I personally don't care if this > test in QEMU is only run with TCG or with KVM. >=20 > - The current status of "make check" is broken, since it does not > work on KVM-PR. We've got to fix that before the release. >=20 > That means I currently really don't care if we've spill out a warning > message for KVM-PR here or not - sure, somebody just got to look at > KVM-PR later, but that's IMHO off-topic for the test here in the QEMU > context. >=20 > So if you think that the patch for fixing this issue here with the QEMU > test should look differently, please propose a different patch instead. > I'm fine with every other approach as long as we get this fixed in time > for QEMU 2.8. Hm, yeah, I concur.x >=20 > Thomas >=20 --=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 --LwW0XdcUbUexiWVK Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYLSBmAAoJEGw4ysog2bOSZx4QAMxrWCHZ7vfbIPM5gnatECNH 9F9EQa3JjR5/xR5gOssf5VFOgdUvyBAdWLcEJvvJTMW1mG8w5J6yC2JmFyt9aMG6 oJSRsCmjO2dxL7QyDEKPaiGJXC2kOLBEXAiYbiAEp38vkf+NKSxZn601/xokyNvX HRejq3TNLZYGFKF04sYP6YDhIvwe6ju0YGp9L8XnfZHXLiUEkiPQCtLUim2e+sYb +8ffA9v0/tYo/a5QlIr4yiUFyNX0cVsptvtShYfbHkQQSJx0nlypPKFvpn2Wyg+k b4FOJQqcTbDu+9yjjB75e/KiRXy4zOI/BrwI5cC3HgL3Z6NGhHk87C2v8iHu78Uf q92WfU8t407gJDXJzALjOltZdV9pB0tmn58bnQTpPQsvolNAVmMJSfZCbQ4eE/ku gmCy4CBFoYbroiD0kG5zibk6fEXwDM5BWCRVVIWjxS3nGv/mJw+ry7ZeN8PAb/95 ncm8IyK0/0ITEDRWW1jVM9sV5DjJlt1j/2c+BDFvu+O9SEBHf+NH8nSGjBSTG09T XYFnWWC0jbaHiCr+CoWILUaG0PRSOzbv2edTzD/NQemd+QXlxji6FNvG6C2sPAoI rHV9A5CRBTqYXZ2xqqbrLrVJjN7TMIlotexGJr3G/5BM/+Q9XQHM143VXVSD/97V m8Low/Y1YsT989a0De51 =7MVK -----END PGP SIGNATURE----- --LwW0XdcUbUexiWVK--