From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 1/4] always halt non-bsp cpu. Date: Wed, 03 Jun 2009 00:32:04 +0200 Message-ID: <4A25A864.2070006@web.de> References: <1243971470-31676-1-git-send-email-glommer@redhat.com> <1243971470-31676-2-git-send-email-glommer@redhat.com> <4A258D23.9080106@web.de> <20090602212340.GX30777@poweredge.glommer> <4A25A11C.3090700@web.de> <20090602220937.GY30777@poweredge.glommer> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig097B45234BD5C72DB4EAE5AC" Cc: kvm@vger.kernel.org, avi@redhat.com To: Glauber Costa Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:35164 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752052AbZFBWcH (ORCPT ); Tue, 2 Jun 2009 18:32:07 -0400 In-Reply-To: <20090602220937.GY30777@poweredge.glommer> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig097B45234BD5C72DB4EAE5AC Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Glauber Costa wrote: > On Wed, Jun 03, 2009 at 12:01:00AM +0200, Jan Kiszka wrote: >> Glauber Costa wrote: >>> On Tue, Jun 02, 2009 at 10:35:47PM +0200, Jan Kiszka wrote: >>>> Glauber Costa wrote: >>>>> This is not kvm specific, and should do fine in plain qemu >>>> This is fine with plain qemu already. The problem, IIUC, is that >>>> in-kernel kvm irqchip does not have a chance to remove the halted st= ate >>>> again. Did you test the effect of this patch on that scenario? What >>>> makes it safe to be removed now? >>> IIRC, the in kernel irqchip sets halted =3D 0 in the very beginning o= f >>> the vcpu initialization. >>> >>> It is tested here with in-kernel irqchip and works, so probably not >>> a problem, unless you can spot something. >> At least your patch applied alone breaks -smp >1 here. >> >> But the whole management of env->halted for the in-kernel irqchip in >> qemu-kvm is a bit hacky IMHO. Maybe it's time to rethink this. Would b= e >> nice to always see a consistent halted in user space, specifically for= >> debugging purposes. > out of curiosity: did you apply the whole series? Meanwhile I did, but it makes no difference. >=20 > please report with it. I suspect there is a change later on that might > make it work. Of course, this is no excuse, as I'm a huge fan of bisect= ability. > If this is the case, I'll rework the series in a way that it always wor= k. I still suspect that dealing with halted for the in-kernel case is a bit more tricky. Jan --------------enig097B45234BD5C72DB4EAE5AC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkolqGcACgkQniDOoMHTA+nz8wCdHx4oi14T04v+xjYoFvN3Rg/+ KdwAniaGpyugFRMERQzEQlqfwTiOA6ph =ROaO -----END PGP SIGNATURE----- --------------enig097B45234BD5C72DB4EAE5AC--