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 00:01:00 +0200 Message-ID: <4A25A11C.3090700@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> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig277BC0D888957B5D1040ECA0" Cc: kvm@vger.kernel.org, avi@redhat.com To: Glauber Costa Return-path: Received: from fmmailgate01.web.de ([217.72.192.221]:42004 "EHLO fmmailgate01.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751088AbZFBWBF (ORCPT ); Tue, 2 Jun 2009 18:01:05 -0400 In-Reply-To: <20090602212340.GX30777@poweredge.glommer> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig277BC0D888957B5D1040ECA0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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 stat= e >> 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 of > the vcpu initialization. >=20 > 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 be nice to always see a consistent halted in user space, specifically for debugging purposes. Jan --------------enig277BC0D888957B5D1040ECA0 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 iEYEARECAAYFAkoloSAACgkQniDOoMHTA+k6LwCfXTz1M29wR1N9j6iSc/o5ZXUc re0An0TVS8ksxhPe4OuaqmXHpQA8T1/R =KSBs -----END PGP SIGNATURE----- --------------enig277BC0D888957B5D1040ECA0--