From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: VMX: Fix locking order in handle_invalid_guest_state Date: Sun, 26 Jul 2009 16:55:56 +0200 Message-ID: <4A6C6E7C.2070000@web.de> References: <4A678A56.7050901@web.de> <20090723214553.GA10152@amt.cnet> <4A695C1D.7030807@web.de> <4A6C5F4B.2000902@redhat.com> <4A6C66F2.7010606@web.de> <4A6C69F5.3020604@redhat.com> <4A6C6A74.4030801@web.de> <4A6C6C74.4040808@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig4ED779A40E9EC046D6FC5EE3" Cc: Marcelo Tosatti , kvm-devel To: Avi Kivity Return-path: Received: from fmmailgate01.web.de ([217.72.192.221]:59508 "EHLO fmmailgate01.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753591AbZGZOz5 (ORCPT ); Sun, 26 Jul 2009 10:55:57 -0400 In-Reply-To: <4A6C6C74.4040808@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig4ED779A40E9EC046D6FC5EE3 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Avi Kivity wrote: > On 07/26/2009 05:38 PM, Jan Kiszka wrote: >> Avi Kivity wrote: >> =20 >>> On 07/26/2009 05:23 PM, Jan Kiszka wrote: >>> =20 >>>>> btw, what does it fix? a debug warning? >>>>> >>>>> >>>>> =20 >>>> I haven't seen anything in the wild, and I don't think it would rais= e a >>>> warning. All it should cause is a potential delay of some pending >>>> reschedule as preempt_enable will not fire under local_irq_disable. >>>> >>>> =20 >>> Ah, okay, then it is a real fix. Preempt-correctness is important. >>> >>> (but won't local_irq_enable() reschedule?) >>> =20 >> >> The last time I checked it was essentially a plain 'sti'. >> >> =20 >=20 > Presumably there's a reschedule interrupt queued; I think if you set th= e > reschedule bit you have to IPI the cpu running the task. >=20 Yeah. But as we preempt_disable first, that one might have been processed already. Jan --------------enig4ED779A40E9EC046D6FC5EE3 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 iEYEARECAAYFAkpsbnwACgkQniDOoMHTA+m9WwCfd8MdC52nczHjAtYz4ebvxIyS 5I8Ani5PPpisFeet0nh2mpHmjnHPZj4p =pAq4 -----END PGP SIGNATURE----- --------------enig4ED779A40E9EC046D6FC5EE3--