From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756736AbZFYNTs (ORCPT ); Thu, 25 Jun 2009 09:19:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752548AbZFYNTi (ORCPT ); Thu, 25 Jun 2009 09:19:38 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:36785 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbZFYNTh (ORCPT ); Thu, 25 Jun 2009 09:19:37 -0400 Message-ID: <4A43795D.1080501@novell.com> Date: Thu, 25 Jun 2009 09:19:25 -0400 From: Gregory Haskins User-Agent: Thunderbird 2.0.0.22 (Macintosh/20090605) MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Gregory Haskins , avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mtosatti@redhat.com, paulmck@linux.vnet.ibm.com, markmc@redhat.com Subject: Re: [PATCH] kvm: remove in_range from kvm_io_device References: <20090623150008.GA21059@redhat.com> <4A4184C3.6060503@novell.com> <20090624084901.GB22865@redhat.com> <20090625110812.GA6487@redhat.com> <4A435F28.3000301@novell.com> <20090625115403.GA7079@redhat.com> <4A4368A4.8030401@novell.com> <20090625123757.GA7121@redhat.com> <4A437564.6060308@novell.com> <20090625131633.GA7221@redhat.com> In-Reply-To: <20090625131633.GA7221@redhat.com> X-Enigmail-Version: 0.95.7 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig3E9AC9D57ACF7783ECDD3563" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig3E9AC9D57ACF7783ECDD3563 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Michael S. Tsirkin wrote: > On Thu, Jun 25, 2009 at 09:02:28AM -0400, Gregory Haskins wrote: > =20 >>> Here's what I have in mind: >>> kvm does >>> lock >>> dev =3D find >>> unlock >>> >>> <---------- at this point group device is removed >>> >>> write access to device that has been removed >>> >>> >>> =20 >>> =20 >> Hmm...you are right. This looks like it was introduced with that rece= nt >> locking patch you cited. Well, I can still fix it now easily by putti= ng >> an rcu-read-lock around the access. Longer term we should move to >> srcu. Thoughts? >> >> -Greg >> >> =20 > > > Some callbacks take kvm mutex lock. So it seems rcu won't work, > we need srcu. > > =20 Indeed. I will put something together. We should consider merging the io_bus cleanup I have for deregister support ASAP as well. -Greg --------------enig3E9AC9D57ACF7783ECDD3563 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkpDeV0ACgkQlOSOBdgZUxl8vQCfataqWJS2pHo62psffad0vmQM 6NQAn0+9fnfmgBylO9nPfbwFWXsfkOEQ =Lta8 -----END PGP SIGNATURE----- --------------enig3E9AC9D57ACF7783ECDD3563--