From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45228) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dahCg-0002RU-F6 for qemu-devel@nongnu.org; Thu, 27 Jul 2017 07:43:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dahCf-000385-Ge for qemu-devel@nongnu.org; Thu, 27 Jul 2017 07:43:42 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:56925) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dahCe-000346-T1 for qemu-devel@nongnu.org; Thu, 27 Jul 2017 07:43:41 -0400 Date: Thu, 27 Jul 2017 20:53:48 +1000 From: David Gibson Message-ID: <20170727105348.GG7970@umbus.fritz.box> References: <1501119055-4060-1-git-send-email-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="eVzOFob/8UvintSX" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH for-2.10 0/3] qdev/vfio: defer DEVICE_DEL to avoid races with libvirt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Michael Roth , QEMU Developers , "Daniel P. Berrange" , Alex Williamson , Paolo Bonzini , Greg Kurz , Markus Armbruster --eVzOFob/8UvintSX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 27, 2017 at 10:11:48AM +0100, Peter Maydell wrote: > On 27 July 2017 at 02:30, Michael Roth wrote: > > In particular, Mellanox CX4 adapters on PowerNV hosts might not be fully > > quiesced by vfio-pci's finalize() routine until up to 6s after the > > DEVICE_DELETED was emitted, leading to detach-device on the libvirt sid= e pretty > > much always crashing the host. >=20 > My initial naive thought is that if the host kernel can crash then > this is a host kernel bug... shouldn't the host kernel refuse > the subsequent libvirt rebind if it would cause a crash ? I think so too, but I haven't been able to convince Alex. Nor find time to fix it in the kernel myself. --=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 --eVzOFob/8UvintSX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAll5xjoACgkQbDjKyiDZ s5I7AxAAkE9dAgjb7/sE9FD4yeqJoAs+RQbt5in3F6HqWlP6TlIKiB3L3WWRxZi9 v4R3gRMRoL5WAHKqmpNqdRprdzUltKttAvJ25UDYkJJ63aYGawDkFbRtSbo/zSKT DaSBoL8R5GeVwdhUePWT1v7/UiJXbqqjF3nrTy0E/aNTMp33X31PtCHGWayM+YQj OobHL3zXCgCVpYrccFIJF0dH/UHy1Nv4E84eH6CQmunioyUBrLECDq+QBZBhTr3Z JZ/FAVdw3IY91r1tA55W8IyIsbz7lxfVcUdn1thhv+mU35LUUNMY5YruW9asJ46Z TpldsBPW8AXZ7LEmXo4xqPNJWSsluODv+5R258bWS8LoFKj6nUirHuP4Ubrh0Lmv 9XulykAv+SbUFuS2caGSFoLqgGHnc+ZoTh7Xlows40DBmx/XtFhePoBVBcPAL6G3 IeVEsSmAJQubnNRY4oDXm9Lac5wXE8kATYCTXKYLg/dyOcUSOr4OlKg9jFbMjMzV j1Q25iJc2q0DHBbYy7VBA69R4qrorRnTuVfb6Fi36rOMbEwuO1gosmzAK2rMrYZ6 vFORJuEmycGwbwwNXOrkz6JfPWHtCtfPD7j1Ge8xjcCnlJKi9Khichqj9+mtx7E3 DxjXsgBHI0dIeFszqjV/WJ8gskqbG0Ky2G3+uhq3Qy36k1A5G1Y= =FlMg -----END PGP SIGNATURE----- --eVzOFob/8UvintSX--