From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54156) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPsWj-00073Y-1h for qemu-devel@nongnu.org; Fri, 05 Sep 2014 08:22:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPsWa-0005AH-0m for qemu-devel@nongnu.org; Fri, 05 Sep 2014 08:22:04 -0400 Received: from mail-wg0-x22e.google.com ([2a00:1450:400c:c00::22e]:35568) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPsWZ-0005AA-Pj for qemu-devel@nongnu.org; Fri, 05 Sep 2014 08:21:55 -0400 Received: by mail-wg0-f46.google.com with SMTP id n12so737324wgh.17 for ; Fri, 05 Sep 2014 05:21:55 -0700 (PDT) Date: Fri, 5 Sep 2014 13:21:52 +0100 From: Stefan Hajnoczi Message-ID: <20140905122152.GF27649@stefanha-thinkpad.redhat.com> References: <20140903164417.GA32748@stefanha-thinkpad.redhat.com> <20140904220218.GA25871@grep.be> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tmoQ0UElFV5VgXgH" Content-Disposition: inline In-Reply-To: <20140904220218.GA25871@grep.be> Subject: Re: [Qemu-devel] NBD TLS support in QEMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wouter Verhelst Cc: Stefan Hajnoczi , libvir-list@redhat.com, nbd-general@lists.sf.net, qemu-devel@nongnu.org, Max Reitz , Hani Benhabiles , nick@bytemark.co.uk, Paolo Bonzini --tmoQ0UElFV5VgXgH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 05, 2014 at 12:02:18AM +0200, Wouter Verhelst wrote: > [Cc: to nbd-general list added] >=20 > On Wed, Sep 03, 2014 at 05:44:17PM +0100, Stefan Hajnoczi wrote: > > Besides QEMU, the userspace NBD tools (http://nbd.sf.net/) can also be > > extended to support TLS. In this case the kernel needs a localhost > > socket and userspace handles TLS. >=20 > That introduces a possibility for a deadlock, since now your network > socket isn't on the PF_MEMALLOC-protected socket anymore, which will > cause the kernel to throw away packets which are needed for your nbd > connection, in hopes of clearing some memory. Understood but there are plenty of use cases where this doesn't matter. Stefan --tmoQ0UElFV5VgXgH Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUCargAAoJEJykq7OBq3PI1SAH/3hjv3bwRrOzPdd7yKLW0tqB jPXsES5lEL6neAG970unpWJqxKPrPKOvVVo8V/NaTFuvEzCLh7erzNb6zsezXGge WnXVl4NuztjGqPf5+qZ0lMYBHn4UeBNLnpPkss9PgYMcPCPzM+xmB1ZtRJcpMi8S ThW1V2KA8uS4acHCaDuarmcpwAgZnYsa8WngNfoAXGABBVFG+xuxYKg0GE7Zkv44 1+rQrkuQTOS01KlbpkFkaqYucoLn9mqgA/ZVjA1+lTO9e9FSqVbOpOlk3Pt7sf7H psbNeAZmBRPxdHOaSuhum/YBbTYxqu5q+5iEcWq+XZTXBC01z4PP7JtoHaTJ7vc= =v63c -----END PGP SIGNATURE----- --tmoQ0UElFV5VgXgH--