From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54841) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sh0eK-0003Ne-Gc for qemu-devel@nongnu.org; Tue, 19 Jun 2012 11:47:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Sh0eC-0006bj-Rw for qemu-devel@nongnu.org; Tue, 19 Jun 2012 11:47:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:5847) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sh0eC-0006aa-KB for qemu-devel@nongnu.org; Tue, 19 Jun 2012 11:47:16 -0400 Message-ID: <4FE09EE3.9070603@redhat.com> Date: Tue, 19 Jun 2012 09:46:43 -0600 From: Eric Blake MIME-Version: 1.0 References: <1339689305-27031-1-git-send-email-coreyb@linux.vnet.ibm.com> In-Reply-To: <1339689305-27031-1-git-send-email-coreyb@linux.vnet.ibm.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enigA4F4F405D35B2B7DC6AD54B9" Subject: Re: [Qemu-devel] [PATCH v3 0/5] file descriptor passing using pass-fd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Corey Bryant Cc: kwolf@redhat.com, aliguori@us.ibm.com, stefanha@linux.vnet.ibm.com, libvir-list@redhat.com, Jeff Cody , qemu-devel@nongnu.org, Luiz Capitulino , pbonzini@redhat.com This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigA4F4F405D35B2B7DC6AD54B9 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 06/14/2012 09:55 AM, Corey Bryant wrote: > This patch series adds the pass-fd QMP monitor command, which allows > an fd to be passed via SCM_RIGHTS, and returns the received file > descriptor. Support is also added to the block layer to allow QEMU > to dup the fd when the filename is of the /dev/fd/X format. This > is useful if MAC policy prevents QEMU from opening specific types > of files. Something to think about on how this will interact with Jeff's work on block-commit. That is an interface where qemu must reopen backing files which were previously O_RDONLY to now be O_RDWR. By default (when open() is supported in qemu, and qemu is using the actual file name), this means 'block-commit' works without needing any fd names. But with this new fd-passing approach, a file originally opened as O_RDONLY /dev/fd/21 will need to be reopened, but the reopened fd will (likely) not be 21. In other words, we need to make sure 'block-commit' supports the ability to pass in optional arguments that specify the file name of the backing file to be reopened, so that libvirt can pass in O_RDWR fds to replace the existing O_RDONLY fd, and be aware that the /dev/fd/nn naming of the reopen will be different. --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enigA4F4F405D35B2B7DC6AD54B9 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJP4J7jAAoJEKeha0olJ0Nqh5MH/2qtXJCTjWUq6zqQzVmoJXwG FzD6cNx80eB+tiBZ3puRWPWrgETYhQ4HMKKvlX0OzpbL+CUCphOeZRwttQTJEBiZ 3IE+JcEd4vWn5X44VS11RVq0QfCW3zvEV3PnhEvpFwnvGpsYLEUF/DhThjALKW8Z AdMctILIoEskIzKLlfSL6WDL1NMFzYDCWkflCj6/wtaxZVesNuGwNuqu13KMiSmC N6yOcybpnlj0dvZpo+iFFCLShw+B+fZ3uWbTODv1FZzvoX4g1PsEOPBtwCnvnt4R h6m8VVPQPx/R4EyeZyOzISC+Vm8/YjGCVHdsZ+PBT5QQpQXCFTHeJvU3MC5U7wI= =veP4 -----END PGP SIGNATURE----- --------------enigA4F4F405D35B2B7DC6AD54B9--