From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36230) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1brlhM-0003W2-68 for qemu-devel@nongnu.org; Wed, 05 Oct 2016 08:53:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1brlhH-0000CG-5Q for qemu-devel@nongnu.org; Wed, 05 Oct 2016 08:53:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12693) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1brlhG-0000CA-SL for qemu-devel@nongnu.org; Wed, 05 Oct 2016 08:53:19 -0400 Date: Wed, 5 Oct 2016 13:53:16 +0100 From: Stefan Hajnoczi Message-ID: <20161005125316.GC863@stefanha-x1.localdomain> References: <1475051152-400276-1-git-send-email-arei.gonglei@huawei.com> <1475051152-400276-5-git-send-email-arei.gonglei@huawei.com> <20161003163140.GX10245@stefanha-x1.localdomain> <33183CC9F5247A488A2544077AF19020B03E658A@SZXEMA503-MBS.china.huawei.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="f+W+jCU1fRNres8c" Content-Disposition: inline In-Reply-To: <33183CC9F5247A488A2544077AF19020B03E658A@SZXEMA503-MBS.china.huawei.com> Subject: Re: [Qemu-devel] [PATCH v4 04/13] cryptodev: introduce a new cryptodev backend List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Gonglei (Arei)" Cc: "qemu-devel@nongnu.org" , "virtio-dev@lists.oasis-open.org" , Luonengjun , "mst@redhat.com" , "pbonzini@redhat.com" , "berrange@redhat.com" , "Huangweidong (C)" , "Wubin (H)" , "mike.caraman@nxp.com" , "agraf@suse.de" , "xin.zeng@intel.com" , Claudio Fontana , "nmorey@kalray.eu" , "vincent.jardin@6wind.com" , "Zhoujian (jay, Euler)" , "Hanweidong (Randy)" , "Huangpeng (Peter)" --f+W+jCU1fRNres8c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 05, 2016 at 03:19:44AM +0000, Gonglei (Arei) wrote: > > -----Original Message----- > > From: Stefan Hajnoczi [mailto:stefanha@redhat.com] > > Sent: Tuesday, October 04, 2016 12:32 AM > > Subject: Re: [PATCH v4 04/13] cryptodev: introduce a new cryptodev back= end > >=20 > > On Wed, Sep 28, 2016 at 04:25:43PM +0800, Gonglei wrote: > > > +/* Max number of symetrical sessions */ > >=20 > > s/symetrical/symmetric/ > >=20 > > But why does the comment say "symetrical" when the constant name > > MAX_NUM_SESSIONS seems to be a global limit for *all* sessions (not just > > symmetric)? > >=20 > > > +#define MAX_NUM_SESSIONS 256 > >=20 > > The guest can only have 256 sessions open? > >=20 > For cipher API backend, it's a experimental cryptodev backend, which > can't be applied in production environment because of the poor performanc= e.=20 > The limit is just for simplifying code logic, of course we can increase t= he number > as well, but it doesn't necessary IMO. >=20 > > What are the limits of real crypto libraries and accelerators? > >=20 > The hardware accelerators maybe have a limit, for example the > Intel QAT pmd driver in DPDK limit the maximum num of session is 2048. How do we prevent competing guests from creating idle sessions ahead of time in order to "reserve" them? Greedy guests could prevent other guests from creating sessions if the hardware limit is 2048. Perhaps the max sessions limit should be a user parameter so the host administrator use it to guarantee session availability. --f+W+jCU1fRNres8c Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJX9Pe8AAoJEJykq7OBq3PIEwwH/iKDkJ2yivljHfy/xA+keZjZ Iyf+1DKhtCBR+Aft7QWL2u4Bj3KcaQG68oCsx3DeAvFy5zqrJcFNBuA8v+nBHHqW wxQf/o9yrnPYXmFzQHcRKnUj2Yg1UR2DT3cwamy5C19n4FHGYUOeBQ7j3kI8Qh0f T/5qoDHAxlu6zKW1aLM7X0FAjuG06oa1gYHjyypyQxO8cn96WpqevmJvtjzwGSQu cWnPSAUkU4JcB3W3WMU9GE/1zU0zzyH4gPEazZY1mhNQkR4vTPbtP1LkvsW/fZlM ewD0gmQSGRnB62S+zm9aVQ98mrJJx9v+k8bw0qZZBjdQBcCGkKoLHe0oV4gWYEQ= =RHGD -----END PGP SIGNATURE----- --f+W+jCU1fRNres8c--