From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Metzmacher Subject: Re: [Patch v7 21/22] CIFS: SMBD: Upper layer performs SMB read via RDMA write through memory registration Date: Sun, 23 Sep 2018 23:24:27 +0200 Message-ID: References: <20171107085514.12693-1-longli@exchange.microsoft.com> <20171107085514.12693-22-longli@exchange.microsoft.com> <9b02dadb-d21b-7a8d-7803-910041f66047@talpey.com> <699de6ba-201a-fd4f-bcac-234e13f33afc@talpey.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="c5GHWwVHnxwpR9NKglrCRGV5nEI92Gmrw" Return-path: In-Reply-To: <699de6ba-201a-fd4f-bcac-234e13f33afc@talpey.com> Sender: linux-kernel-owner@vger.kernel.org To: Tom Talpey , Long Li , Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, Christoph Hellwig , Tom Talpey , Matthew Wilcox , Stephen Hemminger List-Id: linux-rdma@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --c5GHWwVHnxwpR9NKglrCRGV5nEI92Gmrw Content-Type: multipart/mixed; boundary="B64A0tmpOHUCJVaPx9ryigimzaEGy1bjp"; protected-headers="v1" From: Stefan Metzmacher To: Tom Talpey , Long Li , Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, Christoph Hellwig , Tom Talpey , Matthew Wilcox , Stephen Hemminger Message-ID: Subject: Re: [Patch v7 21/22] CIFS: SMBD: Upper layer performs SMB read via RDMA write through memory registration References: <20171107085514.12693-1-longli@exchange.microsoft.com> <20171107085514.12693-22-longli@exchange.microsoft.com> <9b02dadb-d21b-7a8d-7803-910041f66047@talpey.com> <699de6ba-201a-fd4f-bcac-234e13f33afc@talpey.com> In-Reply-To: <699de6ba-201a-fd4f-bcac-234e13f33afc@talpey.com> --B64A0tmpOHUCJVaPx9ryigimzaEGy1bjp Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Tom, >> I just tested that setting: >> >> mr->iova &=3D (PAGE_SIZE - 1); >> mr->iova |=3D 0xFFFFFFFF00000000; >> >> after the ib_map_mr_sg() and before doing the IB_WR_REG_MR, seems to >> work. >=20 > Good! As you know, we were concerned about it after seeing that > the ib_dma_map_sg() code was unconditionally setting it to the > dma_mapped address. By salting those FFFF's with varying data, > this should give your FRWR regions stronger integrity in addition > to not leaking kernel "addresses" to the wire. Just wondering... Isn't the thing we use called FRMR? metze --B64A0tmpOHUCJVaPx9ryigimzaEGy1bjp-- --c5GHWwVHnxwpR9NKglrCRGV5nEI92Gmrw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEfFbGo3YXpfgryIw9DbX1YShpvVYFAluoBI8ACgkQDbX1YShp vVaXdg//ZEmZRIkzmO40yTTKvzu9rkTAhOYXM2ifY0CFIEj1KdjTwYVaktGYrYMs UYsLQgMvsFAz1DUJx/VkwNlpPsKq5zJyeSDKojAwTw/keVZ8/VgOXM4bytUrgFU8 gsaiXyreXhGpdqVzIvECFAeOD0TRnD0COM2FfBWF9YxnuHH9iH4+7TfSBVSjImAV 0dUWTGn81v117FzTCC6lMXJuySrV4X4cHdfK00FVxgMO8BNuA6Z61GA26foUrWRL gwdYfHYRoMbD0F4qNw2+ggXifEwmhicUnLIGlXo0mnC7ercNFnBwG+sQLpaCdfJH ti2YYM5NEHQm8dwufM/nD+Ogabs/Y48YMor/6Dp9S+JaVxXiAy5gJgQALhyAVRQj kC8zn3hKvNSHG/h2LSzEdBtFbPouiSkh0j2OgmaN6bTJ1bnQKR3IUsApTDWdNCgf W3Az98N3NgDPFe4zLW/poLX3p8fapHrQa1pB3z6Txtlk9N/B3Dtuk6govGmCEvcI xSQCri0o12NNKKsGm3M86XK6iiQlMGGLE/h/4z+3CTytlPfhm0KI7gKETKuQg6xU 2RD9dl/Iv0luuhejxKjjcytf8dYw/dEbtV3vxOTiZ2bsAbZUzE2osBm9sThhau7r CdSTialSHXOA1xVtIaO68rgqdwMhODYUMOVbjGgh9ahkTqJWUN0= =lpBp -----END PGP SIGNATURE----- --c5GHWwVHnxwpR9NKglrCRGV5nEI92Gmrw--