From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:37841) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Stlz0-0003ON-D1 for qemu-devel@nongnu.org; Tue, 24 Jul 2012 16:45:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Stlyy-0001Cp-Sg for qemu-devel@nongnu.org; Tue, 24 Jul 2012 16:45:30 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:39616 helo=linux-iscsi.org) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Stlyy-0001CV-MI for qemu-devel@nongnu.org; Tue, 24 Jul 2012 16:45:28 -0400 From: "Nicholas A. Bellinger" In-Reply-To: <20120724015634.GD4093@kroah.com> References: <1343093180-5598-1-git-send-email-nab@linux-iscsi.org> <20120724015634.GD4093@kroah.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 24 Jul 2012 13:45:24 -0700 Message-ID: <1343162724.1813.111.camel@haakon2.linux-iscsi.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] tcm_vhost: Expose ABI version via VHOST_SCSI_GET_ABI_VERSION List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Greg Kroah-Hartman Cc: Jens Axboe , Stefan Hajnoczi , kvm-devel , "Michael S. Tsirkin" , Zhi Yong Wu , qemu-devel , lf-virt , Anthony Liguori , target-devel , Hannes Reinecke , linux-scsi , Paolo Bonzini , Zhi Yong Wu , Christoph Hellwig , Avi Kivity On Mon, 2012-07-23 at 18:56 -0700, Greg Kroah-Hartman wrote: > On Tue, Jul 24, 2012 at 01:26:20AM +0000, Nicholas A. Bellinger wrote: > > From: Nicholas Bellinger > > > > As requested by Anthony, here is a patch against target-pending/for-next-merge > > to expose an ABI version to userspace via a new VHOST_SCSI_GET_ABI_VERSION > > ioctl operation. > > > > As mentioned in the comment, ABI Rev 0 is for pre 2012 out-of-tree code, and > > ABI Rev 1 (the current rev) is for current WIP v3.6 kernel merge candiate code. > > > > I think this is what you had in mind, and hopefully it will make MST happy too. > > The incremental vhost-scsi patches against Zhi's QEMU are going out shortly ahead > > of cutting a new vhost-scsi RFC over the next days. > > > > Please have a look and let me know if you have any concerns here. > > > > Thanks! > > > > Reported-by: Anthony Liguori > > Cc: Stefan Hajnoczi > > Cc: Michael S. Tsirkin > > Cc: Paolo Bonzini > > Cc: Zhi Yong Wu > > Signed-off-by: Nicholas Bellinger > > --- > > drivers/vhost/tcm_vhost.c | 9 +++++++++ > > drivers/vhost/tcm_vhost.h | 11 +++++++++++ > > 2 files changed, 20 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h > > index e942df9..3d5378f 100644 > > --- a/drivers/vhost/tcm_vhost.h > > +++ b/drivers/vhost/tcm_vhost.h > > @@ -80,7 +80,17 @@ struct tcm_vhost_tport { > > > > #include > > > > +/* > > + * Used by QEMU userspace to ensure a consistent vhost-scsi ABI. > > + * > > + * ABI Rev 0: All pre 2012 revisions used by prototype out-of-tree code > > + * ABI Rev 1: 2012 version for v3.6 kernel merge candiate > > + */ > > + > > +#define VHOST_SCSI_ABI_VERSION 1 > > + > > struct vhost_scsi_target { > > + int abi_version; > > unsigned char vhost_wwpn[TRANSPORT_IQN_LEN]; > > unsigned short vhost_tpgt; > > }; > > @@ -88,3 +98,4 @@ struct vhost_scsi_target { > > /* VHOST_SCSI specific defines */ > > #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target) > > #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target) > > +#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, struct vhost_scsi_target) > > No, you just broke the ABI for version "0" here, that's not how you do > this at all. > The intention of this patch is use ABI=1 as a starting point for tcm_vhost moving forward, with no back-wards compat for the ABI=0 prototype userspace code because: - It's based on a slightly older version of QEMU (updating the QEMU series now) - It does not have an GET_ABI_VERSION ioctl cmd (that starts with ABI=1) - It has a small user-base of target + virtio-scsi developers So I did consider just starting from ABI=0, but figured this would help reduce the confusion for QEMU userspace wrt to the vhost-scsi code that's been floating around out-of-tree for the last 2 years. Stefan & Co folks, do you have a preference for a starting point..? Thanks, --nab