On Tue, Jul 24, 2012 at 01:45:24PM -0700, Nicholas A. Bellinger wrote: > 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 <nab@xxxxxxxxxxxxxxx> > > > > > > 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 <aliguori@xxxxxxxxxx> > > > Cc: Stefan Hajnoczi <stefanha@xxxxxxxxxxxxxxxxxx> > > > Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> > > > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > > Cc: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx> > > > Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> > > > --- > > > drivers/vhost/tcm_vhost.c | 9 +++++++++ > > > drivers/vhost/tcm_vhost.h | 11 +++++++++++ > > > 2 files changed, 20 insertions(+), 0 deletions(-) > > > > > <SNIP> > > > > 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 <linux/vhost.h> > > > > > > +/* > > > + * 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. There is no real user base beyond the handful of people who have hacked on this. Adding the GET_ABI_VERSION ioctl() at this stage is fine, especially considering that the userspace code that talks to tcm_vhost isn't in mainline in userspace yet either. Stefan -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html