From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:35999) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1goVmg-0003mx-MM for qemu-devel@nongnu.org; Tue, 29 Jan 2019 10:58:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1goVmf-0000RF-Nv for qemu-devel@nongnu.org; Tue, 29 Jan 2019 10:58:46 -0500 Date: Tue, 29 Jan 2019 15:58:32 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20190129155832.GJ30796@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20190125174653.4604-1-kwolf@redhat.com> <20190125174653.4604-4-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190125174653.4604-4-kwolf@redhat.com> Subject: Re: [Qemu-devel] [PATCH 3/3] scsi-disk: Deprecate device_id fallback to BlockBackend name List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-block@nongnu.org, armbru@redhat.com, pbonzini@redhat.com, pkrempa@redhat.com, eblake@redhat.com, libvir-list@redhat.com, qemu-devel@nongnu.org On Fri, Jan 25, 2019 at 06:46:53PM +0100, Kevin Wolf wrote: > We should never have exposed BlockBackend names to the guest, it's a > host detail. Deprecate this behaviour. Users who need to maintain the > guest ABI can explicitly set the value with the device_id property. I don't think we've deprecated things in the past which would cause a guest ABI change when finally deleted. Shouldn't we be instead setting using machine type versioning here, so that existing machine types keep using the blk_name() fallback forever, while QEMU 4.0+ machine types avoid blk_name() fallback immediately. > Signed-off-by: Kevin Wolf > --- > hw/scsi/scsi-disk.c | 5 +++++ > qemu-deprecated.texi | 22 +++++++++++++++++++++- > 2 files changed, 26 insertions(+), 1 deletion(-) > > diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c > index e74e1e7c48..38f1fe2570 100644 > --- a/hw/scsi/scsi-disk.c > +++ b/hw/scsi/scsi-disk.c > @@ -2366,6 +2366,11 @@ static void scsi_realize(SCSIDevice *dev, Error **errp) > const char *str = blk_name(s->qdev.conf.blk); > if (str && *str) { > s->device_id = g_strdup(str); > + warn_report("Using the backend drive ID for the Device " > + "Identification VPD page is deprecated. " > + "Please specify the serial or device_id options " > + "explicitly to avoid guest-visible changes in " > + "future QEMU versions."); > } > } > } Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|