From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60860) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dIZjz-0002dS-K1 for qemu-devel@nongnu.org; Wed, 07 Jun 2017 08:07:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dIZjv-0004Pt-Kq for qemu-devel@nongnu.org; Wed, 07 Jun 2017 08:07:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57188) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dIZjv-0004Pg-D0 for qemu-devel@nongnu.org; Wed, 07 Jun 2017 08:07:07 -0400 Date: Wed, 7 Jun 2017 13:07:02 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170607120452.GE2384@work-vm> References: <20170606165510.33057-1-pasic@linux.vnet.ibm.com> <20170606165510.33057-4-pasic@linux.vnet.ibm.com> <20170607112252.GD2099@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [RFC PATCH 3/3] s390x/css: add hint for devno missmatch List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Halil Pasic Cc: Christian Borntraeger , "Jason J . Herne" , Juan Quintela , qemu-devel@nongnu.org * Halil Pasic (pasic@linux.vnet.ibm.com) wrote: > > > On 06/07/2017 01:22 PM, Dr. David Alan Gilbert wrote: > > * Halil Pasic (pasic@linux.vnet.ibm.com) wrote: > >> This one has to be fixed up to 's390x: vmstatify config migration for > >> virtio-ccw' provided we want to achieve the same as 's390x/css: catch > >> section mismatch on load' does. > >> > >> Signed-off-by: Halil Pasic > >> --- > >> > >> This is on tom of 's390x: vmstatify config migration for virtio-ccw' > > p > >> which ain't on top of 's390x/css: catch section mismatch on load' but on > >> top of master. I kind of have a circular dependency here. This is why > >> the series is RFC. > >> > >> Wanted to provide an usage example. Faked 'Re: ' so patchew does not > >> try to apply this on top of current master. > >> --- > >> hw/s390x/css.c | 6 +++++- > >> 1 file changed, 5 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/s390x/css.c b/hw/s390x/css.c > >> index 348129e1b2..de277d6a3d 100644 > >> --- a/hw/s390x/css.c > >> +++ b/hw/s390x/css.c > >> @@ -134,6 +134,10 @@ static const VMStateDescription vmstate_sense_id = { > >> static int subch_dev_post_load(void *opaque, int version_id); > >> static void subch_dev_pre_save(void *opaque); > >> > >> +const char err_hint_devno[] = "Devno mismatch, tried to load wrong section!" > >> + " Likely reason: some sequences of plug and unplug can break" > >> + " migration for machine versions prior to 2.7 (known design flaw)."; > >> + > > > > That's ok, but I suggest: > > * 'bug' rather than 'design flaw' - it sounds a bit less scary to > > endusers. > > > > I do not think it can be changed now. Christian as already sent out a pull > request for the patch this series is re-doing with vmstate. That patch has the > same error message. I have considered bug but decided against because > the 'bug' can't be fixed. I think it's pretty hard to hit this with normal > usage (and that's probably the reason why it went undetected until recently), > so hope not too may endusers are going to get scared by developer honesty :). No problem; it's your device anyway :-) > > Other than that, > > > > > > Reviewed-by: Dr. David Alan Gilbert > > Great thanks for the review! Dave > Halil > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK