From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753691AbbJSJnq (ORCPT ); Mon, 19 Oct 2015 05:43:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37172 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753458AbbJSJnp (ORCPT ); Mon, 19 Oct 2015 05:43:45 -0400 From: Vitaly Kuznetsov To: Olaf Hering Cc: kys@microsoft.com, haiyangz@microsoft.com, gregkh@linuxfoundation.org, devel@linuxdriverproject.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Drivers: hv: vss: run only on supported host versions References: <1444760511-4357-1-git-send-email-olaf@aepfle.de> Date: Mon, 19 Oct 2015 11:43:41 +0200 In-Reply-To: <1444760511-4357-1-git-send-email-olaf@aepfle.de> (Olaf Hering's message of "Tue, 13 Oct 2015 18:21:51 +0000") Message-ID: <87fv17xkfm.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Olaf Hering writes: > The Backup integration service on WS2012 has appearently trouble to > negotiate with a guest which does not support the provided util version. > Currently the VSS driver supports only version 5/0. A WS2012 offers only > version 1/x and 3/x, and vmbus_prep_negotiate_resp correctly returns an > empty icframe_vercnt/icmsg_vercnt. But the host ignores that and > continues to send ICMSGTYPE_NEGOTIATE messages. The result are weird > errors during boot and general misbehaviour. > > Check the Windows version to work around the host bug, skip hv_vss_init > on WS2012 and older. > > Signed-off-by: Olaf Hering > --- > drivers/hv/hv_snapshot.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c > index a548ae4..52f10ed 100644 > --- a/drivers/hv/hv_snapshot.c > +++ b/drivers/hv/hv_snapshot.c > @@ -331,6 +331,16 @@ static void vss_on_reset(void) > int > hv_vss_init(struct hv_util_service *srv) > { > + switch (vmbus_proto_version) { > + case VERSION_WS2008: > + case VERSION_WIN7: > + case VERSION_WIN8: Wouldn't it be better to simplify it to if (vmbus_proto_version < VERSION_WIN8_1) { pr_warn(); return ... } E.g. there was a patch for storvsc some time ago: commit 6ee5c61535a2df807069145970d3e7fa492a3fac Author: Keith Mange Date: Thu Aug 13 08:43:46 2015 -0700 storvsc: Rather than look for sets of specific protocol versions, make decisions based on ranges. > + pr_warn("Integration service 'Backup (volume snapshot)'" > + " not supported on this host version.\n"); > + return -ENOTSUPP; > + default: > + break; > + } > recv_buffer = srv->recv_buffer; > > /* > _______________________________________________ > devel mailing list > devel@linuxdriverproject.org > http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel -- Vitaly