From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43805) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xlgkk-0005X1-QN for qemu-devel@nongnu.org; Tue, 04 Nov 2014 11:14:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XlgkZ-0004CB-9H for qemu-devel@nongnu.org; Tue, 04 Nov 2014 11:14:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33263) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XlgkY-0004C3-P7 for qemu-devel@nongnu.org; Tue, 04 Nov 2014 11:14:31 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sA4GEUHA026068 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 4 Nov 2014 11:14:30 -0500 Date: Tue, 4 Nov 2014 17:14:29 +0100 From: Igor Mammedov Message-ID: <20141104171429.13ed86c0@nial.usersys.redhat.com> In-Reply-To: <5458F3DF.4040003@redhat.com> References: <1414773522-7756-1-git-send-email-imammedo@redhat.com> <1414773522-7756-4-git-send-email-imammedo@redhat.com> <54576C56.9040704@redhat.com> <20141103180013.5b4e2831@igors-macbook-pro.local> <5457BC43.5020403@redhat.com> <20141103201110.2bf16a05@igors-macbook-pro.local> <5458921B.3000807@redhat.com> <20141104163905.35866f63@nial.usersys.redhat.com> <5458F3DF.4040003@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 03/11] pc: check if KVM has enough memory slots for DIMM devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, mst@redhat.com On Tue, 04 Nov 2014 16:42:23 +0100 Paolo Bonzini wrote: > > > On 04/11/2014 16:39, Igor Mammedov wrote: > >> > But he cannot even with your patch, if he was off by just a couple > >> > items. So I don't think the improvement is worth the extra complication > >> > of the code and the small layering violation. > > With this patch user can launch QEMU with exact max amount of possible > > slots with exception that he won't hotplug other than pc-dimm devices > > that consume KVM's memory slots (not sure if such exists (hotpluggable)). > > but, sure we can drop this patch until someone complains. > > Note that option ROM BARs (which are usually mapped only by firmware, > but also when accessed via sysfs) and device assignment both consume > memory slots. Slots occupied by pflash can also come and go, depending > on whether the flash is visible as ROM or in programming mode. Then there is a bigger problem, once KVM slots are saturated QEMU will crash if one of above actions from guest happens, and we can't even error out on them. > > Paolo >