From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uczi7-0001Ja-Np for qemu-devel@nongnu.org; Thu, 16 May 2013 11:03:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uczi4-0000jM-Mc for qemu-devel@nongnu.org; Thu, 16 May 2013 11:03:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55379) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uczi4-0000iy-Fb for qemu-devel@nongnu.org; Thu, 16 May 2013 11:03:12 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r4GF3BcO006272 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 16 May 2013 11:03:11 -0400 Date: Thu, 16 May 2013 18:03:26 +0300 From: "Michael S. Tsirkin" Message-ID: <20130516150326.GB2485@redhat.com> References: <1368702445-30733-1-git-send-email-akong@redhat.com> <1368702445-30733-2-git-send-email-akong@redhat.com> <20130516121745.GE31841@redhat.com> <5194F41E.3020501@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5194F41E.3020501@redhat.com> Subject: Re: [Qemu-devel] [PATCH v2 1/2] net: introduce MAC_TABLE_CHANGED event List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Amos Kong , qemu-devel@nongnu.org, stefanha@redhat.com, lcapitulino@redhat.com On Thu, May 16, 2013 at 08:58:38AM -0600, Eric Blake wrote: > On 05/16/2013 06:17 AM, Michael S. Tsirkin wrote: > > On Thu, May 16, 2013 at 07:07:24PM +0800, Amos Kong wrote: > >> Introduce this new QMP event to notify management after guest changes > >> mac-table configuration. > >> > > > > This makes it easy for guest to flood management with > > spurious events. > > How about we set a flag after this, and avoid sending any more > > events until management queries the filter status? > > > > Or use rate-limiting, similar to what we have done for other > guest-triggered events (such as BALLOON_CHANGE), where management can > then tweak the maximum frequency at which it is willing to receive events. > > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > I'm not sure how would management set the rate though, and any throttling here might hurt the guest, unlike the balloon. OTOH what I proposed kind of moderates itself automatically. -- MST