From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:46285) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QygKF-0000BV-5R for qemu-devel@nongnu.org; Wed, 31 Aug 2011 04:39:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QygKE-0001Rq-3C for qemu-devel@nongnu.org; Wed, 31 Aug 2011 04:39:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18628) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QygKD-0001RV-SI for qemu-devel@nongnu.org; Wed, 31 Aug 2011 04:39:10 -0400 Message-ID: <4E5DF31A.1@redhat.com> Date: Wed, 31 Aug 2011 11:38:50 +0300 From: Avi Kivity MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH, RFC] trace: implement guest tracepoint passthrough List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: =?ISO-8859-1?Q?Llu=EDs?= , Dhaval Giani , Stefan Hajnoczi , qemu-devel On 08/26/2011 10:06 PM, Blue Swirl wrote: > Let guests inject tracepoint data via fw_cfg device. > > At least on x86, fw_cfg is pretty slow, involving multiple exits. IMO, for kvm, even one exit per tracepoint is too high. We need to use a shared memory transport with a way to order guest/host events later on (by using a clock). -- error compiling committee.c: too many arguments to function