From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47317) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dOhob-0006V9-5H for qemu-devel@nongnu.org; Sat, 24 Jun 2017 05:57:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dOhoX-0005i6-9C for qemu-devel@nongnu.org; Sat, 24 Jun 2017 05:57:17 -0400 Received: from smtp0.epfl.ch ([2001:620:618:1e0:1:80b2:e058:1]:40778) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dOhoW-0005hY-VZ for qemu-devel@nongnu.org; Sat, 24 Jun 2017 05:57:13 -0400 From: Ajallooiean Hossein Date: Sat, 24 Jun 2017 09:57:03 +0000 Message-ID: <1498298223332.65648@epfl.ch> References: <1498045580087.46004@epfl.ch>,<87injotkxi.fsf@linaro.org> In-Reply-To: <87injotkxi.fsf@linaro.org> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [Qemu-devel] Looking for ideas: Single process vs multi process qemu instances List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?iso-8859-1?Q?Alex_Benn=E9e?= Cc: "qemu-devel@nongnu.org" Hi Alex,=0A= =0A= Thanks for you email.=0A= =0A= I'm on x86-64 and am emulating ARM64 using TCG - QEMU 2.9.=0A= =0A= Well I was hoping to see if I can use a single process to have all the mach= ines within it to do a simple lockstep execution among the emulating machin= es. =0A= =0A= Im assuming the biggest issue is the thread conflicts the machines would ha= ve? other than that do you see any other obstacles?=0A= =0A= Thanks=0A= Hoss=0A= =0A= ________________________________________=0A= From: Alex Benn=E9e =0A= Sent: Thursday, June 22, 2017 11:45 AM=0A= To: Ajallooiean Hossein=0A= Cc: qemu-devel@nongnu.org=0A= Subject: Re: [Qemu-devel] Looking for ideas: Single process vs multi proces= s qemu instances=0A= =0A= Ajallooiean Hossein writes:=0A= =0A= > Hi All,=0A= >=0A= >=0A= > we are trying to do server simulation and for that purpose we need to=0A= > have multiple Qemu instances (each can have a different spec) that are=0A= > part of a virtual network (ns-3 in our case).=0A= =0A= So you are talking about using TCG for simulation rather than KVM here?=0A= =0A= >=0A= >=0A= > Now for the Qemu implementation part: would it be easier/better to=0A= > have all the Qemu instances under a single process or multiple=0A= > processes? i am assuming if one single process is used, there will be=0A= > a threading conflict that would probably need to be looked at.=0A= =0A= QEMU isn't really setup for multiple machine instances in the one=0A= binary. If you are simulating a complex set of communicating machines=0A= then you will need one QEMU instance per machine.=0A= =0A= TCG can now use multiple threads (one per emulated vCPU) but this has=0A= only been enabled for a subset of architectures so far. You don't say=0A= what architecture your servers machines are.=0A= =0A= >=0A= >=0A= > I am looking at this purely from a management/performance view.=0A= >=0A= >=0A= > Any ideas/suggestions?=0A= >=0A= >=0A= > Thanks=0A= >=0A= > Hoss=0A= =0A= =0A= --=0A= Alex Benn=E9e=0A=