From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57603) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1k2v-0005u4-Br for qemu-devel@nongnu.org; Mon, 30 Jun 2014 18:27:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X1k2n-0006mR-Gg for qemu-devel@nongnu.org; Mon, 30 Jun 2014 18:27:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2394) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1k2n-0006mJ-6s for qemu-devel@nongnu.org; Mon, 30 Jun 2014 18:27:25 -0400 Message-ID: <53B1E449.9000303@redhat.com> Date: Mon, 30 Jun 2014 16:27:21 -0600 From: Eric Blake MIME-Version: 1.0 References: In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="epgB2D0Xbhfqb9JbJB5ip378rRerpXvCv" Subject: Re: [Qemu-devel] Qemu Shared memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gary Jordan , qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --epgB2D0Xbhfqb9JbJB5ip378rRerpXvCv Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 06/30/2014 10:34 AM, Gary Jordan wrote: > Dear developers, >=20 > I want to design a shared memory for Vm in qemu. So, I also need to des= ign > a mechanism to let two vms communicate. Is there already some module in= > Qemu ? It sounds like you are asking about ivshmem, which has already been discussed a lot lately. Please search the list archives. >=20 > I saw that qemu could support live migration. Can the vm also access th= e > previous machine after migration? Thanks. I'm not sure what you are asking here. From the guest's standpoint, live migration is transparent (the guest should not know that it was migrated). Migration is probably unrelated to intra-vm communication, other than the fact that if you use shared memory to do intra-vm communication, you have probably rendered your guest unmigrateable. How would you communicate between two bare-metal hosts? The best design is one in which your guests use the same (emulated) hardware for intercommunication. So, if two hosts can effectively communicate via a network, then using a virtio-net network to communicate between two guests is the ideal emulation, and also avoids anti-migration lock-in that you might get if you instead opt for shared memory solutions such as ivshmem. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --epgB2D0Xbhfqb9JbJB5ip378rRerpXvCv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJTseRJAAoJEKeha0olJ0NqL6oH/RNRwh2MacfaiQZ5884Uazqw OsYDHDkj57CGmAyniArYs0TtUXadOa4CCknPSNiHouBIDzSOUc84g26H7fNKxBLO TGOitvRkyifT5H6SA9U7hIVnOdSV88bhlL2J8xDrAd/yb3ZVBLqxsv8f3RWJ1Sih BQyDoHZFxlpGXSMsNNd4lBB07azd4xAVWgEAps++ZZDW9PZ51Yo6lmDXYtQ0rKH7 LoLHq8pG/2Au1340z3qttXshpRwOJ0ORlEoQ4mM9w+5dCFf/aPvTO0cKVfSmdQNf W616m6jtZa2WlW+qvq6ug9fqHg4oZtR7+d9TJ7oCMtn+mqsL8j+4qGfs0q/5rCo= =hvFz -----END PGP SIGNATURE----- --epgB2D0Xbhfqb9JbJB5ip378rRerpXvCv--