From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56443) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fOidh-0000pk-FU for qemu-devel@nongnu.org; Fri, 01 Jun 2018 07:54:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fOidc-0007Vb-Na for qemu-devel@nongnu.org; Fri, 01 Jun 2018 07:54:37 -0400 Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]:55034) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fOidc-0007Tg-FP for qemu-devel@nongnu.org; Fri, 01 Jun 2018 07:54:32 -0400 Received: by mail-wm0-x241.google.com with SMTP id o13-v6so2514834wmf.4 for ; Fri, 01 Jun 2018 04:54:32 -0700 (PDT) Date: Fri, 1 Jun 2018 12:54:29 +0100 From: Stefan Hajnoczi Message-ID: <20180601115429.GL8687@stefanha-x1.localdomain> References: <20180523140809.622F.E1E9C6FF@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2EnvhqpWJq810sZn" Content-Disposition: inline In-Reply-To: <20180523140809.622F.E1E9C6FF@jp.fujitsu.com> Subject: Re: [Qemu-devel] Questions about vNVDIMM on qemu/KVM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yasunori Goto Cc: qemu-devel@nongnu.org, NVDIMM-ML , Pankaj Gupta , Luiz Capitulino --2EnvhqpWJq810sZn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 23, 2018 at 02:08:12PM +0900, Yasunori Goto wrote: > Hello, CCing Pankaj, who is developing virtio-pmem and may have comments beyond what has already been discussed. > I'm investigating status of vNVDIMM on qemu/KVM, > and I have some questions about it. I'm glad if anyone answer them. >=20 > In my understanding, qemu/KVM has a feature to show NFIT for guest, > and it will be still updated about platform capability with this patch se= t. > https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg04756.html >=20 > And libvirt also supports this feature with > https://libvirt.org/formatdomain.html#elementsMemory >=20 >=20 > However, virtio-pmem is developing now, and it is better > for archtectures to detect regions of NVDIMM without ACPI (like s390x) > In addition, It is also necessary to flush guest contents on vNVDIMM > who has a backend-file.=20 >=20 >=20 > Q1) Does ACPI.NFIT bus of qemu/kvm remain with virtio-pmem?=20 > How do each roles become it if both NFIT and virtio-pmem will be avai= lable? > If my understanding is correct, both NFIT and virtio-pmem is used to > detect vNVDIMM regions, but only one seems to be necessary.... >=20 > Otherwize, is the NFIT bus just for keeping compatibility,=20 > and virtio-pmem is promising way? >=20 > =20 > Q2) What bus is(will be?) created for virtio-pmem? > I could confirm the bus of NFIT is created with , > and I heard other bus will be created for virtio-pmem, but I could not > find what bus is created concretely. > --- > # ndctl list -B > { > "provider":"ACPI.NFIT", > "dev":"ndbus0" > } > --- > =20 > I think it affects what operations user will be able to, and what=20 > notification is necessary for vNVDIMM.=20 > ACPI defines some operations like namespace controll, and notification > for NVDIMM health status or others. > (I suppose that other status notification might be necessary for vNVD= IMM, > but I'm not sure yet...) >=20 > If my understanding is wrong, please correct me. >=20 > Thanks, > --- > Yasunori Goto >=20 >=20 >=20 --2EnvhqpWJq810sZn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJbETP1AAoJEJykq7OBq3PIAToH/0iQQq1xrjtmm9Pei8pYlY+X nyA9L2Q4VhEla9wurFPtksJrKq8aDjou/JwaciD4LNqKWBXR0WNp5j7HNDFe6Jez 4Kax0uUrCra7PKnFr4fK6EZq7JJF/3gT+Pkr0r2Q/hBLCGYgeMjVN2fnIV3Hyl3p ZeKfluimW/8rfCsZxqorRRcZCo6//pJtnTx+HEbmThD5RIeFtAN7yK1rNzWMMWYr Ncmb69ktN0CC2kn7pCF5VfjaSrM1MUFcpUXTGU5ENE5pQ+ox0gggh38jSmVm1XUu 24gDBZxnm3QIVGiYOVFisalpxDlkGcIAJA0OhGbI38hzkTLiEbCBl0zyf5IUB3c= =xGxs -----END PGP SIGNATURE----- --2EnvhqpWJq810sZn--