From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: Re: [Qemu-devel] [RFC] qemu: Add virtio pmem device Date: Mon, 9 Apr 2018 11:26:01 +0800 Message-ID: <20180409032601.GA1648@stefanha-x1.localdomain> References: <20180405104834.10457-1-pagupta@redhat.com> <20180405104834.10457-4-pagupta@redhat.com> <416823501.16310251.1522930166070.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cWoXeonUoKmBZSoM" Return-path: Content-Disposition: inline In-Reply-To: <416823501.16310251.1522930166070.JavaMail.zimbra@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Pankaj Gupta Cc: David Hildenbrand , kwolf@redhat.com, haozhong zhang , jack@suse.cz, xiaoguangrong eric , kvm@vger.kernel.org, riel@surriel.com, linux-nvdimm@ml01.01.org, mst@redhat.com, ross zwisler , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, hch@infradead.org, pbonzini@redhat.com, stefanha@redhat.com, niteshnarayanlal@hotmail.com, marcel@redhat.com, imammedo@redhat.com, dan j williams , nilal@redhat.com List-Id: linux-nvdimm@lists.01.org --cWoXeonUoKmBZSoM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 05, 2018 at 08:09:26AM -0400, Pankaj Gupta wrote: > > Will this raw file already have the "disk information header" (no idea > > how that stuff is called) encoded? Are there any plans/possible ways to > >=20 > > a) automatically create the headers? (if that's even possible) >=20 > Its raw. Right now we are just supporting raw format. =20 >=20 > As this is direct mapping of memory into guest address space, I don't > think we can have an abstraction of headers for block specific features. > Or may be we can get opinion of others(Qemu block people) it is at all po= ssible? memdev and the block layer are completely separate. The block layer isn't designed for memory-mapped access. I think it makes sense to use memdev here. If the user wants a block device, they should use an emulated block device, not virtio-pmem, because buffering is necessary anyway when an image file format is used. Stefan --cWoXeonUoKmBZSoM Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJayt1JAAoJEJykq7OBq3PI+GkH/1E+ci/o0GU4EORh4j1KOyFX JtWmDNcdJfKLdUonRX6ZCns34at7dTNf0U6nFlqzDB5bkMdh3H8Tid/8u57Q9MdI Y2e1Xr/IxugahIok4g5c9bN43zNWnKzGF+G/OMuCDe76oLpAm9GccKl/M2EaiXo3 rLACtHLAv+t8FNmFHw4BTz2Nt5zW6D3YiAj/M/wdk9N/z/QnbN4glWWbI8ukmNMc +e7n/yZH4TmJikN6BAvRvCrT4EemU9LpXloM5z5qXGJkJaNn+9ZQQCjwaJXdyOKt OTKLvVMdOt3x+0JxnSnisMkPtmIJtuHJY0bmjYfnrn9fh1blM9SQ8Q3nXVHQv9E= =9Dfp -----END PGP SIGNATURE----- --cWoXeonUoKmBZSoM--