From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39055) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZAuA4-0006ds-Tg for qemu-devel@nongnu.org; Fri, 03 Jul 2015 02:09:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZAuA0-0006l9-9v for qemu-devel@nongnu.org; Fri, 03 Jul 2015 02:09:20 -0400 Date: Fri, 3 Jul 2015 16:01:02 +1000 From: David Gibson Message-ID: <20150703060102.GB16378@voom.redhat.com> References: <20141105071019.26196.93729.stgit@aravindap> <20141111032421.GH15270@voom.redhat.com> <546C2F4A.5010708@linux.vnet.ibm.com> <551CC55B.3050901@ozlabs.ru> <20150402044625.GA25823@voom.redhat.com> <55950058.8040508@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="aVD9QWMuhilNxW9f" Content-Disposition: inline In-Reply-To: <55950058.8040508@ozlabs.ru> Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/4] target-ppc: Add FWNMI support in qemu for powerKVM guests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: benh@au1.ibm.com, aik@au1.ibm.com, Alexander Graf , qemu-devel@nongnu.org, qemu-ppc@nongnu.org, Aravinda Prasad , paulus@samba.org --aVD9QWMuhilNxW9f Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 02, 2015 at 07:11:52PM +1000, Alexey Kardashevskiy wrote: > On 04/02/2015 03:46 PM, David Gibson wrote: > >On Thu, Apr 02, 2015 at 03:28:11PM +1100, Alexey Kardashevskiy wrote: > >>On 11/19/2014 04:48 PM, Aravinda Prasad wrote: > >>> > >>> > >>>On Tuesday 11 November 2014 08:54 AM, David Gibson wrote: > >>> > >>>[..] > >>> > >>>> > >>>>So, this may not still be possible depending on whether the KVM side > >>>>of this is already merged, but it occurs to me that there's a simpler > >>>>way. > >>>> > >>>>Rather than mucking about with having to update the hypervisor on the > >>>>RTAS location, they have qemu copy the code out of RTAS, patch it and > >>>>copy it back into the vector, you could instead do this: > >>>> > >>>> 1. Make KVM instead of immediately delivering a 0x200 for a guest > >>>>machine check, cause a special exit to qemu. > >>>> > >>>> 2. Have the register-nmi RTAS call store the guest side MC handler > >>>>address in the spapr structure, but perform no actual guest code > >>>>patching. > >>>> > >>>> 3. Allocate the error log buffer independently from the RTAS blob, > >>>>so qemu always knows where it is. > >>>> > >>>> 4. When qemu gets the MC exit condition, instead of going via a > >>>>patched 0x200 vector, just directly set the guest register state and > >>>>jump straight into the guest side MC handler. > >>>> > >>> > >>>Before I proceed further I would like to know what others think about > >>>the approach proposed above (except for step 3 - as per PAPR the error > >>>log buffer should be part of RTAS blob and hence we cannot have error > >>>log buffer independent of RTAS blob). > >>> > >>>Alex, Alexey, Ben: Any thoughts? > >> > >> > >>Any updates about FWNMI? Thanks > > > >Huh.. I'd completely forgotten about this. Aravinda, can you repost > >your latest work on this? >=20 >=20 > Aravinda disappeared... Ok, well someone who cares about FWNMI is going to have to start sending something, or it won't happen. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --aVD9QWMuhilNxW9f Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVliUdAAoJEGw4ysog2bOSc2AP/iZDqVqzxemm0ZUOFNelz/ag qLRc7lHm2vY+gJ1X8AcXWi5pfeypKwXYAPOsribb+W4RQBePqln01pWq1UDy0V+8 VBpFacOTqVnzjRAp9rjE7PgkAZJu79mRM+pA60coyd5L84X/Sr7FgZo6MLj3i+IA SfwD5vXTdGye5Wg6/Hu2oQTnO+SVfM1+W+vZqKHzz1e6RhQBNJesNLiP91FSBBBl euA5ag/tnsAJvwVWhCt/y/8Crl1vfw8Le7CCQE1mbJ5ZAXnDW4DaCkxejS0i0NZI SL0/ZdwrtZUCd6FTm3fdqoEGoSkOk2cWBmSGEW+zxjQG94LQQNkb/o8RlwPjAcft RiLRMOW2YWu4lM7qe/oOXTlv/ACsSMiEETmGjEB9OZ3e9LpTWY5WpTKlvZBiQ8Cz zNUqnJmQHtrH4O9Mfgsk+FwMSsYjmB1rpgPCNOg2nyn2LZxcAqDE8CSWViRxlkcz EXhkVfhevYkWA0xFXvNtGbd870CZG+vArGsOuy8zPvfMQd55mBmtd8hPbc5SS4yL 8oxYKMGmAo2iZxl2xF5UwzNivNlj9UMVFDgghZnbg4J5e2NsBVWa45TFvi4QQpoS QM8UjDlSdVyOv4hnGRB5P7SBKVHLEcdNJi9ijf9cbcDh82P3uGL54+4DFGC/QiSW jZtKuIW2cVPgzxmqB7CR =vcgV -----END PGP SIGNATURE----- --aVD9QWMuhilNxW9f--