From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40886) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eR6OB-0002Ze-0z for qemu-devel@nongnu.org; Mon, 18 Dec 2017 20:08:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eR6O7-00081U-O2 for qemu-devel@nongnu.org; Mon, 18 Dec 2017 20:08:10 -0500 Date: Tue, 19 Dec 2017 11:37:03 +1100 From: David Gibson Message-ID: <20171219003703.GF4786@umbus.fritz.box> References: <20171218092024.21645-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SxgehGEc6vB0cZwN" Content-Disposition: inline In-Reply-To: <20171218092024.21645-1-david@gibson.dropbear.id.au> Subject: Re: [Qemu-devel] [PATCH 0/6] spapr: Add optional capabilities List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: surajjs@au1.ibm.com, groug@kaod.org, lvivier@redhat.com Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, abologna@redhat.com --SxgehGEc6vB0cZwN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 18, 2017 at 08:20:18PM +1100, David Gibson wrote: > This series is a first draft to add the notion of optional > capabilities to the "pseries" machine type. A default set of > capabilities is selected based on the machine type version and > selected cpu model, but this can be overridden with machine > parameters. >=20 > The purpose of this is to get rid of a number of places where we > implicitly decide what features to advertise to the guest based on > capabilities of the host. This is bad, because it means it's > difficult to be certain if machines started at different ends of a > migration really match from the guest's point of view. >=20 > By giving the user explicit control of these optional features, then > validating that the chosen ones can be supplied on the host we make > behaviour more predictable. >=20 > The more specific motivation for this is that POWER9 has bugs in its > hardware transactional memory (HTM) implementation making it unsafe to > migrate POWER8 guests to POWER9 if they use HTM. I've fixed the user-after-free bug Greg pointed out and merged this into ppc-for-2.12. --=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 --SxgehGEc6vB0cZwN Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAlo4Xy8ACgkQbDjKyiDZ s5LIsxAA0bKDvnqA2M4OGTR0RHfMGCLxGbI7NQpPAhd8JdDq6ds2RC0jDwZOPLtF pDFgf72WgSD3rXnLNuV2CUzRmHlokr+kzxMjzpGh12yPrOxjSsc3El75n7zAQAk7 4dtoC8SzCAz6fNfAh0vIe57eY5LlceY9N+X3Q2EBG3mDtNJSCLpK7abgN0ycujIN fDOJvLJq3MHe1G+dBvy795dPNEGthZBOeg3eV2d1aI3XZWl7gya4wOIxUmzu0PK/ isU5vnX+RVPcqMnl+vpXli9C0lBb73fZStlIKeZBzjp0j0tqf6I+Aai8Qv11b5Gv P33sxKtDlQHESIpmATpk5RAC4ajKxEZovi9PQYw93KmndePYJn0+r7ZfzqpktHaB izKVk5jaZOzqd6Fg+LWUOZb3fcpSAmD0iVDTlrvErBrrFzfnt0ZN3bC+WC2qP96y iqp4Pu0xr4xR7peBB0lBjcmwf8q+lDAgbrUy0kdotmvSxTzWXAcwptmgXZ8vdEWf KSasVEk041MgtiDX5aySl1pf1zpsuWmKOLg755m9M4JSRm/W+Wa3KDauSKt+41LP NzUFLsLAB7bKKPCP05IjPLAGIBJjhq4mFk52AeaLlEFIqGx3juL9mx/j2lWL8gsV j3rsmJhem1OI6IlH5CN+sugqrAR1lId4m8FrWP6egzbtX/SzOkI= =TKn7 -----END PGP SIGNATURE----- --SxgehGEc6vB0cZwN--