From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC][PATCH 14/16] kvm: x86: Add user space part for in-kernel i8259 Date: Sun, 04 Dec 2011 16:19:24 +0100 Message-ID: <4EDB8F7C.1070602@web.de> References: <4EDB762C.7090909@redhat.com> <4EDB78DE.6000109@web.de> <4EDB7A74.4060804@redhat.com> <4EDB7ADC.50906@web.de> <4EDB7DE2.2050301@redhat.com> <4EDB7E62.7090909@web.de> <4EDB8DDE.5040402@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigC4A8C4051055F4548478D12D" Cc: Marcelo Tosatti , kvm@vger.kernel.org, qemu-devel , Anthony Liguori , "Michael S. Tsirkin" , Blue Swirl To: Avi Kivity Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:60264 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754073Ab1LDPT2 (ORCPT ); Sun, 4 Dec 2011 10:19:28 -0500 Received: from moweb002.kundenserver.de (moweb002.kundenserver.de [172.19.20.108]) by fmmailgate03.web.de (Postfix) with ESMTP id E1E721AB34590 for ; Sun, 4 Dec 2011 16:19:26 +0100 (CET) In-Reply-To: <4EDB8DDE.5040402@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigC4A8C4051055F4548478D12D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2011-12-04 16:12, Avi Kivity wrote: > On 12/04/2011 04:06 PM, Jan Kiszka wrote: >> On 2011-12-04 15:04, Avi Kivity wrote: >>> On 12/04/2011 03:51 PM, Jan Kiszka wrote: >>>>> >>>>> But the name becomes part of the save/restore ABI, so you can't. >>>> >>>> Nope, the vmstate names are identical. That would ruin migration >>>> otherwise. It's just the output of info qtree & co. that changes. >>> >>> Oh, okay. I still think it's wrong, but now it's just a matter of >>> taste, and I can live with it. >> >> Wrong in what sense? >=20 > In the sense that kernel-apic is just an accelerated apic. From the > guest point of view, there's no difference, and that should be reflecte= d > in the device model. That was my goal as well: The guest should not notice the difference, but the admin on the host side should still be able to tell both internally fairly different models apart. Plus the code should be clearly split where there are differences and explicitly shared where there aren't. >=20 > If I'm reading an apic register, either from the guest or via a monitor= > debug interface, I shouldn't care whether it's accelerated or not. The= > guest part already holds, of course. Specifically for the debug scenario, I'd prefer the clear differentiation by name as there can always remain subtle differences in the implementation of kernel vs. user space. Someone debugging the guest and/or qemu/kvm should remain aware of this. Jan --------------enigC4A8C4051055F4548478D12D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk7bj3wACgkQitSsb3rl5xQBewCdGMTgbaqmUCnRtRxJyAyb67Cx wV8AoJAHGizL/cxU/CLDbePUHazuaJKz =lwRi -----END PGP SIGNATURE----- --------------enigC4A8C4051055F4548478D12D--