From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:32837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXJlw-0006UO-Ff for qemu-devel@nongnu.org; Sun, 04 Dec 2011 16:38:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXJlv-00053k-9N for qemu-devel@nongnu.org; Sun, 04 Dec 2011 16:38:56 -0500 Received: from fmmailgate01.web.de ([217.72.192.221]:57000) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXJlu-00053Y-UW for qemu-devel@nongnu.org; Sun, 04 Dec 2011 16:38:55 -0500 Received: from moweb001.kundenserver.de (moweb001.kundenserver.de [172.19.20.114]) by fmmailgate01.web.de (Postfix) with ESMTP id 65EB31A42980E for ; Sun, 4 Dec 2011 22:38:53 +0100 (CET) Message-ID: <4EDBE865.6000907@web.de> Date: Sun, 04 Dec 2011 22:38:45 +0100 From: Jan Kiszka MIME-Version: 1.0 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> <4EDB8F7C.1070602@web.de> <4EDBA15E.3060309@redhat.com> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigE3CCA7BA6A7AF14010DF71DA" Subject: Re: [Qemu-devel] [RFC][PATCH 14/16] kvm: x86: Add user space part for in-kernel i8259 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: Anthony Liguori , kvm@vger.kernel.org, "Michael S. Tsirkin" , Marcelo Tosatti , qemu-devel , Avi Kivity This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigE3CCA7BA6A7AF14010DF71DA Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2011-12-04 22:31, Blue Swirl wrote: > On Sun, Dec 4, 2011 at 16:35, Avi Kivity wrote: >> On 12/04/2011 05:19 PM, Jan Kiszka wrote: >>>> >>>> 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 refle= cted >>>> 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. >> >> This should be some attribute, not the name. >> >>> Plus the code should be >>> clearly split where there are differences and explicitly shared where= >>> there aren't. >> >> That's a good goal, yes. >=20 > I'd prefer an unified device built from a single source file if > possible. This conflicts with the build-once model though. Right, another reason to not do this. >=20 >>> >>>> >>>> If I'm reading an apic register, either from the guest or via a moni= tor >>>> 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 gu= est >>> and/or qemu/kvm should remain aware of this. >> >> Aware, yes, but the name change is too drastic. >=20 > It should be also possible to migrate from non-KVM device to KVM > version, different names would prevent that for ever. It is (theoretically) possible with these patches as the vmstate names are the same. KVM to TCG migration does not work right now, so I was only able to test in-kernel <-> user space irqchip model migrations. Jan --------------enigE3CCA7BA6A7AF14010DF71DA 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/ iEYEARECAAYFAk7b6GkACgkQitSsb3rl5xQdsgCgmb4qmzdYQBoweo0u/3HISfat XjkAoLXZdnuy+v4/bXETheuhU77mnWti =BDxF -----END PGP SIGNATURE----- --------------enigE3CCA7BA6A7AF14010DF71DA--