From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: KVM handling external interrupts Date: Thu, 07 Jun 2012 10:13:48 +0200 Message-ID: <4FD062BC.5090703@web.de> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig5546A4F07C157111800E662D" Cc: sheng qiu , kvm , Nadav Har'El , Alex Landau , Nadav Amit , Dan Tsafrir , Muli Ben-Yehuda To: Abel Gordon Return-path: Received: from mout.web.de ([212.227.17.11]:60163 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752351Ab2FGITS (ORCPT ); Thu, 7 Jun 2012 04:19:18 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig5546A4F07C157111800E662D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-06-07 09:51, Abel Gordon wrote: >> 3> if we configure not exit on external interrupt by setting some >> field in VMCS, what will happen during the physical interrupts? will >> the CPU use the guest IDT for response interrupt? If so, can KVM >> redirect the CPU to use another IDT for guest (assuming modifying the >> IDTR)? >=20 > Yes, that's exactly something we already did in a research project. > You can read our paper published in ASPLOS 2012: ELI: Bare-metal > performance for I/O virtualization > ( > http://dl.acm.org/citation.cfm?id=3D2151020&dl=3DACM&coll=3DDL&CFID=3D8= 6701665&CFTOKEN=3D26302003 Interesting. Can you provide it publicly (or send a version privately)? > ) >=20 > Note this is not so simple, there are many other issues you should > consider. Is it just complicated, not upstreamable, or are the unsolved issues like security holes or the need to paravirtualize the guest? I'm still hoping that Intel/AMD will finally enable this in hardware, at least for MSIs. Providing direct injection for legacy line-base interrupts is likely not worth the silicon and bits (would require some hw-assisted IOAPIC instead of just a bit more APIC virtualization). Jan --------------enig5546A4F07C157111800E662D 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/ iEYEARECAAYFAk/QYsoACgkQitSsb3rl5xSZmwCfUqcQO0r+Taedw1lQ5joeZO5l iJgAoIkPJrMFUIun9QP1Zt2zM8Ujxu7b =kiSY -----END PGP SIGNATURE----- --------------enig5546A4F07C157111800E662D--