From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: KVM handling external interrupts Date: Thu, 07 Jun 2012 12:23:15 +0200 Message-ID: <4FD08113.9080709@web.de> References: <4FD062BC.5090703@web.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig5E3A8C5E7C075589CCE31CAC" Cc: Alex Landau , Dan Tsafrir , sheng qiu , kvm , Muli Ben-Yehuda , Nadav Har'El , Nadav Amit To: Abel Gordon Return-path: Received: from mout.web.de ([212.227.17.12]:59918 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757853Ab2FGKXX (ORCPT ); Thu, 7 Jun 2012 06:23:23 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig5E3A8C5E7C075589CCE31CAC Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-06-07 11:55, Abel Gordon wrote: >=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? >=20 > Well, I let you read the paper first :) It will answer all these questi= ons. I'm on it. Two general remarks so far: - At least the preemption timer is not common x86 architecture but can only be found in VT-x. You should mention that you are focusing on Intel. - You discuss interrupt delivery without stating that you have MSIs in mind. Some aspects may be helpful for legacy interrupts as well, but you obviously can't achieve exit-less operation there. Not an issue, should just be made clear. >=20 > In a nutshell, > Complicated: that always depends who you ask and relative to what you > consider something complicated. ELI changes some critical points in KVM= =2E > Unsolved issues: there are some issues solves in theory but not impleme= nted > Security holes: not if you are OK with the threat model we describe in = the > paper The thread model looks sane, but I'm not feeling well with the "let's poll the guest to see if it misbehaved" solution. It should work but is a bit ugly. > need paravirtualize the guest: no if you have x2APIC. =2E..and the guest makes use of it. This excludes older OSes. When did Windows start to use it? Jan --------------enig5E3A8C5E7C075589CCE31CAC 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/QgRcACgkQitSsb3rl5xQQcwCgp+W/FF4wjvrdtYYjFSYRFoUr CaQAn1tD4gKouN1RKLm2k/v4i789dsx4 =UT79 -----END PGP SIGNATURE----- --------------enig5E3A8C5E7C075589CCE31CAC--