From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: x86: Add instruction length to VCPU event state Date: Sat, 13 Feb 2010 11:55:38 +0100 Message-ID: <4B76852A.9040506@web.de> References: <4B76762C.10107@web.de> <4B767D3B.10306@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig1073AB0E6D51B5E616807B02" Cc: Marcelo Tosatti , kvm To: Avi Kivity Return-path: Received: from fmmailgate02.web.de ([217.72.192.227]:46380 "EHLO fmmailgate02.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248Ab0BMKzv (ORCPT ); Sat, 13 Feb 2010 05:55:51 -0500 In-Reply-To: <4B767D3B.10306@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig1073AB0E6D51B5E616807B02 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Avi Kivity wrote: > On 02/13/2010 11:51 AM, Jan Kiszka wrote: >> From: Jan Kiszka >> >> VMX requires a properly set instruction length VM entry field when >> trying to inject soft exception and interrupts. We have to preserve th= is >> state across VM save/restore to avoid breaking the re-injection of suc= h >> events on Intel. So add it to the new VCPU event state. >> >> =20 >=20 > Can't we fake it? set instruction length to 1 and rewind rip by 1. >=20 > The only case where I think this can fail is if we have a fault during > the soft exception injection. I don't think so. If e.g. privileged soft exception delivery failed, we happen to return to user space at this point and we then start a migration, we have to deal with arbitrary lengths on re-injection on the migration target. Jan --------------enig1073AB0E6D51B5E616807B02 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkt2hTIACgkQitSsb3rl5xRzVACg4C7anDSqIOqLIOh92onu1Fpr ruAAn3YoWLDb0RdQBVtheoSv1fSzeJuF =Oxzn -----END PGP SIGNATURE----- --------------enig1073AB0E6D51B5E616807B02--