From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 5/5] HPET interaction with in-kernel PIT (v6) Date: Sun, 14 Jun 2009 11:10:42 +0200 Message-ID: <4A34BE92.6010302@web.de> References: <1244771206-19872-1-git-send-email-eak@us.ibm.com> <1244771206-19872-5-git-send-email-eak@us.ibm.com> <4A34BA88.7060204@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig0FF8076EAC08CE60FC2CAF26" Cc: kvm@vger.kernel.org To: Avi Kivity , Beth Kon Return-path: Received: from fmmailgate02.web.de ([217.72.192.227]:48335 "EHLO fmmailgate02.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752309AbZFNJKs (ORCPT ); Sun, 14 Jun 2009 05:10:48 -0400 In-Reply-To: <4A34BA88.7060204@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig0FF8076EAC08CE60FC2CAF26 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Avi Kivity wrote: > Beth Kon wrote: >> Signed-off-by: Beth Kon >> >> =20 >=20 > Please write a few words on what this patch does and why. >=20 >> --- >> arch/x86/include/asm/kvm.h | 1 + >> arch/x86/kvm/i8254.c | 24 +++++++++++++++++++----- >> arch/x86/kvm/i8254.h | 3 ++- >> arch/x86/kvm/x86.c | 5 ++++- >> 4 files changed, 26 insertions(+), 7 deletions(-) >> >> diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h >> index 708b9c3..3c44923 100644 >> --- a/arch/x86/include/asm/kvm.h >> +++ b/arch/x86/include/asm/kvm.h >> @@ -235,6 +235,7 @@ struct kvm_guest_debug_arch { >> =20 >> struct kvm_pit_state { >> struct kvm_pit_channel_state channels[3]; >> + u8 hpet_legacy_mode; >> }; >> =20 >=20 > This changes the ABI, breaking older binaries running on newer kernels,= > or newer binaries running on older kernels. As we have KVM_CREATE_PIT2 now, which includes struct kvm_pit_config with a lot of unused flags, it should be straightforward to negotiate the kvm_pit_state format between kernel and user space: kernel advertises support for the new one via capability, user space requests it via a bit in kvm_pit_state.flags. Jan --------------enig0FF8076EAC08CE60FC2CAF26 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 iEYEARECAAYFAko0vpUACgkQniDOoMHTA+kScACeOX7ldGALlRmNq2hUo/si30Bv 6hYAniRIUtRsqDsK7fKR2PmTMeqPd43U =1464 -----END PGP SIGNATURE----- --------------enig0FF8076EAC08CE60FC2CAF26--