From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH v3 07/10] qemu-kvm: Cleanup/fix TSC and PV clock writeback Date: Thu, 25 Feb 2010 00:45:55 +0100 Message-ID: <4B85BA33.5080008@web.de> References: <20100224231708.GB16246@amt.cnet> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig09D5711233FA48885C0D9B71" Cc: Avi Kivity , kvm@vger.kernel.org, qemu-devel@nongnu.org, Gleb Natapov , Zachary Amsden To: Marcelo Tosatti Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:60937 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758420Ab0BXXqB (ORCPT ); Wed, 24 Feb 2010 18:46:01 -0500 In-Reply-To: <20100224231708.GB16246@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig09D5711233FA48885C0D9B71 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Marcelo Tosatti wrote: > On Wed, Feb 24, 2010 at 03:17:55PM +0100, Jan Kiszka wrote: >> Drop kvm_load_tsc in favor of level-dependent writeback in >> kvm_arch_load_regs. KVM's PV clock MSRs fall in the same category and >> should therefore only be written back on full sync. >> >> Signed-off-by: Jan Kiszka >> --- >> qemu-kvm-x86.c | 19 +++++-------------- >> qemu-kvm.h | 4 ---- >> target-i386/machine.c | 5 ----- >> 3 files changed, 5 insertions(+), 23 deletions(-) >> >> diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c >> index 840c1c9..84fd7fa 100644 >> --- a/qemu-kvm-x86.c >> +++ b/qemu-kvm-x86.c >> @@ -965,8 +965,11 @@ void kvm_arch_load_regs(CPUState *env, int level)= >> set_msr_entry(&msrs[n++], MSR_LSTAR , env->lstar);= >> } >> #endif >> - set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_= msr); >> - set_msr_entry(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_ms= r); >> + if (level =3D=3D KVM_PUT_FULL_STATE) { >> + set_msr_entry(&msrs[n++], MSR_IA32_TSC, env->tsc); >> + set_msr_entry(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_ti= me_msr); >> + set_msr_entry(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock= _msr); >> + } >=20 > As things stand today, the TSC should only be written on migration. See= > 53f658b3c33616a4997ee254311b335e59063289 in the kernel. Migration and power-up - that's what this patch ensures (=3D> KVM_PUT_FULL_STATE). Or where do you see any problem? Jan --------------enig09D5711233FA48885C0D9B71 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 iEYEARECAAYFAkuFujgACgkQitSsb3rl5xTOlACgwSdbOJNcQvbsZZQlEV/qCPLv DBkAoO54syarouUc6xdQpj3lN1Vf9PKt =6UqR -----END PGP SIGNATURE----- --------------enig09D5711233FA48885C0D9B71--