From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Magenheimer <dan.magenheimer@oracle.com>
Subject: RE: [PATCH 01/02] pvrdtscp: move the place of
	write_rdtscp_aux()
Date: Fri, 11 Dec 2009 08:14:21 -0800 (PST)
Message-ID: <5d279b8a-e744-4677-9ca9-167aad52ab5b@default>
References: <EADF0A36011179459010BDF5142A457501D13FE81F@pdsmsx502.ccr.corp.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=Windows-1252
Content-Transfer-Encoding: quoted-printable
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <EADF0A36011179459010BDF5142A457501D13FE81F@pdsmsx502.ccr.corp.intel.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: "Xu, Dongxiao" <dongxiao.xu@intel.com>, xen-devel@lists.xensource.com
Cc: Keir Fraser <keir.fraser@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

I am OK with this patch [01/02] now (see other thread),
though still would like the discussion to continue
about the other patch [02/02].

Thanks,
Dan

> -----Original Message-----
> From: Xu, Dongxiao [mailto:dongxiao.xu@intel.com]
> Sent: Friday, December 11, 2009 8:31 AM
> To: Dan Magenheimer; xen-devel@lists.xensource.com
> Cc: Keir Fraser
> Subject: RE: [Xen-devel][PATCH 01/02] pvrdtscp: move the place of
> write_rdtscp_aux()
>=20
>=20
> Dan Magenheimer wrote:
> > This patch is wrong for TSC_MODE_PVRDTSCP.  The original
> > code should be left in __update_vcpu_system_time and
> > the context switch code should write to TSC_AUX only
> > if tsc_mode is *NOT* TSC_MODE_PVRDTSCP because the
> > implementation of full rdtscp functionality and
> > TSC_MODE_PVRDTSCP mode are incompatible.
>=20
> Could you detail the wrong place? Appreciate for this!
> In my patch, I have done save/restore for guest/host=20
> TSC_AUX MSR, so it will not break PVRDTSC logic.=20
> =20
> >=20
> > But I continue to question if this should be done at all.
> > See other thread.
> >=20
> >> -----Original Message-----
> >> From: Xu, Dongxiao [mailto:dongxiao.xu@intel.com]
> >> Sent: Friday, December 11, 2009 4:54 AM
> >> To: xen-devel@lists.xensource.com
> >> Cc: Keir Fraser
> >> Subject: [Xen-devel][PATCH 01/02] pvrdtscp: move the place of
> >> write_rdtscp_aux()=20
> >>=20
> >>=20
> >>  Pvrdtscp: move write_rdtscp_aux() to paravirt_ctxt_switch_to()
> >>  - Currently write_rdtscp_aux() is placed in
> >> update_vcpu_system_time(), which
> >> is called by schedule() before context_switch(). This will
> >> break the HVM guest
> >> TSC_AUX state because at this point, MSR hasn't beed saved
> >> for HVM guests.So
> >> put the function in the point when a PV vcpu is really=20
> scheduled in.
> >>=20
> >> Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>