Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Michael Kelley <mikelley@microsoft.com>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Sasha Levin <sashal@kernel.org>
CC:     Vincenzo Frascino <vincenzo.frascino@arm.com>,
        "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
        "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Russell King <linux@armlinux.org.uk>,
        Ralf Baechle <ralf@linux-mips.org>,
        Paul Burton <paul.burton@mips.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Mark Salyzyn <salyzyn@android.com>,
        Peter Collingbourne <pcc@google.com>,
        Shuah Khan <shuah@kernel.org>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Huw Davies <huw@codeweavers.com>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>
Subject: RE: [PATCH v6 18/19] x86: Add support for generic vDSO
Thread-Topic: [PATCH v6 18/19] x86: Add support for generic vDSO
Thread-Index: AQHVFvJX/FWqgsMYXUWDuWvrdwhvDKaDyyHwgBdL5YCAAKgjAIAMJX0AgAHb0oCAADMqgIAAGq6A
Date:   Mon, 24 Jun 2019 00:04:06 +0000
Message-ID: <BYAPR21MB135202F46C4B023B51EBBFD0D7E00@BYAPR21MB1352.namprd21.prod.outlook.com>
References: <20190530141531.43462-1-vincenzo.frascino@arm.com>
 <20190530141531.43462-19-vincenzo.frascino@arm.com>
 <BYAPR21MB1221D54FCEC97509EEF7395CD7180@BYAPR21MB1221.namprd21.prod.outlook.com>
 <alpine.DEB.2.21.1906141313150.1722@nanos.tec.linutronix.de>
 <20190614211710.GQ1513@sasha-vm>
 <alpine.DEB.2.21.1906221542270.5503@nanos.tec.linutronix.de>
 <20190623190929.GL2226@sasha-vm>
 <alpine.DEB.2.21.1906240006090.32342@nanos.tec.linutronix.de>
In-Reply-To: <alpine.DEB.2.21.1906240006090.32342@nanos.tec.linutronix.de>
Accept-Language: en-US
Content-Language: en-US
msip_labels: MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Enabled=True;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SiteId=72f988bf-86f1-41af-91ab-2d7cd011db47;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Owner=mikelley@ntdev.microsoft.com;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SetDate=2019-06-24T00:04:04.8777887Z;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Name=General;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Application=Microsoft Azure
 Information Protection;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ActionId=e048b72d-2ff1-4f2d-bcd5-a23a499f2ba1;
 MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Extended_MSFT_Method=Automatic
authentication-results: spf=none (sender IP is )
 smtp.mailfrom=mikelley@microsoft.com; 
x-originating-ip: [24.22.167.197]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: 4dbb63a6-0779-43fa-f69c-08d6f83779cc
x-ms-office365-filtering-ht: Tenant
x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(4618075)(2017052603328)(7193020);SRVR:BYAPR21MB1301;
x-ms-traffictypediagnostic: BYAPR21MB1301:
x-microsoft-antispam-prvs: <BYAPR21MB1301C5BD6394A1921BD73681D7E00@BYAPR21MB1301.namprd21.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:8882;
x-forefront-prvs: 007814487B
x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(376002)(136003)(366004)(39860400002)(346002)(396003)(54534003)(199004)(189003)(76116006)(3846002)(305945005)(7736002)(10290500003)(55016002)(5660300002)(478600001)(486006)(73956011)(6436002)(81156014)(53936002)(52536014)(8676002)(25786009)(11346002)(66476007)(71200400001)(71190400001)(66556008)(64756008)(66446008)(33656002)(66946007)(6116002)(186003)(229853002)(81166006)(446003)(476003)(8936002)(256004)(8990500004)(7696005)(10090500001)(6246003)(74316002)(102836004)(7416002)(4326008)(9686003)(99286004)(26005)(76176011)(68736007)(316002)(22452003)(54906003)(110136005)(2906002)(14454004)(86362001)(66066001)(6506007)(41533002);DIR:OUT;SFP:1102;SCL:1;SRVR:BYAPR21MB1301;H:BYAPR21MB1352.namprd21.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1;
received-spf: None (protection.outlook.com: microsoft.com does not designate
 permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: NssyykIjQ9mRtBfcrKUSGwo+J2+usrM0gyLhCizMFEI0GK9jzfMgcyGOvMrAFOjc8WlvHQRndRleFierKlODV6tRz8kShtZf9+xjBBWbvX31il1byFxCIxl2jG/5eWed/5U5rA6eCf/LyR3FNTQwZJgiBcGL6IVkHRsjk3fN3Q7Zqox6w8JAhfDxMNlrsl/BJVE8XTrXPsRsHNg2XDl/ZemrkkCn3AaIJkrl4BUzzl1WArWWos3tD5K99/Q4KQgvLw6c+OD635ePgxStD/pivt/JHC/KeLYyq5l89uhkzRKtWnDoIiyHS2o2i7vnRwB4SWxUL1u06jJcDLLSUt7Wd+r3ieiUtHvBaWhXEBEIcmvMXaOA2IjcVH6WjPYgXY4GgnVEQdgZmft0wjPsu+duwx1TWM/C+g9RqSPvq/YZhqQ=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: microsoft.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 4dbb63a6-0779-43fa-f69c-08d6f83779cc
X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Jun 2019 00:04:06.7387
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: mikelley@ntdev.microsoft.com
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR21MB1301
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Thomas Gleixner <tglx@linutronix.de> Sent: Sunday, June 23, 2019 3:13=
 PM
>=20
> I have no objections if you collect hyper-v stuff, quite the contrary, bu=
t
> changes which touch other subsystems need to be coordinated upfront. That=
's
> all I'm asking for.
>=20
> Btw, that clocksource stuff looks good code wise, just the change logs ne=
ed
> some care and after the VDSO stuff hits next we need to sort out the
> logistics. I hope these changes are completely self contained. If not we'=
ll
> find a solution.
>

In my view, the only thing that potentially needs a solution is where the
Hyper-V clock code used by VDSO ends up in the code tree.  I think the
right long term place is include/clocksource/hyperv_timer.h.   That locatio=
n
is architecture neutral, and the same Hyper-V clock code will be shared by
the Hyper-V on ARM64 support that's in process.

Vincenzo's patch set creates a new file arch/x86/include/asm/mshyperv-tsc.h=
,
which I will want to move when creating the separate Hyper-V clocksource
driver.   If you're OK with that file existing for a release and then going=
 away,
that's fine.  Alternatively, put the code in include/clocksource/hyperv_tim=
er.h
now as part of the VDSO patch set so it's in the right place from the start=
.  My
subsequent patch set will add a few additional tweaks to remove x86-isms
and fully integrate with the separate Hyper-V clocksource driver.

Michael=20