From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: Timekeeping on ARM guests/hosts
Date: Wed, 10 Oct 2018 11:01:25 +0100
Message-ID: <cd4eeb25-50c6-329d-d6e8-26caf478a041@arm.com>
References: <CAHSjozDb2_q9YgHsEerH_-2uc6S9W-cw_p2hTiafisQUTrwH6Q@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <kvmarm-bounces@lists.cs.columbia.edu>
Received: from localhost (localhost [127.0.0.1])
 by mm01.cs.columbia.edu (Postfix) with ESMTP id 31F054A20D
 for <kvmarm@lists.cs.columbia.edu>; Wed, 10 Oct 2018 06:01:33 -0400 (EDT)
Received: from mm01.cs.columbia.edu ([127.0.0.1])
 by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024)
 with ESMTP id QjArMnzm9qXM for <kvmarm@lists.cs.columbia.edu>;
 Wed, 10 Oct 2018 06:01:28 -0400 (EDT)
Received: from foss.arm.com (foss.arm.com [217.140.101.70])
 by mm01.cs.columbia.edu (Postfix) with ESMTP id 3887D40A6E
 for <kvmarm@lists.cs.columbia.edu>; Wed, 10 Oct 2018 06:01:28 -0400 (EDT)
In-Reply-To: <CAHSjozDb2_q9YgHsEerH_-2uc6S9W-cw_p2hTiafisQUTrwH6Q@mail.gmail.com>
Content-Language: en-GB
List-Unsubscribe: <https://lists.cs.columbia.edu/mailman/options/kvmarm>,
 <mailto:kvmarm-request@lists.cs.columbia.edu?subject=unsubscribe>
List-Archive: <https://lists.cs.columbia.edu/pipermail/kvmarm>
List-Post: <mailto:kvmarm@lists.cs.columbia.edu>
List-Help: <mailto:kvmarm-request@lists.cs.columbia.edu?subject=help>
List-Subscribe: <https://lists.cs.columbia.edu/mailman/listinfo/kvmarm>,
 <mailto:kvmarm-request@lists.cs.columbia.edu?subject=subscribe>
Errors-To: kvmarm-bounces@lists.cs.columbia.edu
Sender: kvmarm-bounces@lists.cs.columbia.edu
To: Miriam Zimmerman <mutexlox@google.com>, kvmarm@lists.cs.columbia.edu
List-Id: kvmarm@lists.cs.columbia.edu

Hi Myriam,

On 10/10/18 00:39, Miriam Zimmerman wrote:
> Hi,
> 
> I'm working with an ARM device hosting an ARM guest. When the host is 
> suspended, guest time stops advancing and it doesn't get adjusted on resume.

I know the feeling, my arm64 laptop gives me that kind of grief all the 
time... :-/

> For an x86 machine, the CONFIG_KVM_GUEST flag would enable paravirt for 
> time and fix this problem, but CONFIG_KVM_GUEST isn't available on ARM.
> 
> Is there a configuration option to enable paravirtualized timekeeping on 
> ARM? If not, how can I configure ARM guests to handle timekeeping properly?

PV time (or rather stolen time) is a work in progress at the moment, and 
Christoffer has his hands in that particular pie.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...