Received: by 2002:a25:b323:0:0:0:0:0 with SMTP id l35csp1454742ybj; Fri, 20 Sep 2019 10:43:05 -0700 (PDT) X-Google-Smtp-Source: APXvYqxlVp5v+zWoqv4BitA+0h1Rjm5rRTH2USDCT61wTtD6G86b9z1epzkxRg9kWm91iiVGmc4m X-Received: by 2002:aa7:d48f:: with SMTP id b15mr23270789edr.159.1569001385735; Fri, 20 Sep 2019 10:43:05 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1569001385; cv=none; d=google.com; s=arc-20160816; b=rSIgUeIRv3EnrX+Y12OuoKUbQlGiKZyyuuzL9Z2EIpGXa4wgEDP9NlxfmL2DawT8zp XvXeYDhtXhmbNQiuE1Om0bv3C5OqrVkSLy1NiF5jrgrO4K/kDYVeZ997/evaxvArnq5G 6CMKIH9JI4AK5WhDJsAgtsNET/+3Qzuc7n1a2/9L3bpHEwb/wBnheuEan8hq1tbK0v6E +rzwe8FPoHfR6k5uoXCm1/djO70P4oYYMn6d2bfg5CSOmXUybZpIgwUq1td+k2KrqcyP f1ZftZD+BlPYNcolgHk/bDyQBrYZEPdcsiNC7m/g3PUZuWzKUf7ihsuKncQxpsSXOvCi Z3gQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:openpgp:from:references:cc:to:subject; bh=GKORzqIRH8UFUe4Xtmmfu6KCmszYBGYE6BwrxWii7Vw=; b=UURBgrLhiEPe8ZAXXJVfCtLYSqVs0ziMziCxcrTEmKy8vs3FjHXkfb2sqHMKkoKVXX z840T5jN3CTUrws/l27747vfCb7OucxmMTcaaIQlSRwEiPrF4IC1GciCBBCXFFOBE6uv 1hGAONTYZMD0/fzFJ4hVteJiK3HuO1FVVHcYBbHd3Pnc5TNJ1oVje+Es3Hl+cOoX6NKB O+XwZJBPa2qEWHCoafHETkvtX2mS5b9nvsQH1Ych/T3cGmAC6lKvTx30OA3PyYrsWYXY qP+4iUXRx9qkmyLjxJz9fE9+4RN6/y1Ctio6ibi/fg2viX/yS0f92RICGyOh2qTwLmIs AJ2Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id w8si1700092edq.391.2019.09.20.10.42.42; Fri, 20 Sep 2019 10:43:05 -0700 (PDT) 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; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437600AbfITHsF (ORCPT + 99 others); Fri, 20 Sep 2019 03:48:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36566 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437580AbfITHsF (ORCPT ); Fri, 20 Sep 2019 03:48:05 -0400 Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D71DA811DC for ; Fri, 20 Sep 2019 07:48:04 +0000 (UTC) Received: by mail-wm1-f70.google.com with SMTP id k9so833973wmb.0 for ; Fri, 20 Sep 2019 00:48:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=GKORzqIRH8UFUe4Xtmmfu6KCmszYBGYE6BwrxWii7Vw=; b=RvjXeXalP7U6BgX0g3ChcHI2hqxmpsjV510ftitSeOAVVUUBHzrBifja3dPqY2ktze 0jb0fZSNCqPg+QZlaGlCiOHrndTZs4CMXMMgdmbodQ8C5izUOXMgi1stKtxUepdGX7Of NNm0wgGNggJKzPJ8pB9SmGB0up3Kypghhss2oCMbk0qvdLDWcX/VRkK5brUOFXhIrwEU Eb4Yoq4gEfPgFTlip6YQ0LkwTlwS2Sx+Jujp7yIBwnl+MAj/q4+fc0zU6fC1gLG1FpXG XN0GujpIArA1QK8O9c0pPiD2m5fMkN1uKZ1ddWxeo64VR2mkHzTfwK/AFKvdjVrSOosB mZyg== X-Gm-Message-State: APjAAAVXDwuyjj7f418k+S2a38bn4+DrCxPZDdr0400W1RCNG33m5TTk BxR02hzXlxt4OOVA0zqOD+5+WpUD+aLXhPubQBm0wSjdm3zeR+rEZmlix4BemJaH3a31XchOQdb EPIuDwtWOKv3syDlh9VK6KRTv X-Received: by 2002:a5d:4d42:: with SMTP id a2mr11317093wru.89.1568965683591; Fri, 20 Sep 2019 00:48:03 -0700 (PDT) X-Received: by 2002:a5d:4d42:: with SMTP id a2mr11317074wru.89.1568965683377; Fri, 20 Sep 2019 00:48:03 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c46c:2acb:d8d2:21d8? ([2001:b07:6468:f312:c46c:2acb:d8d2:21d8]) by smtp.gmail.com with ESMTPSA id w125sm1665640wmg.32.2019.09.20.00.48.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 Sep 2019 00:48:02 -0700 (PDT) Subject: Re: [RFC 0/2] kvm: Use host timekeeping in guest. To: Suleiman Souhlal , rkrcmar@redhat.com, tglx@linutronix.de Cc: john.stultz@linaro.org, sboyd@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <20190920062713.78503-1-suleiman@google.com> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: <1ec0b238-61a7-8353-026e-3a2ee23e6240@redhat.com> Date: Fri, 20 Sep 2019 09:48:03 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190920062713.78503-1-suleiman@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/09/19 08:27, Suleiman Souhlal wrote: > To do that, I am changing kvmclock to request to the host to copy > its timekeeping parameters (mult, base, cycle_last, etc), so that > the guest timekeeper can use the same values, so that time can > be synchronized between the guest and the host. > > Any suggestions or feedback would be highly appreciated. I'm not a timekeeping maintainer, but I don't think the kernel/time/timekeeping.c changes are acceptable. Is the PTP driver not enough? Paolo