From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08851C43462 for ; Tue, 11 May 2021 09:08:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAA01613B6 for ; Tue, 11 May 2021 09:08:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231286AbhEKJJX (ORCPT ); Tue, 11 May 2021 05:09:23 -0400 Received: from mail-vs1-f52.google.com ([209.85.217.52]:45980 "EHLO mail-vs1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231189AbhEKJJS (ORCPT ); Tue, 11 May 2021 05:09:18 -0400 Received: by mail-vs1-f52.google.com with SMTP id x188so4253750vsx.12; Tue, 11 May 2021 02:08:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VWZENhS44KnEbYhJ55uNu4C5dSY972Eyg88PLcY/zho=; b=ZYteCF6VMnbzLPAL9iAFHg4dIeYly3O1jQ5AW5JJ2oPvkDf9qaHUYPPSTqgNsxT5sH z3T+D/pKNKeSsu6YOS9dBxElcxnKDvYdOPgcyDCb/u+Rjyfpj745mOZI32j9IjihwyUr 18QVNg5hgXGFGwhICErwrs1obuxQToEcdsLOybILakDy3FOXo5qg9Unde5N9jpGNBfOg ksriRNSbrosR5iE6bMuQAlm+SInUEV4H0lm9pFhk+oCD0yP23p/y3/6M5kGXwnXTYgNz 2yQHWt/hx0eOG6fgVYxpn8Wuy1dv/f+HlL2gT5ilUwr//ZgxrlhnrNooAhGHlRhAGFyS YgiQ== X-Gm-Message-State: AOAM532nrO/G0LpWV4ZfZEqMlg+EpjJ40uVfT8BX5GGt+EPxoDpKK11r EdBs9u0cwCTCCcNf2gDYQKoQKiMkGjRtKiOxI+M= X-Google-Smtp-Source: ABdhPJweTlTBbaLMWAGki0KxVFdQqpl/ZcfogWI1Lhfowsw6ZamthDcv+jjw6/wD3nCQ2Fi0vyUoOcx9OTMR/abE99c= X-Received: by 2002:a67:3113:: with SMTP id x19mr17992653vsx.40.1620724090696; Tue, 11 May 2021 02:08:10 -0700 (PDT) MIME-Version: 1.0 References: <20210330145430.996981-1-maz@kernel.org> <20210330145430.996981-8-maz@kernel.org> In-Reply-To: <20210330145430.996981-8-maz@kernel.org> From: Geert Uytterhoeven Date: Tue, 11 May 2021 11:07:59 +0200 Message-ID: Subject: Re: [PATCH v19 7/7] ptp: arm/arm64: Enable ptp_kvm for arm/arm64 To: Marc Zyngier , jianyong.wu@arm.com Cc: netdev , Yangbo Lu , John Stultz , Thomas Gleixner , Paolo Bonzini , seanjc@google.com, Richard Cochran , Mark Rutland , Will Deacon , Suzuki K Poulose , Andre Przywara , Steven Price , Lorenzo Pieralisi , Sudeep Holla , Linux Kernel Mailing List , Linux ARM , kvmarm@lists.cs.columbia.edu, KVM list , Steve Capper , justin.he@arm.com, Android Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marc, Jianyong, On Tue, Mar 30, 2021 at 4:56 PM Marc Zyngier wrote: > From: Jianyong Wu > > Currently, there is no mechanism to keep time sync between guest and host > in arm/arm64 virtualization environment. Time in guest will drift compared > with host after boot up as they may both use third party time sources > to correct their time respectively. The time deviation will be in order > of milliseconds. But in some scenarios,like in cloud environment, we ask > for higher time precision. > > kvm ptp clock, which chooses the host clock source as a reference > clock to sync time between guest and host, has been adopted by x86 > which takes the time sync order from milliseconds to nanoseconds. > > This patch enables kvm ptp clock for arm/arm64 and improves clock sync precision > significantly. > --- a/drivers/ptp/Kconfig > +++ b/drivers/ptp/Kconfig > @@ -108,7 +108,7 @@ config PTP_1588_CLOCK_PCH > config PTP_1588_CLOCK_KVM > tristate "KVM virtual PTP clock" > depends on PTP_1588_CLOCK > - depends on KVM_GUEST && X86 > + depends on (KVM_GUEST && X86) || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER) Why does this not depend on KVM_GUEST on ARM? I.e. shouldn't the dependency be: KVM_GUEST && (X86 || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER)) ? > default y > help > This driver adds support for using kvm infrastructure as a PTP Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB5DEC433ED for ; Tue, 11 May 2021 09:08:16 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 25B4F61932 for ; Tue, 11 May 2021 09:08:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25B4F61932 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 828EC4B4BD; Tue, 11 May 2021 05:08:15 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu 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 XvlfvS7HWPNi; Tue, 11 May 2021 05:08:14 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 67B2B4B49F; Tue, 11 May 2021 05:08:14 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 8502B4B487 for ; Tue, 11 May 2021 05:08:12 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu 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 t9qa2TOwrYIy for ; Tue, 11 May 2021 05:08:11 -0400 (EDT) Received: from mail-vs1-f50.google.com (mail-vs1-f50.google.com [209.85.217.50]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 241664B41D for ; Tue, 11 May 2021 05:08:11 -0400 (EDT) Received: by mail-vs1-f50.google.com with SMTP id l4so2997070vsa.1 for ; Tue, 11 May 2021 02:08:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VWZENhS44KnEbYhJ55uNu4C5dSY972Eyg88PLcY/zho=; b=jNsEvOaHhk8ePOJH2l7hwvRPokRCSmMyFJPmc7X6ncVtkXq6Oy/7T7+47jI3B2wSmQ OTPJHBOWwHmJGmcTT9ilQQPPkf/yR842vVjNOMASPT4L0TbLcyL3y+VCF0BQT0VfdUDS hPe+X7ey9aIYbm8AOQ/osAB1N2ZapnUJPCfpMlKX0PGF8/EfeNuBt1rYfBWyD2CVPSgH FXnOvoFhJirX6yWy2XwE/5v8oRYRDMJFuRMopEeY8Ovq4daxrUdGzu3y/gxLPhn0znN7 utaZ2bY+Ki7R8RhdLEYWKucC3UHtQjGYP9ee31rVFZfDB8wFRK79srx/XVLX0ZzN8L06 VeNg== X-Gm-Message-State: AOAM530iB9jzQRVlCfF+5K3AsR/AeApcZP9otSLi1lrf4na7D2O7ufR4 T/LCQcC7gBQB2RPGEjZ0ZtXtgZFm7PiepHKi7wI= X-Google-Smtp-Source: ABdhPJweTlTBbaLMWAGki0KxVFdQqpl/ZcfogWI1Lhfowsw6ZamthDcv+jjw6/wD3nCQ2Fi0vyUoOcx9OTMR/abE99c= X-Received: by 2002:a67:3113:: with SMTP id x19mr17992653vsx.40.1620724090696; Tue, 11 May 2021 02:08:10 -0700 (PDT) MIME-Version: 1.0 References: <20210330145430.996981-1-maz@kernel.org> <20210330145430.996981-8-maz@kernel.org> In-Reply-To: <20210330145430.996981-8-maz@kernel.org> From: Geert Uytterhoeven Date: Tue, 11 May 2021 11:07:59 +0200 Message-ID: Subject: Re: [PATCH v19 7/7] ptp: arm/arm64: Enable ptp_kvm for arm/arm64 To: Marc Zyngier , jianyong.wu@arm.com Cc: Android Kernel Team , Lorenzo Pieralisi , justin.he@arm.com, KVM list , netdev , Richard Cochran , Yangbo Lu , Sudeep Holla , Steven Price , Andre Przywara , John Stultz , Linux ARM , seanjc@google.com, Paolo Bonzini , Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu, Linux Kernel Mailing List X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Hi Marc, Jianyong, On Tue, Mar 30, 2021 at 4:56 PM Marc Zyngier wrote: > From: Jianyong Wu > > Currently, there is no mechanism to keep time sync between guest and host > in arm/arm64 virtualization environment. Time in guest will drift compared > with host after boot up as they may both use third party time sources > to correct their time respectively. The time deviation will be in order > of milliseconds. But in some scenarios,like in cloud environment, we ask > for higher time precision. > > kvm ptp clock, which chooses the host clock source as a reference > clock to sync time between guest and host, has been adopted by x86 > which takes the time sync order from milliseconds to nanoseconds. > > This patch enables kvm ptp clock for arm/arm64 and improves clock sync precision > significantly. > --- a/drivers/ptp/Kconfig > +++ b/drivers/ptp/Kconfig > @@ -108,7 +108,7 @@ config PTP_1588_CLOCK_PCH > config PTP_1588_CLOCK_KVM > tristate "KVM virtual PTP clock" > depends on PTP_1588_CLOCK > - depends on KVM_GUEST && X86 > + depends on (KVM_GUEST && X86) || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER) Why does this not depend on KVM_GUEST on ARM? I.e. shouldn't the dependency be: KVM_GUEST && (X86 || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER)) ? > default y > help > This driver adds support for using kvm infrastructure as a PTP Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CCC6C433B4 for ; Tue, 11 May 2021 12:30:47 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 82E366191D for ; 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Tue, 11 May 2021 02:08:10 -0700 (PDT) MIME-Version: 1.0 References: <20210330145430.996981-1-maz@kernel.org> <20210330145430.996981-8-maz@kernel.org> In-Reply-To: <20210330145430.996981-8-maz@kernel.org> From: Geert Uytterhoeven Date: Tue, 11 May 2021 11:07:59 +0200 Message-ID: Subject: Re: [PATCH v19 7/7] ptp: arm/arm64: Enable ptp_kvm for arm/arm64 To: Marc Zyngier , jianyong.wu@arm.com Cc: netdev , Yangbo Lu , John Stultz , Thomas Gleixner , Paolo Bonzini , seanjc@google.com, Richard Cochran , Mark Rutland , Will Deacon , Suzuki K Poulose , Andre Przywara , Steven Price , Lorenzo Pieralisi , Sudeep Holla , Linux Kernel Mailing List , Linux ARM , kvmarm@lists.cs.columbia.edu, KVM list , Steve Capper , justin.he@arm.com, Android Kernel Team X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210511_020815_388671_0AA0C111 X-CRM114-Status: GOOD ( 25.73 ) /bin/ln: failed to access 'reaver_cache/texts/20210511_020815_388671_0AA0C111': No such file or directory X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210511_020815_388671_0AA0C111 X-CRM114-Status: GOOD ( 20.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Marc, Jianyong, On Tue, Mar 30, 2021 at 4:56 PM Marc Zyngier wrote: > From: Jianyong Wu > > Currently, there is no mechanism to keep time sync between guest and host > in arm/arm64 virtualization environment. Time in guest will drift compared > with host after boot up as they may both use third party time sources > to correct their time respectively. The time deviation will be in order > of milliseconds. But in some scenarios,like in cloud environment, we ask > for higher time precision. > > kvm ptp clock, which chooses the host clock source as a reference > clock to sync time between guest and host, has been adopted by x86 > which takes the time sync order from milliseconds to nanoseconds. > > This patch enables kvm ptp clock for arm/arm64 and improves clock sync precision > significantly. > --- a/drivers/ptp/Kconfig > +++ b/drivers/ptp/Kconfig > @@ -108,7 +108,7 @@ config PTP_1588_CLOCK_PCH > config PTP_1588_CLOCK_KVM > tristate "KVM virtual PTP clock" > depends on PTP_1588_CLOCK > - depends on KVM_GUEST && X86 > + depends on (KVM_GUEST && X86) || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER) Why does this not depend on KVM_GUEST on ARM? I.e. shouldn't the dependency be: KVM_GUEST && (X86 || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER)) ? > default y > help > This driver adds support for using kvm infrastructure as a PTP Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel