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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,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 10F70C2D0E4 for ; Mon, 23 Nov 2020 10:58:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6DA421D7E for ; Mon, 23 Nov 2020 10:58:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ggZdStaR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728048AbgKWK6P (ORCPT ); Mon, 23 Nov 2020 05:58:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:43186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726289AbgKWK6P (ORCPT ); Mon, 23 Nov 2020 05:58:15 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5037920781; Mon, 23 Nov 2020 10:58:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606129094; bh=/peUmxWwoiuoRZHOUT3CLjXhVSf0z9ZqsFQuW9bn+lU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ggZdStaRDcuClrAZIfESIxlWj27QHDRXUH+C/KbP+gjBJzkGUQ8cNmRBUUeSjPG6F K0qxnr2bzC3wS96VFks2K8I9SDy/jjGygPJY1Sjq0CYXMD8ayNzkFsFPaxMX6wUYaT oae+rHW3jiJs5Cclmn17vL0aVsm3Yjijau6Kl0KA= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kh9Xw-00CtAH-3h; Mon, 23 Nov 2020 10:58:12 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 23 Nov 2020 10:58:07 +0000 From: Marc Zyngier To: Jianyong Wu Cc: netdev@vger.kernel.org, yangbo.lu@nxp.com, john.stultz@linaro.org, tglx@linutronix.de, pbonzini@redhat.com, sean.j.christopherson@intel.com, richardcochran@gmail.com, Mark.Rutland@arm.com, will@kernel.org, suzuki.poulose@arm.com, Andre.Przywara@arm.com, steven.price@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Steve.Capper@arm.com, justin.he@arm.com, nd@arm.com Subject: Re: [PATCH v15 8/9] doc: add ptp_kvm introduction for arm64 support In-Reply-To: <20201111062211.33144-9-jianyong.wu@arm.com> References: <20201111062211.33144-1-jianyong.wu@arm.com> <20201111062211.33144-9-jianyong.wu@arm.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <38fad448a3a465e4c35994ce61f4d8dd@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: jianyong.wu@arm.com, netdev@vger.kernel.org, yangbo.lu@nxp.com, john.stultz@linaro.org, tglx@linutronix.de, pbonzini@redhat.com, sean.j.christopherson@intel.com, richardcochran@gmail.com, Mark.Rutland@arm.com, will@kernel.org, suzuki.poulose@arm.com, Andre.Przywara@arm.com, steven.price@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Steve.Capper@arm.com, justin.he@arm.com, nd@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020-11-11 06:22, Jianyong Wu wrote: > PTP_KVM implementation depends on hypercall using SMCCC. So we > introduce a new SMCCC service ID. This doc explains how does the > ID define and how does PTP_KVM works on arm/arm64. > > Signed-off-by: Jianyong Wu > --- > Documentation/virt/kvm/api.rst | 9 +++++++ > Documentation/virt/kvm/arm/index.rst | 1 + > Documentation/virt/kvm/arm/ptp_kvm.rst | 29 +++++++++++++++++++++ > Documentation/virt/kvm/timekeeping.rst | 35 ++++++++++++++++++++++++++ > 4 files changed, 74 insertions(+) > create mode 100644 Documentation/virt/kvm/arm/ptp_kvm.rst > > diff --git a/Documentation/virt/kvm/api.rst > b/Documentation/virt/kvm/api.rst > index 36d5f1f3c6dd..9843dbcbf770 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -6391,3 +6391,12 @@ When enabled, KVM will disable paravirtual > features provided to the > guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf > (0x40000001). Otherwise, a guest may use the paravirtual features > regardless of what has actually been exposed through the CPUID leaf. > + > +8.27 KVM_CAP_PTP_KVM > +-------------------- > + > +:Architectures: arm64 > + > +This capability indicates that KVM virtual PTP service is supported in > host. > +It must company with the implementation of KVM virtual PTP service in > host > +so VMM can probe if there is the service in host by checking this > capability. > diff --git a/Documentation/virt/kvm/arm/index.rst > b/Documentation/virt/kvm/arm/index.rst > index 3e2b2aba90fc..78a9b670aafe 100644 > --- a/Documentation/virt/kvm/arm/index.rst > +++ b/Documentation/virt/kvm/arm/index.rst > @@ -10,3 +10,4 @@ ARM > hyp-abi > psci > pvtime > + ptp_kvm > diff --git a/Documentation/virt/kvm/arm/ptp_kvm.rst > b/Documentation/virt/kvm/arm/ptp_kvm.rst > new file mode 100644 > index 000000000000..bb1e6cfefe44 > --- /dev/null > +++ b/Documentation/virt/kvm/arm/ptp_kvm.rst > @@ -0,0 +1,29 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +PTP_KVM support for arm/arm64 > +============================= > + > +PTP_KVM is used for time sync between guest and host in a high > precision. > +It needs to get the wall time and counter value from the host and > transfer these > +to guest via hypercall service. So one more hypercall service has been > added. > + > +This new SMCCC hypercall is defined as: > + > +* ARM_SMCCC_HYP_KVM_PTP_FUNC_ID: 0x86000001 > + > +As both 32 and 64-bits ptp_kvm client should be supported, we choose > SMC32/HVC32 > +calling convention. > + > +ARM_SMCCC_HYP_KVM_PTP_FUNC_ID: > + > + ============= ========== ========== > + Function ID: (uint32) 0x86000001 > + Arguments: (uint32) ARM_PTP_PHY_COUNTER(1) or > ARM_PTP_VIRT_COUNTER(0) > + which indicate acquiring physical > counter or > + virtual counter respectively. > + return value: (uint32) NOT_SUPPORTED(-1) or val0 and val1 > represent > + wall clock time and val2 and val3 > represent > + counter cycle. This needs a lot more description: - Which word contains what part of the data (upper/lower part of the 64bit data) - The endianness of the data returned M. -- Jazz is not dead. It just smells funny...