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=-14.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 7CEEFC56202 for ; Mon, 23 Nov 2020 10:45:31 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 F06102076E for ; Mon, 23 Nov 2020 10:45:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BfNdFkOK"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hTJmXcNr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F06102076E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=g0Ugz56wsAfcyTB2X7lLGu7BbD/hPlnbm7QtfYgqlYw=; b=BfNdFkOKqRiWAnQvEQP43SE7I b77WIvTHsTIq3u3RHuNXrEMWbXoXJJW39iSiZDFxaj6l2AYKiYceRlAuqF351hO6Lt+pj9SXwNgcH Q36WGHz/dREakz2Nlv0bWRZqls7P/82JB4H5CtkkQV9eWFVAF1CVsom7cy9ZYzGF/fo4LEEfVyqzw dxv2t79ptyv5QcIl5pDtIxw9pbF56vaMZRcxg8vjGVqutKJnpsIXfuaLGqUZO+OO60ns+gTacz2It 03zpNWKcK1QY/6/PcxKT4S89nbFjEg59VAMuDfc6Pg3UmcEFSypIFZZ47sXh/1C8zPRxUv3B58GMS JArztnhHw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kh9KU-0005gI-J2; Mon, 23 Nov 2020 10:44:18 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kh9KR-0005fc-Oe for linux-arm-kernel@lists.infradead.org; Mon, 23 Nov 2020 10:44:16 +0000 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 691AB2076E; Mon, 23 Nov 2020 10:44:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606128254; bh=0i/Ni3kZzV5fbIzNzcjmFGKPO1GlWbvJIDpSsaZ7xz8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=hTJmXcNrqPN4TANS18R1jlGBzZajV2aUWLpzDTGH88XrxC87G+t/jopKrepNEeLwm 0+rqIZem3eap2IfVbXVwyersh3veLjNERXei8VwYWymhk4/paAWd+W/p7rGHrkcnXm +pjqXMdHX44U546hSqPOzry+sdpQiJe1afKpQhWs= 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 1kh9KO-00Csxc-6S; Mon, 23 Nov 2020 10:44:12 +0000 MIME-Version: 1.0 Date: Mon, 23 Nov 2020 10:44:12 +0000 From: Marc Zyngier To: Jianyong Wu Subject: Re: [PATCH v15 6/9] arm64/kvm: Add hypercall service for kvm ptp. In-Reply-To: <20201111062211.33144-7-jianyong.wu@arm.com> References: <20201111062211.33144-1-jianyong.wu@arm.com> <20201111062211.33144-7-jianyong.wu@arm.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201123_054415_986603_72BA4C5E X-CRM114-Status: GOOD ( 25.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark.Rutland@arm.com, justin.he@arm.com, kvm@vger.kernel.org, suzuki.poulose@arm.com, netdev@vger.kernel.org, richardcochran@gmail.com, Steve.Capper@arm.com, linux-kernel@vger.kernel.org, sean.j.christopherson@intel.com, steven.price@arm.com, Andre.Przywara@arm.com, john.stultz@linaro.org, yangbo.lu@nxp.com, pbonzini@redhat.com, tglx@linutronix.de, nd@arm.com, will@kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-11-11 06:22, Jianyong Wu wrote: > ptp_kvm will get this service through SMCC call. > The service offers wall time and cycle count of host to guest. > The caller must specify whether they want the host cycle count > or the difference between host cycle count and cntvoff. > > Signed-off-by: Jianyong Wu > --- > arch/arm64/kvm/hypercalls.c | 61 +++++++++++++++++++++++++++++++++++++ > include/linux/arm-smccc.h | 17 +++++++++++ > 2 files changed, 78 insertions(+) > > diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c > index b9d8607083eb..f7d189563f3d 100644 > --- a/arch/arm64/kvm/hypercalls.c > +++ b/arch/arm64/kvm/hypercalls.c > @@ -9,6 +9,51 @@ > #include > #include > > +static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val) > +{ > + struct system_time_snapshot systime_snapshot; > + u64 cycles = ~0UL; > + u32 feature; > + > + /* > + * system time and counter value must captured in the same > + * time to keep consistency and precision. > + */ > + ktime_get_snapshot(&systime_snapshot); > + > + // binding ptp_kvm clocksource to arm_arch_counter > + if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER) > + return; > + > + val[0] = upper_32_bits(systime_snapshot.real); > + val[1] = lower_32_bits(systime_snapshot.real); What is the endianness of these values? I can't see it defined anywhere, and this is likely not to work if guest and hypervisor don't align. > + > + /* > + * which of virtual counter or physical counter being > + * asked for is decided by the r1 value of SMCCC > + * call. If no invalid r1 value offered, default cycle > + * value(-1) will be returned. > + * Note: keep in mind that feature is u32 and smccc_get_arg1 > + * will return u64, so need auto cast here. > + */ > + feature = smccc_get_arg1(vcpu); > + switch (feature) { > + case ARM_PTP_VIRT_COUNTER: > + cycles = systime_snapshot.cycles - vcpu_read_sys_reg(vcpu, > CNTVOFF_EL2); > + break; > + case ARM_PTP_PHY_COUNTER: > + cycles = systime_snapshot.cycles; > + break; > + case ARM_PTP_NONE_COUNTER: What is this "NONE" counter? > + break; > + default: > + val[0] = SMCCC_RET_NOT_SUPPORTED; > + break; > + } > + val[2] = upper_32_bits(cycles); > + val[3] = lower_32_bits(cycles); Same problem as above. > +} > + > int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) > { > u32 func_id = smccc_get_function(vcpu); > @@ -79,6 +124,22 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) > break; > case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID: > val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES); > + val[0] |= BIT(ARM_SMCCC_KVM_FUNC_KVM_PTP); > + break; > + /* > + * This serves virtual kvm_ptp. > + * Four values will be passed back. > + * reg0 stores high 32-bits of host ktime; > + * reg1 stores low 32-bits of host ktime; > + * For ARM_PTP_VIRT_COUNTER: > + * reg2 stores high 32-bits of difference of host cycles and cntvoff; > + * reg3 stores low 32-bits of difference of host cycles and cntvoff. > + * For ARM_PTP_PHY_COUNTER: > + * reg2 stores the high 32-bits of host cycles; > + * reg3 stores the low 32-bits of host cycles. > + */ > + case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: > + kvm_ptp_get_time(vcpu, val); > break; > default: > return kvm_psci_call(vcpu); > diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h > index d75408141137..a03c5dd409d3 100644 > --- a/include/linux/arm-smccc.h > +++ b/include/linux/arm-smccc.h > @@ -103,6 +103,7 @@ > > /* KVM "vendor specific" services */ > #define ARM_SMCCC_KVM_FUNC_FEATURES 0 > +#define ARM_SMCCC_KVM_FUNC_KVM_PTP 1 I think having KVM once in the name is enough. > #define ARM_SMCCC_KVM_FUNC_FEATURES_2 127 > #define ARM_SMCCC_KVM_NUM_FUNCS 128 > > @@ -114,6 +115,22 @@ > > #define SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED 1 > > +/* > + * ptp_kvm is a feature used for time sync between vm and host. > + * ptp_kvm module in guest kernel will get service from host using > + * this hypercall ID. > + */ > +#define ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID \ > + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ > + ARM_SMCCC_SMC_32, \ > + ARM_SMCCC_OWNER_VENDOR_HYP, \ > + ARM_SMCCC_KVM_FUNC_KVM_PTP) > + > +/* ptp_kvm counter type ID */ > +#define ARM_PTP_VIRT_COUNTER 0 > +#define ARM_PTP_PHY_COUNTER 1 > +#define ARM_PTP_NONE_COUNTER 2 The architecture definitely doesn't have this last counter. > + > /* Paravirtualised time calls (defined by ARM DEN0057A) */ > #define ARM_SMCCC_HV_PV_TIME_FEATURES \ > ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel