From patchwork Fri May 22 08:37:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jianyong Wu X-Patchwork-Id: 11565053 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2C92113B1 for ; Fri, 22 May 2020 08:38:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FF9020826 for ; Fri, 22 May 2020 08:38:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729990AbgEVIir (ORCPT ); Fri, 22 May 2020 04:38:47 -0400 Received: from foss.arm.com ([217.140.110.172]:59512 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729432AbgEVIio (ORCPT ); Fri, 22 May 2020 04:38:44 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A98C21042; Fri, 22 May 2020 01:38:43 -0700 (PDT) Received: from entos-d05.shanghai.arm.com (entos-d05.shanghai.arm.com [10.169.40.35]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id CE0E13F52E; Fri, 22 May 2020 01:38:37 -0700 (PDT) From: Jianyong Wu To: netdev@vger.kernel.org, yangbo.lu@nxp.com, john.stultz@linaro.org, tglx@linutronix.de, pbonzini@redhat.com, sean.j.christopherson@intel.com, maz@kernel.org, richardcochran@gmail.com, Mark.Rutland@arm.com, will@kernel.org, suzuki.poulose@arm.com, steven.price@arm.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Steve.Capper@arm.com, Kaly.Xin@arm.com, justin.he@arm.com, Wei.Chen@arm.com, jianyong.wu@arm.com, nd@arm.com Subject: [RFC PATCH v12 10/11] arm64: add mechanism to let user choose which counter to return Date: Fri, 22 May 2020 16:37:23 +0800 Message-Id: <20200522083724.38182-11-jianyong.wu@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200522083724.38182-1-jianyong.wu@arm.com> References: <20200522083724.38182-1-jianyong.wu@arm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In general, vm inside will use virtual counter compered with host use phyical counter. But in some special scenarios, like nested virtualization, phyical counter maybe used by vm. A interface added in ptp_kvm driver to offer a mechanism to let user choose which counter should be return from host. To use this feature, you should call PTP_EXTTS_REQUEST(2) ioctl with flag set bit PTP_KVM_ARM_PHY_COUNTER in its argument then call PTP_SYS_OFFSET_PRECISE(2) ioctl to get the cross timestamp and phyical counter will return. If the bit not set or no call for PTP_EXTTS_REQUEST2, virtual counter will return by default. Signed-off-by: Jianyong Wu Suggested-by: Marc Zyngier --- drivers/clocksource/arm_arch_timer.c | 13 ++++++++++++- drivers/ptp/ptp_chardev.c | 25 +++++++++++++++++++++++++ drivers/ptp/ptp_kvm_common.c | 7 ++++--- include/uapi/linux/ptp_clock.h | 4 +++- 4 files changed, 44 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 06959b901b0d..75a3bb118201 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -1650,7 +1650,18 @@ int kvm_arch_ptp_get_crosststamp(unsigned long *cycle, struct timespec64 *ts, struct arm_smccc_res hvc_res; ktime_t ktime_overall; - arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, &hvc_res); + /* + * an argument will be passed by a0 to determine weather virtual + * counter or phyical counter should be passed back. + */ + if (ctx && *ctx) + arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, + ARM_SMCCC_VENDOR_HYP_KVM_PTP_PHY_FUNC_ID, + &hvc_res); + else + arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, + &hvc_res); + if ((int)(hvc_res.a0) < 0) return -EOPNOTSUPP; diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index fef72f29f3c8..8b0a7b328bcd 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -123,6 +123,9 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) struct timespec64 ts; int enable, err = 0; +#ifdef CONFIG_ARM64 + static long flag; +#endif switch (cmd) { case PTP_CLOCK_GETCAPS: @@ -149,6 +152,24 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) err = -EFAULT; break; } + +#ifdef CONFIG_ARM64 + /* + * Just using this ioctl to tell kvm ptp driver to get PHC + * with physical counter, so if bit PTP_KVM_ARM_PHY_COUNTER + * is set then just exit directly. + * In most cases, we just need virtual counter from host and + * there is limited scenario using this to get physical counter + * in guest. + * Be careful to use this as there is no way to set it back + * unless you reinstall the module. + * This is only for arm64. + */ + if (req.extts.flags & PTP_KVM_ARM_PHY_COUNTER) { + flag = 1; + break; + } +#endif if (cmd == PTP_EXTTS_REQUEST2) { /* Tell the drivers to check the flags carefully. */ req.extts.flags |= PTP_STRICT_FLAGS; @@ -235,7 +256,11 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) err = -EOPNOTSUPP; break; } +#ifdef CONFIG_ARM64 + err = ptp->info->getcrosststamp(ptp->info, &xtstamp, &flag); +#else err = ptp->info->getcrosststamp(ptp->info, &xtstamp, NULL); +#endif if (err) break; diff --git a/drivers/ptp/ptp_kvm_common.c b/drivers/ptp/ptp_kvm_common.c index 4fdd8ab11a28..39367e230176 100644 --- a/drivers/ptp/ptp_kvm_common.c +++ b/drivers/ptp/ptp_kvm_common.c @@ -36,7 +36,7 @@ static int ptp_kvm_get_time_fn(ktime_t *device_time, spin_lock(&kvm_ptp_lock); preempt_disable_notrace(); - ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs); + ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs, ctx); if (ret != 0) { pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret); spin_unlock(&kvm_ptp_lock); @@ -57,9 +57,10 @@ static int ptp_kvm_get_time_fn(ktime_t *device_time, } static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp, - struct system_device_crosststamp *xtstamp) + struct system_device_crosststamp *xtstamp, + long *flag) { - return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL, + return get_device_system_crosststamp(ptp_kvm_get_time_fn, flag, NULL, xtstamp); } diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h index 9dc9d0079e98..71e388a82244 100644 --- a/include/uapi/linux/ptp_clock.h +++ b/include/uapi/linux/ptp_clock.h @@ -32,6 +32,7 @@ #define PTP_RISING_EDGE (1<<1) #define PTP_FALLING_EDGE (1<<2) #define PTP_STRICT_FLAGS (1<<3) +#define PTP_KVM_ARM_PHY_COUNTER (1<<4) #define PTP_EXTTS_EDGES (PTP_RISING_EDGE | PTP_FALLING_EDGE) /* @@ -40,7 +41,8 @@ #define PTP_EXTTS_VALID_FLAGS (PTP_ENABLE_FEATURE | \ PTP_RISING_EDGE | \ PTP_FALLING_EDGE | \ - PTP_STRICT_FLAGS) + PTP_STRICT_FLAGS | \ + PTP_KVM_ARM_PHY_COUNTER) /* * flag fields valid for the original PTP_EXTTS_REQUEST ioctl.