From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f74.google.com (mail-ed1-f74.google.com [209.85.208.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 672E134D90C for ; Fri, 6 Mar 2026 14:36:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772807776; cv=none; b=CRHcaTv4+wsVw9dWV0GSJoD+vtMozoHiDOQoVn1lcmruXYcoGrP395/XEmMnBvlXRJujKhQJjc/OGVG7JG4UwpUUjtI4Jxkoz6whxDwgReCWksSBuwe4GfBb4wA3iTxaPul4yYaqSPSyJL+5KYPVRYksMSr7StgRhCQFKEq4p6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772807776; c=relaxed/simple; bh=h2rVCYiv2RErJ8J/DPs4R6liat0vq1OWoPSAfx6DS2s=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Ec3ms5IkSvjrjUuF+u0pdqXBcuJkHOhmt9n9tz5mDMAxL9pBionX3qVXSjitme+ydy0R/pE37p6vP3UrgECm0Ak3fOIGSw9n6D/MFpg2z8FwZfC0nCDZsTGmcNxj3EAxv3RXWgJbs8Nv0iw8dd7Y4to9kzUCAgWrp+J6fRJ22kM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=BR06Cbc8; arc=none smtp.client-ip=209.85.208.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="BR06Cbc8" Received: by mail-ed1-f74.google.com with SMTP id 4fb4d7f45d1cf-6613679e8cbso2978031a12.3 for ; Fri, 06 Mar 2026 06:36:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772807773; x=1773412573; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=xnACahr8ULD6CcAQo9gjmAw66hUMbPmLgQ2wO/RqDz0=; b=BR06Cbc8wg5UXrEC0B44krBF2jZP3WL6Jf2GYftbLNkeiZFDkj3QPrwjxPnF7nacvJ hfu/plIGQC6fVjd75jUUeFc16IRPLZIPhJCvp2RsUuKHPR7tWPZmAdwPCuGBIMkNqMNi 5G5Lo2IClVSugXGMnLxxOXHGxN5ym5vgI2VC4TWe7T4ZvPdOq/wkybjSRvKX4EQcSkrs 650yUPiusXFyfT87/umttVDuDNwvCfQuuoH20gLC0xLHfbesVWUS+pQi82OXKzKFUX+3 khUsYNbY7bgpZaFhO1joR2vNM6ggHRGvboMOacxnrFfgeXjPitvw+M5dFnO8Frg6IuRh oKrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772807773; x=1773412573; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=xnACahr8ULD6CcAQo9gjmAw66hUMbPmLgQ2wO/RqDz0=; b=Otkj+M6zTB3hTOWH2kwZFs/ntZTdHOcWQcj9mrLuZOJBZON1GMrWiWWPvPeh9gakRY wn4eefhkrBsgxI9YtlJKklDTgQ/m8lfcGC0go8YnQ1OjOqSLW/2i31+ey+nkqsmE3P30 pZHtUbpM1TMwOwk1Tq5ukG7bAvDl1Q+vfwexmxiXIS87wflZyB57Ntn5JFfiGZlonM/O wsTTSZnmInh9jdVunJJ9Tu4F+vOJ1qVe/u24XGSmaWKkCCxCZbsVcUa7mg1OTtInZyvo RpOPePH06NnF/0c7jqMerlsJPlV2UcV/wz7FZiZ8miK61vWjkB8Qyqnuq6f8F/mIgSm4 +zQA== X-Forwarded-Encrypted: i=1; AJvYcCXkhVz6rF2NWkNdWKt/fNB/qnBjF9IZSGSL3sVLQqjlsHdMlBpy004kOW0t6a7wEimXDNB7QqD7Iwb2y7qJPU356Yo=@vger.kernel.org X-Gm-Message-State: AOJu0Yz7A36V1zBf/nB59Sn49pgncw8HqDW5zfVwn5rPluBO3TuYop2B mUpzrkXuql+mMHmpjbh6TWYMRPjFxl3792ITQNlwxDQyJc16xgkNsur9O2VUI4BeDmy52JmtHsR FO1RDNOY94eOWcSAWFKnzLw== X-Received: from edrs15.prod.google.com ([2002:aa7:c54f:0:b0:660:a4e3:2ed2]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:430c:b0:65a:2ec5:99c0 with SMTP id 4fb4d7f45d1cf-6619d4565b4mr1408474a12.3.1772807772463; Fri, 06 Mar 2026 06:36:12 -0800 (PST) Date: Fri, 6 Mar 2026 14:35:24 +0000 In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260306143536.339777-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260306143536.339777-21-vdonnefort@google.com> Subject: [PATCH v13 20/32] KVM: arm64: Add clock support to nVHE/pKVM hyp From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" In preparation for supporting tracing from the nVHE hyp, add support to generate timestamps with a clock fed by the CNTCVT counter. The clock can be kept in sync with the kernel's by updating the slope values. This will be done later. As current we do only create a trace clock, make the whole support dependent on the upcoming CONFIG_NVHE_EL2_TRACING. Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/include/nvhe/clock.h b/arch/arm64/kvm/hyp/include/nvhe/clock.h new file mode 100644 index 000000000000..9f429f5c0664 --- /dev/null +++ b/arch/arm64/kvm/hyp/include/nvhe/clock.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ARM64_KVM_HYP_NVHE_CLOCK_H +#define __ARM64_KVM_HYP_NVHE_CLOCK_H +#include + +#include + +#ifdef CONFIG_NVHE_EL2_TRACING +void trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc); +u64 trace_clock(void); +#else +static inline void +trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc) { } +static inline u64 trace_clock(void) { return 0; } +#endif +#endif diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index a244ec25f8c5..8dc95257c291 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -17,7 +17,7 @@ ccflags-y += -fno-stack-protector \ hostprogs := gen-hyprel HOST_EXTRACFLAGS += -I$(objtree)/include -lib-objs := clear_page.o copy_page.o memcpy.o memset.o +lib-objs := clear_page.o copy_page.o memcpy.o memset.o tishift.o lib-objs := $(addprefix ../../../lib/, $(lib-objs)) CFLAGS_switch.nvhe.o += -Wno-override-init @@ -29,6 +29,7 @@ hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o hyp-obj-y += ../../../kernel/smccc-call.o hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o +hyp-obj-$(CONFIG_NVHE_EL2_TRACING) += clock.o hyp-obj-y += $(lib-objs) ## diff --git a/arch/arm64/kvm/hyp/nvhe/clock.c b/arch/arm64/kvm/hyp/nvhe/clock.c new file mode 100644 index 000000000000..32fc4313fe43 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/clock.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2025 Google LLC + * Author: Vincent Donnefort + */ + +#include + +#include +#include + +static struct clock_data { + struct { + u32 mult; + u32 shift; + u64 epoch_ns; + u64 epoch_cyc; + u64 cyc_overflow64; + } data[2]; + u64 cur; +} trace_clock_data; + +static u64 __clock_mult_uint128(u64 cyc, u32 mult, u32 shift) +{ + __uint128_t ns = (__uint128_t)cyc * mult; + + ns >>= shift; + + return (u64)ns; +} + +/* Does not guarantee no reader on the modified bank. */ +void trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc) +{ + struct clock_data *clock = &trace_clock_data; + u64 bank = clock->cur ^ 1; + + clock->data[bank].mult = mult; + clock->data[bank].shift = shift; + clock->data[bank].epoch_ns = epoch_ns; + clock->data[bank].epoch_cyc = epoch_cyc; + clock->data[bank].cyc_overflow64 = ULONG_MAX / mult; + + smp_store_release(&clock->cur, bank); +} + +/* Use untrusted host data */ +u64 trace_clock(void) +{ + struct clock_data *clock = &trace_clock_data; + u64 bank = smp_load_acquire(&clock->cur); + u64 cyc, ns; + + cyc = __arch_counter_get_cntvct() - clock->data[bank].epoch_cyc; + + if (likely(cyc < clock->data[bank].cyc_overflow64)) { + ns = cyc * clock->data[bank].mult; + ns >>= clock->data[bank].shift; + } else { + ns = __clock_mult_uint128(cyc, clock->data[bank].mult, + clock->data[bank].shift); + } + + return (u64)ns + clock->data[bank].epoch_ns; +} -- 2.53.0.473.g4a7958ca14-goog