From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 AF942359F81 for ; Sat, 31 Jan 2026 13:29:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769866184; cv=none; b=lxghIdY2VbB6+NC3M8Y+fdsDWvkCzhJNgd+6tFUkKCp6yef0tdjmzMu9G02ID5lvaFSJE0fOIB38ymj5FzCefZqwEbk0+ClHV5jZxhcjzK37VD27xR/qT5YBQjxcxhfwrsfTNxPbaOpHbsDmCdQidTv6fHoT4Czi3jJgCELLuv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769866184; c=relaxed/simple; bh=fhPeQWVBSnCBrnALKVurTRUuPiSMZ+f8M8+cUOxcd9o=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BpCB1N7J+oDmPVwK6+Ec8UG5YhdrAB+xuwyFp1nJtbEcWJNi5CcUdvWb0XMb432pRpT+Nx8DZCaXkf8aizThL2wfy5UnIo7A/UZt+8IGB0F3CXrGAq2olqS8aYxl9NdEzh5HzkhFeEbS8cZxvy51PIkE099EOxQcIkoypVOSAIY= 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=shR+yCPa; arc=none smtp.client-ip=209.85.128.74 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="shR+yCPa" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-4806865a01bso20485845e9.0 for ; Sat, 31 Jan 2026 05:29:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769866180; x=1770470980; 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=goZ+MaQKy7l7B7ncr3K66S9aihGDrIDC3mypa0RPtIo=; b=shR+yCPa5yAlvHuz8iMQb28m8bm+SbLvib+3DZAF1QqMQ9G3hA0pJ1JnjKX3gsps/B AiX0KEY4yih3k0Lqqugl23VheIWccwYTVd4bkMbfBfGEAUXtIQRPvluhe6LAfvCNTz1Q U4i72sPDOaFx1x3juNhgHIFnhS9BDWWTKAbDmFNk1EjlSez4cGVKzDWO2iDfjUml/Md6 zbwXj+2bH9ECyhpX0A51vB7Lzz7Gfat3JDLMYD9dQxNwcR8EoS9AO5sJsMX5TXF3v0t/ 9YSG+SSrbouSiMOcfLohk98g4gVcTiKC1cJSZxD+NFMZtgiXAvidSKN+8VddI7YhRv4m RuaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769866180; x=1770470980; 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=goZ+MaQKy7l7B7ncr3K66S9aihGDrIDC3mypa0RPtIo=; b=aYCHetLTqnSyrKn1Uyw7WqHFDPumjcSzBPyyiSimDlyoK2Cy5F7KnGw9lJ3AaDhaVR beJt72Tc1rI+N4E+8hMa9vRSlHtwIkD4/Uyw6HiCVRjFwMAziQQz55HYPdn8Lz+o9k9c tTqUTKfVtMpWA7FsGbwZFEyikXlrwVLFAdHyi+jrRI60jpf6wuF+2//2aDQU+/DRhLF/ HLHsN0cJPZ9XeMXbnMpwPSHTisalm2fwCm6cQN5dH9OZKd4V0eQycm7bwkp8XHhk1E+P wZd5w7lDhLGoXFfUPTXLGqIQ4BwyaIFFSKcLaZA4XsabJj7HDo5GZrlOSXjCX7Y1KMWX tJMw== X-Forwarded-Encrypted: i=1; AJvYcCXWRu0zl98vSMzgEY1bwAoeBEDB1YbMtkyrOgsBJ52teMgjcsIc5pKxIfVo6ai7f7FhT/Tf32f+K+8RWyyAHOWMdRU=@vger.kernel.org X-Gm-Message-State: AOJu0YycszFG4DJ7SwhXRnFSeytfKw9PQZFKoW4h+tbZwt7YuHEO1Rnt iIzo6docIXqtkp+Ha4e+lmPQqLs/M+MAevA1WMFpBUai1UKmilrbwbnXdBDyN8Cf9QuggZ1Cn2G ms5Yn1CfsSEtk0ck7MAOJjQ== X-Received: from wmz6.prod.google.com ([2002:a05:600c:6b66:b0:480:1b84:b6e]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1da8:b0:480:3a71:92b2 with SMTP id 5b1f17b1804b1-482db498227mr71271215e9.26.1769866180081; Sat, 31 Jan 2026 05:29:40 -0800 (PST) Date: Sat, 31 Jan 2026 13:28:38 +0000 In-Reply-To: <20260131132848.254084-1-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: <20260131132848.254084-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.rc1.225.gd81095ad13-goog Message-ID: <20260131132848.254084-21-vdonnefort@google.com> Subject: [PATCH v11 20/30] 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.rc1.225.gd81095ad13-goog