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 B9B45448D13 for ; Wed, 15 Jul 2026 11:59:15 +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=1784116757; cv=none; b=XES+Ju1UiRm/5V8aYsmhwQbASzutk2yYrg9HKJS1yFs71iAyaKiKVSpkmTUi9lgDfzJHMwpb41ojexGx1pD/VztaTAQWi2z9RJfZv4oClYjVcl+1lSgDKF2W1NudHiH1pYXngIAowQ2x953L9yVAd39uyU1NvpOlPcTTRTitl0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784116757; c=relaxed/simple; bh=l/hpWbBATRgNusqw4IkGxPNUk54fHjitd3cZTYOU0Us=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=gT3Dn9Mv4RDfPGdjio6ACSaz7KCgetssvuG7e4F7DzWbDOBh5PVC+yZnzoS9gE61fF3gEW+QSbjkRRsDFx480B4EM6nz3K0AUvNdocodRoSt9dHMLOw1x3TLuCiUZJV4OSBablnfIkcq3K0gJfneFZ9aiNWdCpTs+nfP95T32MY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=jLv4MmxW; 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--smostafa.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jLv4MmxW" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-493b21b1fe8so18017645e9.0 for ; Wed, 15 Jul 2026 04:59:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784116754; x=1784721554; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=ol5Kv9IuMOC5gLvUo+ftrDGNdodUvogtRoPdfqHnaTA=; b=jLv4MmxWsUkmO1NIY0lry557eRIAGnz6s0si2IibyBHmS1LBDNsbGx6ukTwbvYH59T 30KobxENxHsHxeux3/QomYoN11W1N4qHnDjvsoXiiqIHt9FGzQGoGJ8JPUFw89cfz8bq bR6G/PCeOdOqjgr2xpQeIZ9HuRqeKygMkImpldIc+rXb1oah1ZDXoQN/sO6973viYhZf SJ0YJ9AlVgFEcgYDVwikADUay8tPsUO7wASpzq9AE/vMjV9XBhenZlpechmxaqpNfLSP hENEocHfIHrPnInLyqFcxoih707lV/G+EFs6Q9TWJAlIJ4MNbHUioMWtGPS/tTDoqyoL kDmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784116754; x=1784721554; h=content-type: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:content-type; bh=ol5Kv9IuMOC5gLvUo+ftrDGNdodUvogtRoPdfqHnaTA=; b=qdPSmi5pzkGAuOOnSbLl8hQeDsHf+ti0Kg9Q1SAgsisY724YKrWCGUQexFyR5CmX7g dQ4KCtq0KiG5n+pY6bJzRhWS2NKByFOd6mMYenVFNMSF4+yrH3yM1NvlBSz9FjsHze1t AVRGLXr6bfjtILiHGfvGLRi7GN80AgpZDfB2+5nvHvnQnEm1ZsVG9RcVEWEQddJJ/hUk OeEO8b7E+PD/47E5y6/7bUY8ApBRrgoLwdFj4Y/6q5oBeUeuiRkujf2yaEm2sfmPXxGZ 2zvR+zXukZXoZnNew/ERWXuBB9cSaUltIP2MmCAPW5lAZcLjBKkDUkfNCGFakALAdLZW 5zcQ== X-Forwarded-Encrypted: i=1; AHgh+RpCZgN7FAlqni6jDCtoEqeNA3wcOjtnCwYb1b+g1Gj8ij2scCQpd9mysWj65xUThaW/O5x39w==@lists.linux.dev X-Gm-Message-State: AOJu0YyfaFE0oZpMtESwpKSmZsQ/UBT7mm2owT4o+AMIDbE3c7YW1eZl 3EdcwMKLT+9V0Y+YRxH57XWZ7rRPdyDcFWMzXEnG7J6FklyWuPQUzGtYXkHryA5DKEHyYaALXqM 8PKqmctvkpxxd4g== X-Received: from wmbe13.prod.google.com ([2002:a05:600c:590d:b0:493:bb14:ecfa]) (user=smostafa job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3f06:b0:495:3c8c:c16a with SMTP id 5b1f17b1804b1-4953c8cc25bmr27537525e9.0.1784116753865; Wed, 15 Jul 2026 04:59:13 -0700 (PDT) Date: Wed, 15 Jul 2026 11:58:42 +0000 In-Reply-To: <20260715115906.2664882-1-smostafa@google.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260715115906.2664882-1-smostafa@google.com> X-Mailer: git-send-email 2.55.0.141.g00534a21ce-goog Message-ID: <20260715115906.2664882-2-smostafa@google.com> Subject: [PATCH v7 01/24] KVM: arm64: Add a generic clock From: Mostafa Saleh To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, iommu@lists.linux.dev Cc: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, joro@8bytes.org, jgg@ziepe.ca, mark.rutland@arm.com, qperret@google.com, tabba@google.com, vdonnefort@google.com, sebastianene@google.com, keirf@google.com, Mostafa Saleh Content-Type: text/plain; charset="UTF-8" IOMMU drivers need to track time, mainly for timeouts. Add 2 new functions to nvhe/clock.c: - hyp_clock_init(): Get the system timer frequency at boot - hyp_clock_ns(): Get current time in nano seconds. This is mainly used for timeouts, so a malicious host can DoS the system or cause premature timeouts which likely end up in hyp panic, that should be acceptable as neither of those would undermine the security guarantees. Signed-off-by: Mostafa Saleh --- arch/arm64/kvm/hyp/include/nvhe/clock.h | 3 +++ arch/arm64/kvm/hyp/nvhe/Makefile | 4 ++-- arch/arm64/kvm/hyp/nvhe/clock.c | 29 +++++++++++++++++++++++++ arch/arm64/kvm/hyp/nvhe/setup.c | 5 +++++ 4 files changed, 39 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/clock.h b/arch/arm64/kvm/hyp/include/nvhe/clock.h index ae03ec6965af..7ef982939bf9 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/clock.h +++ b/arch/arm64/kvm/hyp/include/nvhe/clock.h @@ -13,4 +13,7 @@ static inline void trace_hyp_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc) { } static inline u64 trace_hyp_clock(void) { return 0; } #endif + +u64 hyp_clock_ns(void); +int hyp_clock_init(void); #endif diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index f57450ebcb49..7c879292974d 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -26,10 +26,10 @@ hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \ cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ - ../hyp-entry.o ../exception.o ../pgtable.o ../vgic-v5-sr.o + ../hyp-entry.o ../exception.o ../pgtable.o ../vgic-v5-sr.o clock.o hyp-obj-y += ../../../kernel/smccc-call.o hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o -hyp-obj-$(CONFIG_NVHE_EL2_TRACING) += clock.o trace.o events.o +hyp-obj-$(CONFIG_NVHE_EL2_TRACING) += trace.o events.o hyp-obj-y += $(lib-objs) # Path to simple_ring_buffer.c diff --git a/arch/arm64/kvm/hyp/nvhe/clock.c b/arch/arm64/kvm/hyp/nvhe/clock.c index f3e2619db4e4..43d2cba4f810 100644 --- a/arch/arm64/kvm/hyp/nvhe/clock.c +++ b/arch/arm64/kvm/hyp/nvhe/clock.c @@ -8,7 +8,12 @@ #include #include +#include +#include +static u32 timer_freq; + +#ifdef CONFIG_NVHE_EL2_TRACING static struct clock_data { struct { u32 mult; @@ -66,3 +71,27 @@ u64 trace_hyp_clock(void) return (u64)ns + clock->data[bank].epoch_ns; } +#endif /* CONFIG_NVHE_EL2_TRACING */ + +int hyp_clock_init(void) +{ + timer_freq = read_sysreg(cntfrq_el0); + /* + * KVM will not initialize if FW didn't set cntfrq_el0, that is already + * part of the boot protocol. + */ + if (!timer_freq) + return -ENODEV; + + /* Timer freq can't be larger than 1Ghz by spec. */ + if (timer_freq > NSEC_PER_SEC) + return -EINVAL; + + return 0; +} + +/* Return time in ns. */ +u64 hyp_clock_ns(void) +{ + return mul_u64_u32_div(__arch_counter_get_cntvct(), NSEC_PER_SEC, timer_freq); +} diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 75b00c323310..970c5cf342f5 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -320,6 +321,10 @@ void __noreturn __pkvm_init_finalise(void) if (ret) goto out; + ret = hyp_clock_init(); + if (ret) + goto out; + ret = fix_host_ownership(); if (ret) goto out; -- 2.55.0.141.g00534a21ce-goog