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 C125944A71E 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=DkXH4KDYQAMdiIsCRU1UfOMzOJIqbb/Mr4cl9kQG1xQnTyizHZeO8aWgowvpeXVcpPLwKS9OTkrYqjqgVmCsLCQ/+S+du0dK3KiH5pWtIEfIKSkT8y7Fi95BmkkvuMuub8pA6gwUqkLZP7B+bDyQl8PzRZPp7t9fFM25tXWlRUU= 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=SraMscVO; 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="SraMscVO" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-493ba771d1bso20790815e9.2 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=vger.kernel.org; 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=SraMscVOoAd1w8aKHKa2jtiScu0h502C/ylEe2qsMEbmamfiaJt4T86/2pN0MxAIYX V2XsIrpebCuiLOo7WIMGOGx/rcX67i5GbGzDRXErGKsyGnRiOLB4ECmKBJfoc3uxH8A3 f/cQ0f7k9VF3NrVdkAxFQUuScb07toAbhjchPEQJq9T4Dx0mptGBegb02+eDd9gcO3FO aHBa4NlOB6893W06EqL7ZsbGhhhFz+hqeHmCj9u0JHGCBoNP+WpbZ/l+BMomz6178lre yZO1ygQKudPw3tLvmzALYflGN0ZZIkEgiDHekEj9ck60VVpp/ooVISBXrKp4V0NYyuBp rg+w== 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=a5wNKMdonYU/7kgsUvl3nQSbXs36eoNkZgDrxBMwTBryOO9tBDIsrvrhZhmbPXC4jg iz/Uh0nvo8RIJcDegUom2IXJpRTo3OgdzDAhTC6V+hs38JxCo3zMyFRtRlFcuTBKJOeu R8ZgF2PfbuuGV5teJmIWTwW28/opH7Zk68kAiAg/5OyKxDXTSWCMLQ0CZYTo+QsesUX8 z2KZwddp0n4t3LYYOz/CIQ3dvd8oeFZgvVRSLmN3HizjbRzSE/Emt73yidN3IbAOJ4jH GTSwFXb3RJI5OyjIuUzlpac31erFu1vfCpfWF9AyjDI1f/N02MPVxr8naS1GuBm2TBbR Gelg== X-Forwarded-Encrypted: i=1; AHgh+RqCYDXHFanJPzqyS45ytxyIcjfcFhU8uGAfjlWcWjTG7CCGiFB9UajcEwrAu5TjXXQC+lTlxK+G1ZuYlsQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yzs38ns8m4PrdVVPpEYYrs0rf3W3OjDzrFdNwPyhzVzv06yeQEi ldgaSnBwD++HrF/2xLZUgpbttb0u1No19P7qRWcp/IvbUTa7HcxM3PuGtDzDAf9zY3DyKsmbkYF MrYskj6s0JqXXmg== 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: linux-kernel@vger.kernel.org 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