From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A5D19C88E50 for ; Mon, 14 Sep 2026 10:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=rzO7OTZ3YUgiMwjBwPcTW80BkR7oDR+DpiTI+i6tZBs=; b=c3mc+AXMuvJnv+tRy1NjrFGEd6 LKZT78W9Eo6JfcxvLRUec+wl2z4yWSScmjqYIoVu1idK8s0PTa1NqCgoPc+hRikbuqlu0LUuEY1Pn OGOhCVofB5WMgz3WCBj0/dIqji3/Wpto2cya6y0LRgb9yHEX0Zq6m1a68rrwTIxxROTk5xLevWPGV 84uDPfdWfzIAjjjZlmnlrmfB4tJPnG3jEDsJO1Lm4lqoBKXWqBswRJiKX7LGPTpOn35FRUhrRFRlG bEo7TfFRvf87+DkH45AxmqxNokC1S7lWSeJx9t/MR/9HcZEl6YICduS2Or3YN8Gkhwg7iwt7z9qpe ARY2kZ9A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x63oe-000000035HX-0bhz; Mon, 14 Sep 2026 10:21:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x63oZ-000000035FM-2ONQ for linux-arm-kernel@lists.infradead.org; Mon, 14 Sep 2026 10:21:32 +0000 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 3A4401570; Mon, 14 Sep 2026 03:21:24 -0700 (PDT) Received: from login2.euhpc2.arm.com (login2.euhpc2.arm.com [10.58.100.22]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B89C63F7B4; Mon, 14 Sep 2026 03:21:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789381287; bh=+30m5d0nV9U85GWjFukM3/Jqs/iDhIxpb7DbDj5gkGA=; h=From:To:Cc:Subject:Date:From; b=NkvE0U55EzpbvHv7eVD26JP+5jpRQUExa6E5Kys51dLGMgWtPf7aQ2YBBpDGe7dSk zmbHmzBXZQoFEQctRPSgQ+v1L3gJV8/JLYOJHLWAHJJ+byG+fn4T2NupYKqwZYxDLg hyb86muvgTF40t2+g3e6ikk9sFsjiQTmbm2ymUiE= From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, maz@kernel.org, lpieralisi@kernel.org, ruanjinjie@huawei.com, liaochang1@huawei.com Subject: [PATCH 00/38] arm64: Add support for FEAT_NMI Date: Mon, 14 Sep 2026 11:20:24 +0100 Message-Id: <20260914102102.68597-1-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260914_032131_704918_E899930B X-CRM114-Status: GOOD ( 22.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org FEAT_NMI provides an architected mechanism for supporting non-maskable interrupts (NMIs) and less-masked interrupts (LMIs). Since we already support pseudo-NMIs via priority masking, introducing another flavour of NMI on top of the existing infrastructure could easily become messy, making the code harder to follow and reason about. To avoid that, this series first makes room for the new NMI "tenant" by restructuring the existing exception masking logic (patches 01/38 - 15/38) The main idea is to separate the logical view of exception state from its hardware representation. To achieve this, we introduce logical exception contexts that can be mapped onto the corresponding hardware state. This naturally consolidates the hardware-specific handling into a small number of places, while allowing the rest of the code to operate purely in terms of logical exception contexts. Since this restructuring is non-trivial and carries a risk of subtle behavioural changes, the series adds extensive debug checks to verify that the hardware state always matches the expected logical state. With this restructuring in place, wiring FEAT_NMI into the new framework becomes much more manageable (pathes 16/38 - 32/38). GIC support for NMI is build on top (pathes 33/38 - 38/38) This work would not have been possible without the contributions of Ada Couprie Diaz, Mark Brown, and Lorenzo Pieralisi - please credit them for everything that works well. Any remaining bugs or issues are entirely my own. Although I droped RFC tag, I'd still appreciate feedback on the overall approach. Most of the testing has been done on QEMU, Fast Model and pre-silicon environment, so the series definitely benefit from extensive testing on real hardware (without NMI, with pseudo-NMI, and with FEAT_NMI). Changelog RFC v2 -> v1 - Rebased on v7.3-rc3. - Dropped RFC tag, have not received objections, at the same time got support from Jinjie - Dropped prerequisite patches already present in the newer base - Added logic to reject probing/stepping over ALLINT - Moved addition of arm64_debug_exc_context() in separate patch - Reworked debug logic for validating direction of exception transition - Split support for NMI in GICv5 in 3 separate patches - Added review tags RFC v1 -> RFC v2 - Rebased on v7.2-rc5. - Improved commit descriptions. - Split some patches into smaller ones. - Added a graceful fallback for IPI requests when FEAT_NMI is supported by the CPU but unsupported by the interrupt controller. - Split the GICv3 preparation from the FEAT_GICv3_NMI implementation. - Added NMI support to GICv5, primarily as an illustration of the implementation, although it also happens to work on Fast Model. - Added review tags only to unchanged patches. Review tags were intentionally dropped from modified patches to reflect those changes and encourage re-review. RFC v1: https://lore.kernel.org/linux-arm-kernel/20260709121333.23507-1-vladimir.murzin@arm.com/ RFC v2: https://lore.kernel.org/linux-arm-kernel/20260727163453.7969-1-vladimir.murzin@arm.com/ Thanks! Vladimir Ada Couprie Diaz (15): arm64: irqflags: Introduce arm64-specific irqflags type arm64: irqflags: save and use both DAIF and PMR arm64: interrupts: Add common exception state helpers arm64: entry: Introduce entry specific exception masking helpers arm64: entry: replace DAIF helpers with entry helpers arm64: interrupts: Introduce exception masking save/restore helpers arm64: interrupts: introduce a helper for GIC priority initialization arm64: replace local_daif helpers arm64: cpuidle: use new helpers to bypass interrupt priority masking arm64: remove daifflags.h arm64: gicv3: remove GIC_PRIO_PSR_I_SET arm64: ptrace: Add PSR_ALLINT_BIT arm64: cpufeature: Detect PE support for FEAT_NMI arm64: nmi: Manage masking for superpriority interrupts arm64: irq: Report FEAT_NMI masking local IRQs Lorenzo Pieralisi (2): irqchip/gic-v3: Rename nmi to pseudo_nmi irqchip/gic-v3: Implement FEAT_GICv3_NMI support Mark Brown (5): arm64: booting: Document boot requirements for FEAT_NMI arm64: sysreg: Add definitions for immediate versions of MSR ALLINT arm64: idreg: Add an override for FEAT_NMI arm64: nmi: Add handling of superpriority interrupts as NMIs arm64: nmi: Add Kconfig for NMI Vladimir Murzin (16): arm64: process: Lift check for exception state to generic infrastructure arm64: cpufeature: Remove system_has_prio_mask_debugging() arm64: irqflags: Switch to CONFIG_DEBUG_IRQFLAGS arm64: Kconfig: Remove CONFIG_ARM64_DEBUG_PRIORITY_MASKING efi/runtime-wrappers: Permit architectures to override IRQ flags checks arm64/efi: Implement override for IRQ flags checks arm64: probes: Reject stepping over ALLINT arm64: suspend: Always initialise PSTATE.ALLINT arm64/efi: Add ALLINT to IRQ flags checks arm64: kprobes: Disable NMIs arm64: smp: Abstract SGI and LPI operations arm64: smp: Fall back to IRQ when IPI NMI request fails arm64: smp: Add NMI support for LPI-backed IPIs genirq: Trust local irqchip when considering IRQ for NMI genirq: Do not call add_interrupt_randomness() in NMI context irqchip/gic-v5: Add NMI support Documentation/arch/arm64/booting.rst | 6 + arch/arm64/Kconfig | 29 +- arch/arm64/include/asm/assembler.h | 20 +- arch/arm64/include/asm/cpucaps.h | 2 + arch/arm64/include/asm/cpufeature.h | 14 +- arch/arm64/include/asm/cpuidle.h | 18 +- arch/arm64/include/asm/daifflags.h | 144 -------- arch/arm64/include/asm/efi.h | 42 ++- arch/arm64/include/asm/entry-common.h | 8 +- arch/arm64/include/asm/insn.h | 1 + .../include/asm/interrupts/common_flags.h | 256 +++++++++++++ arch/arm64/include/asm/interrupts/entry.h | 102 ++++++ arch/arm64/include/asm/interrupts/masking.h | 166 +++++++++ arch/arm64/include/asm/irqflags.h | 150 ++++---- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/include/asm/mmu_context.h | 1 - arch/arm64/include/asm/ptrace.h | 25 +- arch/arm64/include/asm/sysreg.h | 2 + arch/arm64/include/uapi/asm/ptrace.h | 1 + arch/arm64/kernel/acpi.c | 15 +- arch/arm64/kernel/cpufeature.c | 68 +++- arch/arm64/kernel/debug-monitors.c | 1 - arch/arm64/kernel/entry-common.c | 335 +++++++++++++----- arch/arm64/kernel/entry.S | 14 +- arch/arm64/kernel/hibernate.c | 14 +- arch/arm64/kernel/irq.c | 45 ++- arch/arm64/kernel/machine_kexec.c | 4 +- arch/arm64/kernel/pi/idreg-override.c | 1 + arch/arm64/kernel/probes/decode-insn.c | 11 +- arch/arm64/kernel/probes/kprobes.c | 24 +- arch/arm64/kernel/process.c | 24 +- arch/arm64/kernel/setup.c | 4 +- arch/arm64/kernel/signal.c | 1 - arch/arm64/kernel/smp.c | 216 +++++++---- arch/arm64/kernel/suspend.c | 14 +- arch/arm64/kernel/traps.c | 1 - arch/arm64/kvm/hyp/nvhe/switch.c | 2 +- arch/arm64/kvm/hyp/vgic-v3-sr.c | 7 +- arch/arm64/kvm/hyp/vhe/switch.c | 14 +- arch/arm64/mm/fault.c | 1 - arch/arm64/mm/mmu.c | 7 +- arch/arm64/tools/cpucaps | 2 + drivers/firmware/efi/runtime-wrappers.c | 32 +- drivers/irqchip/irq-gic-v3.c | 132 ++++++- drivers/irqchip/irq-gic-v5.c | 244 ++++++++++++- include/linux/irq.h | 2 +- include/linux/irqchip/arm-gic-v3-prio.h | 8 - include/linux/irqchip/arm-gic-v3.h | 4 + kernel/irq/handle.c | 3 +- kernel/irq/manage.c | 5 - 50 files changed, 1661 insertions(+), 582 deletions(-) delete mode 100644 arch/arm64/include/asm/daifflags.h create mode 100644 arch/arm64/include/asm/interrupts/common_flags.h create mode 100644 arch/arm64/include/asm/interrupts/entry.h create mode 100644 arch/arm64/include/asm/interrupts/masking.h -- 2.34.1