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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74032C433F5 for ; Tue, 28 Aug 2018 15:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24F352084A for ; Tue, 28 Aug 2018 15:51:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24F352084A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727230AbeH1ToF (ORCPT ); Tue, 28 Aug 2018 15:44:05 -0400 Received: from foss.arm.com ([217.140.101.70]:40896 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbeH1ToF (ORCPT ); Tue, 28 Aug 2018 15:44:05 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9D80F80D; Tue, 28 Aug 2018 08:51:48 -0700 (PDT) Received: from e112298-lin.Emea.Arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AE5433F557; Tue, 28 Aug 2018 08:51:46 -0700 (PDT) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, mark.rutland@arm.com, christoffer.dall@arm.com, james.morse@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, Julien Thierry Subject: [PATCH v5 00/27] arm64: provide pseudo NMI with GICv3 Date: Tue, 28 Aug 2018 16:51:10 +0100 Message-Id: <1535471497-38854-1-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This series is a continuation of the work started by Daniel [1]. The goal is to use GICv3 interrupt priorities to simulate an NMI. The patches depend on the core API for NMIs patches [2]. To achieve this, set two priorities, one for standard interrupts and another, higher priority, for NMIs. Whenever we want to disable interrupts, we mask the standard priority instead so NMIs can still be raised. Some corner cases though still require to actually mask all interrupts effectively disabling the NMI. Daniel Thompson ran some benchmarks [3] on the previous version showing a small (<1%) performance drop when using interrupt priorities. Currently, only PPIs and SPIs can be set as NMIs. IPIs being currently hardcoded IRQ numbers, there isn't a generic interface to set SGIs as NMI for now. LPIs being controlled by the ITS cannot be delivered as NMI. When an NMI is active on a CPU, no other NMI can be triggered on the CPU. Requirements to use this: - Have GICv3 - SCR_EL3.FIQ is set to 1 when linux runs or have single security state - Select Kernel Feature -> Use ICC system registers for IRQ masking * Patches 1 to 3 aim at applying some alternatives early in the boot process. * Patches 4 to 7 ensure the logic of daifflags remains valid after arch_local_irq flags use ICC_PMR_EL1. * Patches 8 and 9 clean up GIC current priority definition to make it easier to introduce a new priority * Patches 10 to 16 prepare arch code for the use of priorities, saving and restoring ICC_PMR_EL1 appropriately * Patches 17 to 20 add the support to GICv3 driver to use priority masking if required by the architecture * Patches 21 to 23 make arm64 code use ICC_PMR_EL1 to enable/disable interrupts, leaving PSR.I as often as possible * Patches 24 to 27 add the support for NMIs to GICv3 driver Changes since V4[4]: * Rebased to v4.19-rc1 * Adapted GIC driver to the core NMI API * Added option to disable priority masking on command line * Added Daniel's Tested-by on patches related replacing PSR.I toggling with PMR masking * Fix scope matching for alternative features. * Spotted some more places using PSR.I or daif and replaced with generic interrupt functions Changes since V3[5]: * Big refactoring. As suggested by Marc Z., some of the bigger patches needed to be split into smaller one. * Try to reduce the amount of #ifdef for the new feature by introducing an individual cpufeature for priority masking * Do not track which alternatives have been applied (was a bit dodgy anyway), and use an alternative for VHE cpu_enable callback * Fix a build failure with arm by adding the correct RPR accessors * Added Suggested-by tags for changes from comming or inspired by Daniel's series. Do let me know if you feel I missed something and am not giving you due credit. Changes since V2[6]: * Series rebase to v4.17-rc6 * Adapt pathces 1 and 2 to the rework of cpufeatures framework * Use the group0 detection scheme in the GICv3 driver to identify the priority view, and drop the use of a fake interrupt * Add the case for a GIC configured in a single security state * Use local_daif_restore instead of local_irq_enable the first time we enable interrupts after a bp hardening in the handling of a kernel entry. Otherwise PRS.I remains set... Changes since V1[7]: * Series rebased to v4.15-rc8. * Check for arm64_early_features in this_cpu_has_cap (spotted by Suzuki). * Fix issue where debug exception were not masked when enabling debug in mdscr_el1. Changes since RFC[8]: * The series was rebased to v4.15-rc2 which implied some changes mainly related to the work on exception entries and daif flags by James Morse. - The first patch in the previous series was dropped because no longer applicable. - With the semantics James introduced of "inheriting" daif flags, handling of PMR on exception entry is simplified as PMR is not altered by taking an exception and already inherited from previous state. - James pointed out that taking a PseudoNMI before reading the FAR_EL1 register should not be allowed as per the TRM (D10.2.29): "FAR_EL1 is made UNKNOWN on an exception return from EL1." So in this submission PSR.I bit is cleared only after FAR_EL1 is read. * For KVM, only deal with PMR unmasking/restoring in common code, and VHE specific code makes sure PSR.I bit is set when necessary. * When detecting the GIC priority view (patch 5), wait for an actual interrupt instead of trying only once. [1] http://www.spinics.net/lists/arm-kernel/msg525077.html [2] https://lkml.org/lkml/2018/8/28/661 [3] https://lkml.org/lkml/2018/7/20/803 [4] https://lkml.org/lkml/2018/7/24/321 [5] https://lkml.org/lkml/2018/5/21/276 [6] https://lkml.org/lkml/2018/1/17/335 [7] https://www.spinics.net/lists/arm-kernel/msg620763.html [8] https://www.spinics.net/lists/arm-kernel/msg610736.html Cheers, Julien --> Daniel Thompson (1): arm64: alternative: Apply alternatives early in boot process Julien Thierry (26): arm64: cpufeature: Set SYSREG_GIC_CPUIF as a boot system feature arm64: cpufeature: Use alternatives for VHE cpu_enable arm64: daifflags: Use irqflags functions for daifflags arm64: Use daifflag_restore after bp_hardening arm64: Delay daif masking for user return arm64: xen: Use existing helper to check interrupt status irqchip/gic: Unify GIC priority definitions irqchip/gic: Lower priority of GIC interrupts arm64: cpufeature: Add cpufeature for IRQ priority masking arm64: Make PMR part of task context arm64: Unmask PMR before going idle arm/arm64: gic-v3: Add helper functions to manage IRQ priorities arm64: kvm: Unmask PMR before entering guest arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking arm64: daifflags: Include PMR in daifflags restore operations irqchip/gic-v3: Factor group0 detection into functions irqchip/gic-v3: Do not overwrite PMR value irqchip/gic-v3: Remove acknowledge loop irqchip/gic-v3: Switch to PMR masking after IRQ acknowledge arm64: Switch to PMR masking when starting CPUs arm64: Add build option for IRQ masking via priority arm64: Handle serror in NMI context irqchip/gic-v3: Detect current view of GIC priorities irqchip/gic-v3: Add base support for pseudo-NMI irqchip/gic: Add functions to access irq priorities irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI Documentation/admin-guide/kernel-parameters.txt | 3 + Documentation/arm64/booting.txt | 5 + arch/arm/include/asm/arch_gicv3.h | 33 +++ arch/arm64/Kconfig | 15 ++ arch/arm64/include/asm/alternative.h | 3 +- arch/arm64/include/asm/arch_gicv3.h | 33 +++ arch/arm64/include/asm/assembler.h | 17 +- arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 2 + arch/arm64/include/asm/daifflags.h | 29 ++- arch/arm64/include/asm/efi.h | 3 +- arch/arm64/include/asm/irqflags.h | 100 +++++++-- arch/arm64/include/asm/kvm_host.h | 12 + arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/ptrace.h | 13 +- arch/arm64/include/asm/xen/events.h | 2 +- arch/arm64/kernel/alternative.c | 28 ++- arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kernel/cpufeature.c | 51 ++++- arch/arm64/kernel/entry.S | 63 +++++- arch/arm64/kernel/head.S | 35 +++ arch/arm64/kernel/process.c | 2 + arch/arm64/kernel/smp.c | 12 + arch/arm64/kernel/traps.c | 8 +- arch/arm64/kvm/hyp/switch.c | 17 ++ arch/arm64/mm/fault.c | 5 +- arch/arm64/mm/proc.S | 18 ++ drivers/irqchip/irq-gic-common.c | 10 + drivers/irqchip/irq-gic-common.h | 2 + drivers/irqchip/irq-gic-v3-its.c | 2 +- drivers/irqchip/irq-gic-v3.c | 279 +++++++++++++++++++----- include/linux/irqchip/arm-gic-common.h | 6 + include/linux/irqchip/arm-gic.h | 5 - 33 files changed, 699 insertions(+), 119 deletions(-) -- 1.9.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: julien.thierry@arm.com (Julien Thierry) Date: Tue, 28 Aug 2018 16:51:10 +0100 Subject: [PATCH v5 00/27] arm64: provide pseudo NMI with GICv3 Message-ID: <1535471497-38854-1-git-send-email-julien.thierry@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, This series is a continuation of the work started by Daniel [1]. The goal is to use GICv3 interrupt priorities to simulate an NMI. The patches depend on the core API for NMIs patches [2]. To achieve this, set two priorities, one for standard interrupts and another, higher priority, for NMIs. Whenever we want to disable interrupts, we mask the standard priority instead so NMIs can still be raised. Some corner cases though still require to actually mask all interrupts effectively disabling the NMI. Daniel Thompson ran some benchmarks [3] on the previous version showing a small (<1%) performance drop when using interrupt priorities. Currently, only PPIs and SPIs can be set as NMIs. IPIs being currently hardcoded IRQ numbers, there isn't a generic interface to set SGIs as NMI for now. LPIs being controlled by the ITS cannot be delivered as NMI. When an NMI is active on a CPU, no other NMI can be triggered on the CPU. Requirements to use this: - Have GICv3 - SCR_EL3.FIQ is set to 1 when linux runs or have single security state - Select Kernel Feature -> Use ICC system registers for IRQ masking * Patches 1 to 3 aim at applying some alternatives early in the boot process. * Patches 4 to 7 ensure the logic of daifflags remains valid after arch_local_irq flags use ICC_PMR_EL1. * Patches 8 and 9 clean up GIC current priority definition to make it easier to introduce a new priority * Patches 10 to 16 prepare arch code for the use of priorities, saving and restoring ICC_PMR_EL1 appropriately * Patches 17 to 20 add the support to GICv3 driver to use priority masking if required by the architecture * Patches 21 to 23 make arm64 code use ICC_PMR_EL1 to enable/disable interrupts, leaving PSR.I as often as possible * Patches 24 to 27 add the support for NMIs to GICv3 driver Changes since V4[4]: * Rebased to v4.19-rc1 * Adapted GIC driver to the core NMI API * Added option to disable priority masking on command line * Added Daniel's Tested-by on patches related replacing PSR.I toggling with PMR masking * Fix scope matching for alternative features. * Spotted some more places using PSR.I or daif and replaced with generic interrupt functions Changes since V3[5]: * Big refactoring. As suggested by Marc Z., some of the bigger patches needed to be split into smaller one. * Try to reduce the amount of #ifdef for the new feature by introducing an individual cpufeature for priority masking * Do not track which alternatives have been applied (was a bit dodgy anyway), and use an alternative for VHE cpu_enable callback * Fix a build failure with arm by adding the correct RPR accessors * Added Suggested-by tags for changes from comming or inspired by Daniel's series. Do let me know if you feel I missed something and am not giving you due credit. Changes since V2[6]: * Series rebase to v4.17-rc6 * Adapt pathces 1 and 2 to the rework of cpufeatures framework * Use the group0 detection scheme in the GICv3 driver to identify the priority view, and drop the use of a fake interrupt * Add the case for a GIC configured in a single security state * Use local_daif_restore instead of local_irq_enable the first time we enable interrupts after a bp hardening in the handling of a kernel entry. Otherwise PRS.I remains set... Changes since V1[7]: * Series rebased to v4.15-rc8. * Check for arm64_early_features in this_cpu_has_cap (spotted by Suzuki). * Fix issue where debug exception were not masked when enabling debug in mdscr_el1. Changes since RFC[8]: * The series was rebased to v4.15-rc2 which implied some changes mainly related to the work on exception entries and daif flags by James Morse. - The first patch in the previous series was dropped because no longer applicable. - With the semantics James introduced of "inheriting" daif flags, handling of PMR on exception entry is simplified as PMR is not altered by taking an exception and already inherited from previous state. - James pointed out that taking a PseudoNMI before reading the FAR_EL1 register should not be allowed as per the TRM (D10.2.29): "FAR_EL1 is made UNKNOWN on an exception return from EL1." So in this submission PSR.I bit is cleared only after FAR_EL1 is read. * For KVM, only deal with PMR unmasking/restoring in common code, and VHE specific code makes sure PSR.I bit is set when necessary. * When detecting the GIC priority view (patch 5), wait for an actual interrupt instead of trying only once. [1] http://www.spinics.net/lists/arm-kernel/msg525077.html [2] https://lkml.org/lkml/2018/8/28/661 [3] https://lkml.org/lkml/2018/7/20/803 [4] https://lkml.org/lkml/2018/7/24/321 [5] https://lkml.org/lkml/2018/5/21/276 [6] https://lkml.org/lkml/2018/1/17/335 [7] https://www.spinics.net/lists/arm-kernel/msg620763.html [8] https://www.spinics.net/lists/arm-kernel/msg610736.html Cheers, Julien --> Daniel Thompson (1): arm64: alternative: Apply alternatives early in boot process Julien Thierry (26): arm64: cpufeature: Set SYSREG_GIC_CPUIF as a boot system feature arm64: cpufeature: Use alternatives for VHE cpu_enable arm64: daifflags: Use irqflags functions for daifflags arm64: Use daifflag_restore after bp_hardening arm64: Delay daif masking for user return arm64: xen: Use existing helper to check interrupt status irqchip/gic: Unify GIC priority definitions irqchip/gic: Lower priority of GIC interrupts arm64: cpufeature: Add cpufeature for IRQ priority masking arm64: Make PMR part of task context arm64: Unmask PMR before going idle arm/arm64: gic-v3: Add helper functions to manage IRQ priorities arm64: kvm: Unmask PMR before entering guest arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking arm64: daifflags: Include PMR in daifflags restore operations irqchip/gic-v3: Factor group0 detection into functions irqchip/gic-v3: Do not overwrite PMR value irqchip/gic-v3: Remove acknowledge loop irqchip/gic-v3: Switch to PMR masking after IRQ acknowledge arm64: Switch to PMR masking when starting CPUs arm64: Add build option for IRQ masking via priority arm64: Handle serror in NMI context irqchip/gic-v3: Detect current view of GIC priorities irqchip/gic-v3: Add base support for pseudo-NMI irqchip/gic: Add functions to access irq priorities irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI Documentation/admin-guide/kernel-parameters.txt | 3 + Documentation/arm64/booting.txt | 5 + arch/arm/include/asm/arch_gicv3.h | 33 +++ arch/arm64/Kconfig | 15 ++ arch/arm64/include/asm/alternative.h | 3 +- arch/arm64/include/asm/arch_gicv3.h | 33 +++ arch/arm64/include/asm/assembler.h | 17 +- arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 2 + arch/arm64/include/asm/daifflags.h | 29 ++- arch/arm64/include/asm/efi.h | 3 +- arch/arm64/include/asm/irqflags.h | 100 +++++++-- arch/arm64/include/asm/kvm_host.h | 12 + arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/ptrace.h | 13 +- arch/arm64/include/asm/xen/events.h | 2 +- arch/arm64/kernel/alternative.c | 28 ++- arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kernel/cpufeature.c | 51 ++++- arch/arm64/kernel/entry.S | 63 +++++- arch/arm64/kernel/head.S | 35 +++ arch/arm64/kernel/process.c | 2 + arch/arm64/kernel/smp.c | 12 + arch/arm64/kernel/traps.c | 8 +- arch/arm64/kvm/hyp/switch.c | 17 ++ arch/arm64/mm/fault.c | 5 +- arch/arm64/mm/proc.S | 18 ++ drivers/irqchip/irq-gic-common.c | 10 + drivers/irqchip/irq-gic-common.h | 2 + drivers/irqchip/irq-gic-v3-its.c | 2 +- drivers/irqchip/irq-gic-v3.c | 279 +++++++++++++++++++----- include/linux/irqchip/arm-gic-common.h | 6 + include/linux/irqchip/arm-gic.h | 5 - 33 files changed, 699 insertions(+), 119 deletions(-) -- 1.9.1