From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 71EDA15749A for ; Fri, 3 May 2024 17:10:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714756228; cv=none; b=DoezOGGbcZhDuaVdTqEeot4JjsaR2XSKVE3lI0KoD88YxaMJPAjTB5754F65kdpESgvaTArBCVNPVx1asodWgdMlW/OI3qeYuELQbt5BN5rR1FnUOSwJNSess4mjuT3n9STPA4/0piwhq+BbCUoTGbzhIYwqLWqrB2iB878Hfbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714756228; c=relaxed/simple; bh=OK2458DTTcUD97r6Dol6JsWgt2qOtHUUfDftniW40Qo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UIfjmbV8jeNAlJ7f3DLcipwNCrcdoMZSl+bgibG6AAKM7tRA7qSYgiV68KKgkhU8KAJpYe5TAJKy6UU1zZBCfh5x5BlEHxr8rfOpWqHpx4tJ5Q9ux/a0QdgKAy0goiFVzhBUj9Il73HGbL0BcaTXge+GMe5f9Zmf5C5E6F2oChg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 9BCD713D5; Fri, 3 May 2024 10:10:49 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.34.156]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3ED0E3F793; Fri, 3 May 2024 10:10:18 -0700 (PDT) Date: Fri, 3 May 2024 18:10:14 +0100 From: Mark Rutland To: Liao Chang Cc: catalin.marinas@arm.com, will@kernel.org, maz@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, tglx@linutronix.de, ardb@kernel.org, broonie@kernel.org, anshuman.khandual@arm.com, miguel.luis@oracle.com, joey.gouly@arm.com, ryan.roberts@arm.com, jeremy.linton@arm.com, ericchancf@google.com, kristina.martsenko@arm.com, robh@kernel.org, scott@os.amperecomputing.com, songshuaishuai@tinylab.org, shijie@os.amperecomputing.com, akpm@linux-foundation.org, bhe@redhat.com, horms@kernel.org, mhiramat@kernel.org, rmk+kernel@armlinux.org.uk, shahuang@redhat.com, takakura@valinux.co.jp, dianders@chromium.org, swboyd@chromium.org, sumit.garg@linaro.org, frederic@kernel.org, reijiw@google.com, akihiko.odaki@daynix.com, ruanjinjie@huawei.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v3 0/8] Rework the DAIF mask, unmask and track API Message-ID: References: <20240415064758.3250209-1-liaochang1@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240415064758.3250209-1-liaochang1@huawei.com> Hi, On Mon, Apr 15, 2024 at 06:47:50AM +0000, Liao Chang wrote: > This patch series reworks the DAIF mask, unmask, and track API for the > upcoming FEAT_NMI extension added in Armv8.8. > > As platform and virtualization[1] supports for FEAT_NMI is emerging, and > Mark Brown's FEAT_NMI patch series[2] highlighted the need for clean up > the existing hacking style approach about DAIF management code before > adding NMI functionality, furthermore, we discover some subtle bugs > during 'perf' and 'ipi_backtrace' transition from PSEUDO_NMI to > FEAT_NMI, in summary, all of these emphasize the importance of rework. > > This series of reworking patches follows the suggestion from Mark > Rutland mentioned in Mark Brown's patchset. In summary, he think the > better way for DAIF manangement look likes as following: > > (a) Adding entry-specific helpers to manipulate abstract exception masks > covering DAIF + PMR + ALLINT. Those need unmask-at-entry and > mask-at-exit behaviour, and today only need to manage DAIF + PMR. > > It should be possible to do this ahead of ALLINT / NMI support. > > (b) Adding new "logical exception mask" helpers that treat DAIF + PMR + > ALLINT as separate elements. I've started looking at this in the series. There are some subtleties here, and I don't think the helpers in this series are quite right as-is. I will try to get back to you next week with a description of those; it'll take a short while to write that up correctly and clearly and I don't trust myself to rush that last thing on a Friday. Thanks, Mark. > > This patches cherry-pick a part of Mark Brown' FEAT_NMI series, in order > to pass compilation and basic testing, includes perf and ipi_backtrace. > > [1] https://lore.kernel.org/all/20240407081733.3231820-1-ruanjinjie@huawei.com/ > [2] https://lore.kernel.org/linux-arm-kernel/Y4sH5qX5bK9xfEBp@lpieralisi/ > > v3->v2: > 1. Squash two commits that address two minor issues into Mark Brown's > origin patch for detecting FEAT_NMI. > 2. Add one patch resolves the kprobe reenter panic while testing > FEAT_NMI on QEMU. > > v2->v1: > Add SoB tags following the origin author's SoBs. > > Liao Chang (5): > arm64: daifflags: Add logical exception masks covering DAIF + PMR + > ALLINT > arm64: Unify exception masking at entry and exit of exception > arm64: Deprecate old local_daif_{mask,save,restore} > irqchip/gic-v3: Improve the maintainability of NMI masking in GIC > driver > arm64: kprobe: Keep NMI maskabled while kprobe is stepping xol > > Mark Brown (3): > arm64/sysreg: Add definitions for immediate versions of MSR ALLINT > arm64/cpufeature: Detect PE support for FEAT_NMI > arm64/nmi: Add Kconfig for NMI > > arch/arm64/Kconfig | 17 ++ > arch/arm64/include/asm/cpufeature.h | 6 + > arch/arm64/include/asm/daifflags.h | 298 ++++++++++++++++++++++----- > arch/arm64/include/asm/nmi.h | 27 +++ > arch/arm64/include/asm/sysreg.h | 2 + > arch/arm64/include/uapi/asm/ptrace.h | 1 + > arch/arm64/kernel/acpi.c | 10 +- > arch/arm64/kernel/cpufeature.c | 58 +++++- > arch/arm64/kernel/debug-monitors.c | 7 +- > arch/arm64/kernel/entry-common.c | 96 +++++---- > arch/arm64/kernel/entry.S | 2 - > arch/arm64/kernel/hibernate.c | 6 +- > arch/arm64/kernel/irq.c | 2 +- > arch/arm64/kernel/machine_kexec.c | 2 +- > arch/arm64/kernel/probes/kprobes.c | 4 +- > arch/arm64/kernel/setup.c | 2 +- > arch/arm64/kernel/smp.c | 6 +- > arch/arm64/kernel/suspend.c | 6 +- > arch/arm64/kvm/hyp/vgic-v3-sr.c | 6 +- > arch/arm64/kvm/hyp/vhe/switch.c | 4 +- > arch/arm64/mm/mmu.c | 6 +- > arch/arm64/tools/cpucaps | 2 + > drivers/irqchip/irq-gic-v3.c | 6 +- > 23 files changed, 442 insertions(+), 134 deletions(-) > create mode 100644 arch/arm64/include/asm/nmi.h > > -- > 2.34.1 > >