From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69455143895 for ; Mon, 6 May 2024 12:12:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714997580; cv=none; b=mZuvXPHkmcUrV12mLsLmn6pw+glqOEncWp4VjGJYR6GKzlp90GiQPegx0Zq09yxsSbZLOTc7gyLRlk5j51cUAF3wO58xs+7nPSVgA4yktFdOpuH3YPkURn37825BmoeLxJQYwn+9I+gjnNVKem9mgOlU/WT8MR9PTsJnrFC+184= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714997580; c=relaxed/simple; bh=Iz5B8F7XltdwEMC2wpjkKK1FHOvCSMw2lG0kBy8i1wI=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=VPnCWle6VRnow0r6rlqn3zqu84C8TN3J5cS/lDMXvRcVO0H83TeJJ4ZRWp2dS9U9mErNqu5xkb8lrUg58pOxqgBKwwdpvyXGoSvafW5detoPTZJxKQr0R313v/v3C4CDd4gFlTUdNNnrjeMp8TPAgCv4KTUXKVTsbqldNI4UHms= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.255 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4VY0Zh2Pknz1RBXH; Mon, 6 May 2024 20:09:32 +0800 (CST) Received: from kwepemd200013.china.huawei.com (unknown [7.221.188.133]) by mail.maildlp.com (Postfix) with ESMTPS id 8E3A41800C7; Mon, 6 May 2024 20:12:49 +0800 (CST) Received: from [10.67.110.108] (10.67.110.108) by kwepemd200013.china.huawei.com (7.221.188.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Mon, 6 May 2024 20:12:46 +0800 Message-ID: Date: Mon, 6 May 2024 20:12:46 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH v3 0/8] Rework the DAIF mask, unmask and track API To: Mark Rutland CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , References: <20240415064758.3250209-1-liaochang1@huawei.com> From: "Liao, Chang" In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemd200013.china.huawei.com (7.221.188.133) 在 2024/5/4 1:10, Mark Rutland 写道: > 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. Hi，Mark Thanks for your feedback.I apprecaite your interest in this patch series and look forward to receiving additional comments from you and others in the community. I am pleased to inform you that the FEAT_NMI features has been successfully merged into the upstream QEMU codebase at the "master" branch recently. This allow for initial testing without requiring hardware support for FEAT_NMI. To ensure minimal regressions introduced by this patch series, i have done testing using perf top, hardlokup and ipi nmi for various configurations, including (1) no NMI (2) use CONFIG_PSEUDO_NMI (3) use CONFIG_ARM64_NMI. We encourage further discussion and feedback on the patch series. We are particularly interested in hearing from developers who might have experience with NMI handling or those using platforms with FEAT_NMI capabilities. Thank you. > >> >> 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 >> >> > -- BR Liao, Chang