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 BB4133537D2; Mon, 13 Apr 2026 14:42:05 +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=1776091328; cv=none; b=nPAwZLE7vUwE+Mr3u3KygadLaObN2njq3x5jvIdyYfIVeyh3oJfjKWwLoWHoNeluuE97waBzdYJowFBGOOvyeWdCXZ56ddXMGULUZFDyb2abxHJBf5WLfq2vDXJik/s3YTiv4sZ1YSjsD1TiZ0Ao6eQpQimI1Mid4vaV6A/wxVo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776091328; c=relaxed/simple; bh=Vnrz228eSk/mptycnXQRjUy58RSHNsaULpU2FASTdWU=; h=Message-ID:Date:MIME-Version:Subject:Cc:References:From: In-Reply-To:Content-Type; b=Zx5eQpZmuh5Um7vC50lX+UV4g6FDjaVEr4DBbJXvovcXuY0p1O4H+qrHRkafPl5Y+x0D110kFXO798PRWpACtLbu8jPF3LZepjpmLIO22dR1x6U+IVdLx5mySK5PZk+pV7I9pJjLVg2u5DlNbJBE0MHn2sbDPb0hA7ZeTwvECSM= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Ox4XFWgT; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Ox4XFWgT" 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 72055357A; Mon, 13 Apr 2026 07:41:59 -0700 (PDT) Received: from [10.1.196.46] (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B13E63F641; Mon, 13 Apr 2026 07:42:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1776091325; bh=Vnrz228eSk/mptycnXQRjUy58RSHNsaULpU2FASTdWU=; h=Date:Subject:Cc:References:From:In-Reply-To:From; b=Ox4XFWgTjz8OIRvYE2TPsgObpjTSWquTbGbtfyBurAHNFusQmwooU6ij0WBXa7ssY GnGPNXrGAkuHQvNgAPIjjezUioQbP/LC8CiCugXqLSvDv2GCQUvKx5oWqo/z7e6M+5 Fm8LZpzkjKkkAhAny3/DQ/+SL7TkOWMlVPTepHMQ= Message-ID: Date: Mon, 13 Apr 2026 15:41:59 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Thunderbird Daily Subject: Re: [PATCH v6 00/40] arm_mpam: Add KVM/arm64 and resctrl glue code Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org References: <20260313144617.3420416-1-ben.horgan@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260313144617.3420416-1-ben.horgan@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/13/26 14:45, Ben Horgan wrote: > This version of the mpam missing pieces series sees a couple of things > dropped or hidden. Memory bandwith utilization with free-running counters > is dropped in preference of just always using 'mbm_event' mode (ABMC > emulation) which simplifies the code and allows for, in the future, > filtering by read/write traffic. So, for the interim, there is no memory > bandwidth utilization support. CDP is hidden behind config expert as > remount of resctrl fs could potentially lead to out of range PARTIDs being > used and the fix requires a change in fs/resctrl. The setting of MPAM2_EL2 > (for pkvm/nvhe) is dropped as too expensive a write for not much value. > > There are a couple of 'fixes' at the start of the series which address > problems in the base driver but are only user visible due to this series. > > Changelogs in patches > > Thanks for all the reviewing and testing so far. Just a bit more to get this > over the line. > > There is a small build conflict with the MPAM abmc precursors series [1], which > alters some of the resctrl arch hooks. I will shortly be posting a respin > of that too. > > [1] https://lore.kernel.org/lkml/20260225201905.3568624-1-ben.horgan@arm.com/ > > From James' cover letter: > > This is the missing piece to make MPAM usable resctrl in user-space. This has > shed its debugfs code and the read/write 'event configuration' for the monitors > to make the series smaller. > Thanks for all the help testing and reviewing. James has now sent a pull request to Catalin and he has picked it up. Pull request: https://lore.kernel.org/linux-arm-kernel/01f76011-f3c2-4dcb-b3bc-37c7d4de342e@arm.com/ branch in arm64: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/mpam Ben