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 C2AECCA5FC5 for ; Wed, 30 Sep 2026 13:39:30 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Vr6JqvYiKd4vRaGkCdc7ynSusqyoLMCPVRGC37iHFa8=; b=K2adjNA3oFIIn31gJ0VpFRCjjc JIze8eJGDeSwtGt1+FTPwWMj37pMf79d5SUDbZ847c2gilhxDv7NrhLCpJMmSzQpOTiJ7Gk4xFZFH A7bO3r0AoM3tKCIpsbodrkD26WdJA+P0S3zubx/135Y/qTqis5s7M0IsIiFwt9lyp1bhyeU0vpDsY dzdGdQa51wKJILcLzTnUaIAP8qRYSnTICd5vT0dn+4hdL9vZshOxzu52ZITElsAkASGgP/05FWjrG 8YBKZOrcBbD/OMR1TtXEUy7W+NFB7obHRzJh5AR2E41upZUQAo3Q7k49tL5yDUbvLCDdv8RBlWnCW OBp3i8Gg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBuWn-000000069qY-3Zxm; Wed, 30 Sep 2026 13:39:21 +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 1xBuWj-000000069oh-2vvJ for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2026 13:39:19 +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 08061497; Wed, 30 Sep 2026 06:39:12 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1B1893F86F; Wed, 30 Sep 2026 06:39:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790775555; bh=WrLZ5gfj597SIIguCgOUtqlPTHgYb9tcuWrI/gHAH10=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Pcj3sxhuzrhm1E/ig/tQbFU+vGp68EdZ3hS1A4ER37ixvE4v7iH8lKDH1EWxVDw4P q+VI/Tvjrv3VA4weqNAi0Sk4uHAMzZk+rQoW1zI+4kSSTimnPuEZWd4Op4GrayP4c0 6U0s8zjk3oI005UNqWKJnYD8xBQpRrTB5+UdNchM= Date: Wed, 30 Sep 2026 14:39:04 +0100 From: Catalin Marinas To: Suzuki K Poulose Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, maz@kernel.org, will@kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, tabba@google.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com Subject: Re: [PATCH v20 6/9] firmware: arm_rmm: Ensure the RMM has GPT entries for memory Message-ID: References: <20260929221623.1342076-1-suzuki.poulose@arm.com> <20260929221623.1342076-7-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260929221623.1342076-7-suzuki.poulose@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260930_063918_186768_DF87C2A2 X-CRM114-Status: GOOD ( 17.69 ) 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 On Tue, Sep 29, 2026 at 11:16:20PM +0100, Suzuki K Poulose wrote: > From: Steven Price > > The RMM maintains the state of all the granules in the system to make > sure that the host is abiding by the rules. This state can be maintained > at different granularity, per page (TRACKING_FINE) or per region > (TRACKING_COARSE or TRACKING_INTERMEDIATE). The region size depends on the > underlying "RMI_GRANULE_SIZE". For a "coarse"/"intermediate" region, > all pages in the region must be of the same state, this implies we need to > have "fine" tracking for DRAM, so that we can delegate individual pages. > > For now we only support a statically carved out memory for tracking > granules for the "fine" regions. This can be extended in the future to > allow modifying the tracking granularity and remove the need for a > static allocation by the firmware. > > Similarly, the firmware may create L0 GPT entries describing the total > address space. But if we change the "PAS" (Physical Address Space) of a > granule, then the firmware may need to create L1 tables to track the PAS > at a finer granularity. Linux therefore checks if the platform firmware > manages the PAR region. i.e., the firmware is in charge of managing the > L1 GPTs (creation and the required memory for the GPT tables - via static > carveouts) without host intervention. Support for dynamic GPT creation by > the host will be added later. > > If the firmware requires us to manage the tracking or GPT memory, > deactivate the RMM and reclaim any memory donated at RMM activation. > > Apply the same checks when hotplugged memory is brought online. > > Reviewed-by: Jonathan Cameron > Reviewed-by: Gavin Shan > Tested-by: Gavin Shan > Signed-off-by: Steven Price > Co-developed-by: Suzuki K Poulose > Signed-off-by: Suzuki K Poulose Reviewed-by: Catalin Marinas