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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96496C433EF for ; Sat, 16 Oct 2021 13:55:04 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 0549F611AF for ; Sat, 16 Oct 2021 13:55:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0549F611AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 84F6B4B168; Sat, 16 Oct 2021 09:55:03 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id g+NayzFyyPlp; Sat, 16 Oct 2021 09:54:59 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id EE23E4B11C; Sat, 16 Oct 2021 09:54:59 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C304C4B11F for ; Sat, 16 Oct 2021 09:54:58 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3klZFdJ9V95D for ; Sat, 16 Oct 2021 09:54:58 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id DE4BF4B119 for ; Sat, 16 Oct 2021 09:54:57 -0400 (EDT) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DB0B660698; Sat, 16 Oct 2021 13:54:56 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mbk9G-00HCTW-Ld; Sat, 16 Oct 2021 14:54:54 +0100 Date: Sat, 16 Oct 2021 14:54:54 +0100 Message-ID: <87a6j9ulap.wl-maz@kernel.org> From: Marc Zyngier To: James Morse Subject: Re: [RFC PATCH 0/7] arm64: mm: Prototype to allow drivers to request PBHA values In-Reply-To: <20211015161416.2196-1-james.morse@arm.com> References: <20211015161416.2196-1-james.morse@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: james.morse@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, catalin.marinas@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Hi James, On Fri, 15 Oct 2021 17:14:09 +0100, James Morse wrote: > > Hello! > > Do you have hardware that uses PBHA? If so, what does the SoC do in > response to which bits, and what workload needs that behaviour? > > This series is a start at trying to work out what linux needs to > support to makeuse of existing SoCs using PBHA. Thanks for starting this. I think one part that is missing here is the device side of things. How do these attributes get used by the SMMU, how do we convey them to the DMA layer, and what is the expected behaviour when we have SVA? Not having any guidance form the architecture means that we're walking on very thin ice... M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm