Received: by 2002:a05:6a10:a852:0:0:0:0 with SMTP id d18csp3419338pxy; Tue, 4 May 2021 01:31:43 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxF7DGjXyPyJExNpOACGxemJxOnlIpFT4KxDTCGm75dm/anWXfYj+nxFId2RD9kXXpMMNzz X-Received: by 2002:a17:907:10cb:: with SMTP id rv11mr20721154ejb.379.1620117103632; Tue, 04 May 2021 01:31:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1620117103; cv=none; d=google.com; s=arc-20160816; b=1DRNjsQpO1cGp4lLpfp2u27mpZJKhvIywVv85p3M/VUrk3HG8yblbwS0/H1Osfx3Bq VkkUWMNjE0CWRepLq9FXmFD5dDVHqUpMoqFt6jehk8pjmINBnih9TLGkWHeXknS0g4YE xuFGo6ceTuBBYQGb4ugLv8fW+EXDNRVCxyY7Iio849TR/bEwHtZ3iEXkrqR8/Kov36Ic T2U8FmD5dy2f5fokMmZqAKaqcVr4c7ETwalTE6+Dsfqtpy7G3CCxKxiiy0KXXrnUM1Hm eJUtbRwP4DBva2UMMVPmSojqphxBnsax4uJRKn5/x9Jovx785cCzbUW8KwMJ9ifEb7hM H1kA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=k1H6gR5bqpHyFM9a3JEHzunn9rfwS0P9q2H6xWtuNMk=; b=V8AtPrlj8VJcWsQgOH7FyUmOFXYHWJo22vSXxg9e4k9BDElHhTbqTVn9zka5UCWMYw EvHplFGTS0zUxcpPtmCbXYPJ3pnXweUYlsLgKibJVqev4i0iu/Fv03CuIssyWqHkTPUB s1f1EM3kOpCM9Bu5I84xtQRUdz8TNLviBuXsXBF7/TmIIxMiqGbeZQ7RaSbAtxgAadvo FPrvlB3mZ9re0x3MQsWA+yeHiLwA82KGctjfylBARjKfe7srzjRyDyAOv2jQI+deybJ1 +VfIaV9IrJH08So+NPwKhOfdPxPvJ4iejGO94sS9G4NZ0e6dsjoWBFcPGe7JK5jEWEnN XHqA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=MFnRDdSd; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id f17si11197390edr.441.2021.05.04.01.31.19; Tue, 04 May 2021 01:31:43 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=MFnRDdSd; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230097AbhEDIbG (ORCPT + 99 others); Tue, 4 May 2021 04:31:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:36178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229920AbhEDIbF (ORCPT ); Tue, 4 May 2021 04:31:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1CEF2613BA; Tue, 4 May 2021 08:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620117011; bh=SA0MPq08S4sIbEu0S/YkhVbAPJQkRS5WeyPcEthMjx8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MFnRDdSddwFqD0o+BFnn3MH3YKem6HT//4u8RH8EXkPAcQT9SkeWZNklQFzo7wOQB HXvNwJWmMvA1IcwoMACcnxUpimVDq6op2UIEj0NHPacUaNQpBw4mLOKutdV8VHhdzQ tbi/EeK3qbxUA7dPh3UIZZ41LtqvbZG/8B4D6uoz253eQgtYCUPk0Er3JjRnbL04eL H4oTHVChbT7vJKYa+ihaC6dHWLnbIyTxgnUu3h/aBLrSSszNynVwXEeUB1DT7sLR5w jPgVoOqjKc10n+KxOyuvx83dQRxSLi4+E7XR72yx+Z7H4KUyYX+ZtQgT5vCjlgR+J7 RPZjLwKCg+RsA== Date: Tue, 4 May 2021 09:30:05 +0100 From: Will Deacon To: Vikram Sethi Cc: Alex Williamson , Mark Kettenis , Marc Zyngier , Shanker Donthineni , "catalin.marinas@arm.com" , "christoffer.dall@arm.com" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , Jason Sequeira Subject: Re: [RFC 1/2] vfio/pci: keep the prefetchable attribute of a BAR region in VMA Message-ID: <20210504083005.GA12290@willie-the-truck> References: <1edb2c4e-23f0-5730-245b-fc6d289951e1@nvidia.com> <878s4zokll.wl-maz@kernel.org> <87eeeqvm1d.wl-maz@kernel.org> <87bl9sunnw.wl-maz@kernel.org> <20210503084432.75e0126d@x1.home.shazbot.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 03, 2021 at 10:03:59PM +0000, Vikram Sethi wrote: > Will/Catalin, perhaps you could explain your thought process on why you chose > Normal NC for ioremap_wc on the armv8 linux port instead of Device GRE or other > Device Gxx. I think a combination of: compatibility with 32-bit Arm, the need to support unaligned accesses and the potential for higher performance. Furthermore, ioremap() already gives you a Device memory type, and we're tight on MAIR space. Will