From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1AE291A08C5; Tue, 10 Dec 2024 14:45:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733841910; cv=none; b=nIugwsT2FIWdCZow8sR7NFkYdcTNHI9g1tyRa+xnT8lWlVKRupcJgnOOi/ECrO6HVbUfRqnlnCWY2Ql0vuukhkXZt8/DIANWLH1hzRm/Zis4RECHrO1KeqPx9m8/rC5kXaFr/QVTa0tvcNY1bILlo2ECfAFMvXfIJQxihM2P3A8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733841910; c=relaxed/simple; bh=AH/pCnpbozjvR0gxiFQyIf+LtIXL5IUei0afkSAEeHk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=phkU3ZUVUfox/7pNlsaTdpm+87WtTx+W2RrF8Cyaq88YhHlea2ZNw1cUSdn4GIsUMFpTkBoNYzd4doKo2v+WZztjz+W5QYvgUNnpR8DnTnvRSOF5BMWD33lONf9O5yAVjlBZFpyerAArrbzS6s1fUYDIXST9dhMBR4IgpccCwlg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B804BC4CED6; Tue, 10 Dec 2024 14:45:03 +0000 (UTC) Date: Tue, 10 Dec 2024 14:45:01 +0000 From: Catalin Marinas To: Jason Gunthorpe Cc: Will Deacon , ankita@nvidia.com, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, ryan.roberts@arm.com, shahuang@redhat.com, lpieralisi@kernel.org, aniketa@nvidia.com, cjia@nvidia.com, kwankhede@nvidia.com, targupta@nvidia.com, vsethi@nvidia.com, acurrid@nvidia.com, apopple@nvidia.com, jhubbard@nvidia.com, danw@nvidia.com, zhiw@nvidia.com, mochs@nvidia.com, udhoke@nvidia.com, dnigam@nvidia.com, alex.williamson@redhat.com, sebastianene@google.com, coltonlewis@google.com, kevin.tian@intel.com, yi.l.liu@intel.com, ardb@kernel.org, akpm@linux-foundation.org, gshan@redhat.com, linux-mm@kvack.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 0/1] KVM: arm64: Map GPU memory with no struct pages Message-ID: References: <20241118131958.4609-1-ankita@nvidia.com> <20241210140739.GC15607@willie-the-truck> <20241210141806.GI2347147@nvidia.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241210141806.GI2347147@nvidia.com> On Tue, Dec 10, 2024 at 10:18:06AM -0400, Jason Gunthorpe wrote: > On Tue, Dec 10, 2024 at 02:07:40PM +0000, Will Deacon wrote: > > On Mon, Nov 18, 2024 at 01:19:57PM +0000, ankita@nvidia.com wrote: > > > The changes are heavily influenced by the insightful discussions between > > > Catalin Marinas and Jason Gunthorpe [1] on v1. Many thanks for their > > > valuable suggestions. > > > > > > Link: https://lore.kernel.org/lkml/20230907181459.18145-2-ankita@nvidia.com [1] > > > > That's a different series, no? It got merged at v9: > > I was confused by this too. v1 of that series included this patch, as > that series went along it became focused only on enabling WC > (Normal-NC) in a VM for device MMIO and this patch for device cachable > memory was dropped off. > > There are two related things: > 1) Device MMIO memory should be able to be Normal-NC in a VM. Already > merged > 2) Device Cachable memory (ie CXL and pre-CXL coherently attached > memory) should be Normal Cachable in a VM, even if it doesn't have > struct page/etc. (this patch) > > IIRC this part was dropped off because of the MTE complexity that > Catalin raised. Indeed, we only merged the Normal NC part at the time. I asked Ankit to drop the cacheable attributes and only focus on getting the other part merged. -- Catalin