From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Philippe Brucker Subject: Re: [virtio-dev] [RFC PATCH v2 4/5] ACPI/IORT: Support paravirtualized IOMMU Date: Wed, 29 Nov 2017 15:17:55 +0000 Message-ID: References: <20171117185211.32593-1-jean-philippe.brucker@arm.com> <20171117185211.32593-5-jean-philippe.brucker@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:40082 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754997AbdK2POs (ORCPT ); Wed, 29 Nov 2017 10:14:48 -0500 In-Reply-To: <20171117185211.32593-5-jean-philippe.brucker@arm.com> Content-Language: en-US Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "iommu@lists.linux-foundation.org" , "devel@acpica.org" , "linux-acpi@vger.kernel.org" , "kvm@vger.kernel.org" , "kvmarm@lists.cs.columbia.edu" , "virtualization@lists.linux-foundation.org" , "virtio-dev@lists.oasis-open.org" Cc: "jasowang@redhat.com" , "mst@redhat.com" , "lv.zheng@intel.com" , "robert.moore@intel.com" , "joro@8bytes.org" , "alex.williamson@redhat.com" , Sudeep Holla , "hanjun.guo@linaro.org" , Lorenzo Pieralisi , "lenb@kernel.org" , "rjw@rjwysocki.net" , Marc Zyngier , Robin Murphy , Will Deacon , "eric.auger@redhat.com" , "bharat.bhushan@nxp.com" , "Jayachandran.Nair@cavium.com" , ashok. On 17/11/17 18:52, Jean-Philippe Brucker wrote: > To describe the virtual topology in relation to a virtio-iommu device, > ACPI-based systems use a "paravirtualized IOMMU" IORT node. Add support > for it. > > This is a RFC because the IORT specification doesn't describe the > paravirtualized node at the moment, it is only provided as an example in > the virtio-iommu spec. What we need to do first is confirm that x86 > kernels are able to use the IORT driver with the virtio-iommu. There isn't > anything specific to arm64 in the driver but there might be other blockers > we're not aware of (I know for example that x86 also requires custom DMA > ops rather than iommu-dma ones, but it's unrelated) so this needs to be > tested on the x86 prototype. I tested IORT with an x86 guest, putting a virtio-iommu on the PCI bus and it worked fine :) x86 still requires additional code [1] for using the IOMMU DMA ops, and I'm not comfortable enough with x86 to write the patch, but for instantiating virtio-iommus and for enumerating endpoints/buses connected to them, IORT should suffice. Thanks, Jean [1] http://www.linux-arm.org/git?p=linux-jpb.git;a=patch;h=e910e224b58712151dda06df595a53ff07edef63;hp=e7f9475480c24c5f973711984b30cf6746ff3ec8 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-2727-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id C5B51581912F for ; Wed, 29 Nov 2017 07:14:48 -0800 (PST) From: Jean-Philippe Brucker References: <20171117185211.32593-1-jean-philippe.brucker@arm.com> <20171117185211.32593-5-jean-philippe.brucker@arm.com> Message-ID: Date: Wed, 29 Nov 2017 15:17:55 +0000 MIME-Version: 1.0 In-Reply-To: <20171117185211.32593-5-jean-philippe.brucker@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [virtio-dev] [RFC PATCH v2 4/5] ACPI/IORT: Support paravirtualized IOMMU To: "iommu@lists.linux-foundation.org" , "devel@acpica.org" , "linux-acpi@vger.kernel.org" , "kvm@vger.kernel.org" , "kvmarm@lists.cs.columbia.edu" , "virtualization@lists.linux-foundation.org" , "virtio-dev@lists.oasis-open.org" Cc: "jasowang@redhat.com" , "mst@redhat.com" , "lv.zheng@intel.com" , "robert.moore@intel.com" , "joro@8bytes.org" , "alex.williamson@redhat.com" , Sudeep Holla , "hanjun.guo@linaro.org" , Lorenzo Pieralisi , "lenb@kernel.org" , "rjw@rjwysocki.net" , Marc Zyngier , Robin Murphy , Will Deacon , "eric.auger@redhat.com" , "bharat.bhushan@nxp.com" , "Jayachandran.Nair@cavium.com" , "ashok.raj@intel.com" , "peterx@redhat.com" List-ID: On 17/11/17 18:52, Jean-Philippe Brucker wrote: > To describe the virtual topology in relation to a virtio-iommu device, > ACPI-based systems use a "paravirtualized IOMMU" IORT node. Add support > for it. > > This is a RFC because the IORT specification doesn't describe the > paravirtualized node at the moment, it is only provided as an example in > the virtio-iommu spec. What we need to do first is confirm that x86 > kernels are able to use the IORT driver with the virtio-iommu. There isn't > anything specific to arm64 in the driver but there might be other blockers > we're not aware of (I know for example that x86 also requires custom DMA > ops rather than iommu-dma ones, but it's unrelated) so this needs to be > tested on the x86 prototype. I tested IORT with an x86 guest, putting a virtio-iommu on the PCI bus and it worked fine :) x86 still requires additional code [1] for using the IOMMU DMA ops, and I'm not comfortable enough with x86 to write the patch, but for instantiating virtio-iommus and for enumerating endpoints/buses connected to them, IORT should suffice. Thanks, Jean [1] http://www.linux-arm.org/git?p=linux-jpb.git;a=patch;h=e910e224b58712151dda06df595a53ff07edef63;hp=e7f9475480c24c5f973711984b30cf6746ff3ec8 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org