From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756054AbcJFUUL (ORCPT ); Thu, 6 Oct 2016 16:20:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37562 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754077AbcJFUTt (ORCPT ); Thu, 6 Oct 2016 16:19:49 -0400 Date: Thu, 6 Oct 2016 14:19:18 -0600 From: Alex Williamson To: Eric Auger Cc: eric.auger.pro@gmail.com, christoffer.dall@linaro.org, marc.zyngier@arm.com, robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, drjones@redhat.com, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, yehuday@marvell.com, Manish.Jaggi@caviumnetworks.com Subject: Re: [PATCH v13 11/15] vfio/type1: Handle unmap/unpin and replay for VFIO_IOVA_RESERVED slots Message-ID: <20161006141918.67928391@t450s.home> In-Reply-To: <1475743531-4780-12-git-send-email-eric.auger@redhat.com> References: <1475743531-4780-1-git-send-email-eric.auger@redhat.com> <1475743531-4780-12-git-send-email-eric.auger@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 06 Oct 2016 20:19:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 6 Oct 2016 08:45:27 +0000 Eric Auger wrote: > Before allowing the end-user to create VFIO_IOVA_RESERVED dma slots, > let's implement the expected behavior for removal and replay. > > As opposed to user dma slots, reserved IOVAs are not systematically bound > to PAs and PAs are not pinned. VFIO just initializes the IOVA "aperture". > IOVAs are allocated outside of the VFIO framework, by the MSI layer which > is responsible to free and unmap them. The MSI mapping resources are freeed nit, extra 'e', "freed" > by the IOMMU driver on domain destruction. > > On the creation of a new domain, the "replay" of a reserved slot simply > needs to set the MSI aperture on the new domain. > > Signed-off-by: Eric Auger > > --- > v12 -> v13: > - use dma-iommu iommu_get_dma_msi_region_cookie > > v9 -> v10: > - replay of a reserved slot sets the MSI aperture on the new domain > - use VFIO_IOVA_RESERVED_MSI enum value instead of VFIO_IOVA_RESERVED > > v7 -> v8: > - do no destroy anything anymore, just bypass unmap/unpin and iommu_map > on replay > --- > drivers/vfio/Kconfig | 1 + > drivers/vfio/vfio_iommu_type1.c | 10 +++++++++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig > index da6e2ce..673ec79 100644 > --- a/drivers/vfio/Kconfig > +++ b/drivers/vfio/Kconfig > @@ -1,6 +1,7 @@ > config VFIO_IOMMU_TYPE1 > tristate > depends on VFIO > + select IOMMU_DMA > default n > > config VFIO_IOMMU_SPAPR_TCE > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 65a4038..5bc5fc9 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -36,6 +36,7 @@ > #include > #include > #include > +#include > > #define DRIVER_VERSION "0.2" > #define DRIVER_AUTHOR "Alex Williamson " > @@ -387,7 +388,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma) > struct vfio_domain *domain, *d; > long unlocked = 0; > > - if (!dma->size) > + if (!dma->size || dma->type != VFIO_IOVA_USER) > return; > /* > * We use the IOMMU to track the physical addresses, otherwise we'd > @@ -724,6 +725,13 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu, > dma = rb_entry(n, struct vfio_dma, node); > iova = dma->iova; > > + if (dma->type == VFIO_IOVA_RESERVED_MSI) { > + ret = iommu_get_dma_msi_region_cookie(domain->domain, > + dma->iova, dma->size); > + WARN_ON(ret); > + continue; > + } Why is this a passable error? We consider an iommu_map() error on any entry a failure. > + > while (iova < dma->iova + dma->size) { > phys_addr_t phys = iommu_iova_to_phys(d->domain, iova); > size_t size;