> From: Jean-Philippe Brucker [mailto:jean-philippe.brucker@xxxxxxx] > Sent: Wednesday, February 14, 2018 10:54 PM > > The virtio IOMMU is a para-virtualized device, allowing to send IOMMU > requests such as map/unmap over virtio-mmio transport without > emulating > page tables. This implementation handles ATTACH, DETACH, MAP and > UNMAP > requests. > > The bulk of the code transforms calls coming from the IOMMU API into > corresponding virtio requests. Mappings are kept in an interval tree > instead of page tables. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> [...] > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > new file mode 100644 > index 000000000000..a9c9245e8ba2 > --- /dev/null > +++ b/drivers/iommu/virtio-iommu.c > @@ -0,0 +1,960 @@ > +/* > + * Virtio driver for the paravirtualized IOMMU > + * > + * Copyright (C) 2018 ARM Limited > + * Author: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> > + * > + * SPDX-License-Identifier: GPL-2.0 > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/amba/bus.h> > +#include <linux/delay.h> > +#include <linux/dma-iommu.h> > +#include <linux/freezer.h> > +#include <linux/interval_tree.h> > +#include <linux/iommu.h> > +#include <linux/module.h> > +#include <linux/of_iommu.h> > +#include <linux/of_platform.h> > +#include <linux/pci.h> > +#include <linux/platform_device.h> > +#include <linux/virtio.h> > +#include <linux/virtio_config.h> > +#include <linux/virtio_ids.h> > +#include <linux/wait.h> > + > +#include <uapi/linux/virtio_iommu.h> > + > +#define MSI_IOVA_BASE 0x8000000 > +#define MSI_IOVA_LENGTH 0x100000 this is ARM specific, and according to virtio-iommu spec isn't it better probed on the endpoint instead of hard-coding here? Thanks Kevin
