On Sun, Nov 12, 2023 at 09:44:18AM -0800, Moritz Fischer wrote:
> On Fri, Nov 03, 2023 at 01:44:55PM -0300, Jason Gunthorpe wrote:
> > This call chain is using dev->iommu->fwspec to pass around the fwspec
> > between the three parts (acpi_iommu_configure(), acpi_iommu_fwspec_init(),
> > iommu_probe_device()).
> >
> > However there is no locking around the accesses to dev->iommu, so this is
> > all racy.
> >
> > Allocate a clean, local, fwspec at the start of acpu_iommu_configure(),
> Nit: s/acpu_iommu_configure/acpi_iommu_configure_id() ?
Yep
Thanks
Jason
> > pass it through all functions on the stack to fill it with data, and
> > finally pass it into iommu_probe_device_fwspec() which will load it into
> > dev->iommu under a lock.
> >
> > Signed-off-by: Jason Gunthorpe <j...@nvidia.com>
>
> Reviewed-by: Moritz Fischer <m...@kernel.org>
> > ---
> > drivers/acpi/arm64/iort.c | 39 ++++++++---------
> > drivers/acpi/scan.c | 89 ++++++++++++++++++---------------------
> > drivers/acpi/viot.c | 44 ++++++++++---------
> > drivers/iommu/iommu.c | 5 +--
> > include/acpi/acpi_bus.h | 8 ++--
> > include/linux/acpi_iort.h | 3 +-
> > include/linux/acpi_viot.h | 5 ++-
> > include/linux/iommu.h | 2 +
> > 8 files changed, 97 insertions(+), 98 deletions(-)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 6496ff5a6ba20d..accd01dcfe93f5 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -1218,10 +1218,9 @@ static bool iort_pci_rc_supports_ats(struct
> > acpi_iort_node *node)
> > return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
> > }
> >
> > -static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node
> > *node,
> > - u32 streamid)
> > +static int iort_iommu_xlate(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct acpi_iort_node *node, u32 streamid)
> > {
> > - const struct iommu_ops *ops;
> > struct fwnode_handle *iort_fwnode;
> >
> > if (!node)
> > @@ -1239,17 +1238,14 @@ static int iort_iommu_xlate(struct device *dev,
> > struct acpi_iort_node *node,
> > * in the kernel or not, defer the IOMMU configuration
> > * or just abort it.
> > */
> > - ops = iommu_ops_from_fwnode(iort_fwnode);
> > - if (!ops)
> > - return iort_iommu_driver_enabled(node->type) ?
> > - -EPROBE_DEFER : -ENODEV;
> > -
> > - return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
> > + return acpi_iommu_fwspec_init(fwspec, dev, streamid, iort_fwnode,
> > + iort_iommu_driver_enabled(node->type));
> > }
> >
> > struct iort_pci_alias_info {
> > struct device *dev;
> > struct acpi_iort_node *node;
> > + struct iommu_fwspec *fwspec;
> > };
> >
> > static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
> > @@ -1260,7 +1256,7 @@ static int iort_pci_iommu_init(struct pci_dev *pdev,
> > u16 alias, void *data)
> >
> > parent = iort_node_map_id(info->node, alias, &streamid,
> > IORT_IOMMU_TYPE);
> > - return iort_iommu_xlate(info->dev, parent, streamid);
> > + return iort_iommu_xlate(info->fwspec, info->dev, parent, streamid);
> > }
> >
> > static void iort_named_component_init(struct device *dev,
> > @@ -1280,7 +1276,8 @@ static void iort_named_component_init(struct device
> > *dev,
> > dev_warn(dev, "Could not add device properties\n");
> > }
> >
> > -static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node
> > *node)
> > +static int iort_nc_iommu_map(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct acpi_iort_node *node)
> > {
> > struct acpi_iort_node *parent;
> > int err = -ENODEV, i = 0;
> > @@ -1293,13 +1290,13 @@ static int iort_nc_iommu_map(struct device *dev,
> > struct acpi_iort_node *node)
> > i++);
> >
> > if (parent)
> > - err = iort_iommu_xlate(dev, parent, streamid);
> > + err = iort_iommu_xlate(fwspec, dev, parent, streamid);
> > } while (parent && !err);
> >
> > return err;
> > }
> >
> > -static int iort_nc_iommu_map_id(struct device *dev,
> > +static int iort_nc_iommu_map_id(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > struct acpi_iort_node *node,
> > const u32 *in_id)
> > {
> > @@ -1308,7 +1305,7 @@ static int iort_nc_iommu_map_id(struct device *dev,
> >
> > parent = iort_node_map_id(node, *in_id, &streamid, IORT_IOMMU_TYPE);
> > if (parent)
> > - return iort_iommu_xlate(dev, parent, streamid);
> > + return iort_iommu_xlate(fwspec, dev, parent, streamid);
> >
> > return -ENODEV;
> > }
> > @@ -1322,15 +1319,16 @@ static int iort_nc_iommu_map_id(struct device *dev,
> > *
> > * Returns: 0 on success, <0 on failure
> > */
> > -int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
> > +int iort_iommu_configure_id(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + const u32 *id_in)
> > {
> > struct acpi_iort_node *node;
> > int err = -ENODEV;
> >
> > if (dev_is_pci(dev)) {
> > - struct iommu_fwspec *fwspec;
> > struct pci_bus *bus = to_pci_dev(dev)->bus;
> > - struct iort_pci_alias_info info = { .dev = dev };
> > + struct iort_pci_alias_info info = { .dev = dev,
> > + .fwspec = fwspec };
> >
> > node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> > iort_match_node_callback, &bus->dev);
> > @@ -1341,8 +1339,7 @@ int iort_iommu_configure_id(struct device *dev, const
> > u32 *id_in)
> > err = pci_for_each_dma_alias(to_pci_dev(dev),
> > iort_pci_iommu_init, &info);
> >
> > - fwspec = dev_iommu_fwspec_get(dev);
> > - if (fwspec && iort_pci_rc_supports_ats(node))
> > + if (iort_pci_rc_supports_ats(node))
> > fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
> > } else {
> > node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> > @@ -1350,8 +1347,8 @@ int iort_iommu_configure_id(struct device *dev, const
> > u32 *id_in)
> > if (!node)
> > return -ENODEV;
> >
> > - err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :
> > - iort_nc_iommu_map(dev, node);
> > + err = id_in ? iort_nc_iommu_map_id(fwspec, dev, node, id_in) :
> > + iort_nc_iommu_map(fwspec, dev, node);
> >
> > if (!err)
> > iort_named_component_init(dev, node);
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index fbabde001a23a2..1e01a8e0316867 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -1543,74 +1543,67 @@ int acpi_dma_get_range(struct device *dev, const
> > struct bus_dma_region **map)
> > }
> >
> > #ifdef CONFIG_IOMMU_API
> > -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> > - struct fwnode_handle *fwnode,
> > - const struct iommu_ops *ops)
> > +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> > + u32 id, struct fwnode_handle *fwnode,
> > + bool iommu_driver_available)
> > {
> > - int ret = iommu_fwspec_init(dev, fwnode, ops);
> > + int ret;
> >
> > - if (!ret)
> > - ret = iommu_fwspec_add_ids(dev, &id, 1);
> > -
> > - return ret;
> > -}
> > -
> > -static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device
> > *dev)
> > -{
> > - struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> > -
> > - return fwspec ? fwspec->ops : NULL;
> > + ret = iommu_fwspec_assign_iommu(fwspec, dev, fwnode);
> > + if (ret) {
> > + if (ret == -EPROBE_DEFER && !iommu_driver_available)
> > + return -ENODEV;
> > + return ret;
> > + }
> > + return iommu_fwspec_append_ids(fwspec, &id, 1);
> > }
> >
> > static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
> > {
> > int err;
> > - const struct iommu_ops *ops;
> > + struct iommu_fwspec *fwspec;
> >
> > - /*
> > - * If we already translated the fwspec there is nothing left to do,
> > - * return the iommu_ops.
> > - */
> > - ops = acpi_iommu_fwspec_ops(dev);
> > - if (ops)
> > - return 0;
> > + fwspec = iommu_fwspec_alloc();
> > + if (IS_ERR(fwspec))
> > + return PTR_ERR(fwspec);
> >
> > - err = iort_iommu_configure_id(dev, id_in);
> > - if (err && err != -EPROBE_DEFER)
> > - err = viot_iommu_configure(dev);
> > + err = iort_iommu_configure_id(fwspec, dev, id_in);
> > + if (err == -ENODEV)
> > + err = viot_iommu_configure(fwspec, dev);
> > + if (err == -ENODEV || err == -EPROBE_DEFER)
> > + goto err_free;
> > + if (err)
> > + goto err_log;
> >
> > - /*
> > - * If we have reason to believe the IOMMU driver missed the initial
> > - * iommu_probe_device() call for dev, replay it to get things in order.
> > - */
> > - if (!err && dev->bus)
> > - err = iommu_probe_device(dev);
> > -
> > - /* Ignore all other errors apart from EPROBE_DEFER */
> > - if (err == -EPROBE_DEFER) {
> > - return err;
> > - } else if (err) {
> > - dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
> > - return -ENODEV;
> > + err = iommu_probe_device_fwspec(dev, fwspec);
> > + if (err) {
> > + /*
> > + * Ownership for fwspec always passes into
> > + * iommu_probe_device_fwspec()
> > + */
> > + fwspec = NULL;
> > + goto err_log;
> > }
> > - if (!acpi_iommu_fwspec_ops(dev))
> > - return -ENODEV;
> > - return 0;
> > +
> > +err_log:
> > + dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
> > +err_free:
> > + iommu_fwspec_dealloc(fwspec);
> > + return err;
> > }
> >
> > #else /* !CONFIG_IOMMU_API */
> >
> > -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> > - struct fwnode_handle *fwnode,
> > - const struct iommu_ops *ops)
> > +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> > + u32 id, struct fwnode_handle *fwnode,
> > + bool iommu_driver_available)
> > {
> > return -ENODEV;
> > }
> >
> > -static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
> > - const u32 *id_in)
> > +static const int acpi_iommu_configure_id(struct device *dev, const u32
> > *id_in)
> > {
> > - return NULL;
> > + return -ENODEV;
> > }
> >
> > #endif /* !CONFIG_IOMMU_API */
> > diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
> > index c8025921c129b2..33b511dd202d15 100644
> > --- a/drivers/acpi/viot.c
> > +++ b/drivers/acpi/viot.c
> > @@ -304,11 +304,9 @@ void __init acpi_viot_init(void)
> > acpi_put_table(hdr);
> > }
> >
> > -static int viot_dev_iommu_init(struct device *dev, struct viot_iommu
> > *viommu,
> > - u32 epid)
> > +static int viot_dev_iommu_init(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct viot_iommu *viommu, u32 epid)
> > {
> > - const struct iommu_ops *ops;
> > -
> > if (!viommu)
> > return -ENODEV;
> >
> > @@ -316,19 +314,20 @@ static int viot_dev_iommu_init(struct device *dev,
> > struct viot_iommu *viommu,
> > if (device_match_fwnode(dev, viommu->fwnode))
> > return -EINVAL;
> >
> > - ops = iommu_ops_from_fwnode(viommu->fwnode);
> > - if (!ops)
> > - return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ?
> > - -EPROBE_DEFER : -ENODEV;
> > -
> > - return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops);
> > + return acpi_iommu_fwspec_init(fwspec, dev, epid, viommu->fwnode,
> > + IS_ENABLED(CONFIG_VIRTIO_IOMMU));
> > }
> >
> > +struct viot_pci_alias_info {
> > + struct device *dev;
> > + struct iommu_fwspec *fwspec;
> > +};
> > +
> > static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void
> > *data)
> > {
> > u32 epid;
> > struct viot_endpoint *ep;
> > - struct device *aliased_dev = data;
> > + struct viot_pci_alias_info *info = data;
> > u32 domain_nr = pci_domain_nr(pdev->bus);
> >
> > list_for_each_entry(ep, &viot_pci_ranges, list) {
> > @@ -339,14 +338,15 @@ static int viot_pci_dev_iommu_init(struct pci_dev
> > *pdev, u16 dev_id, void *data)
> > epid = ((domain_nr - ep->segment_start) << 16) +
> > dev_id - ep->bdf_start + ep->endpoint_id;
> >
> > - return viot_dev_iommu_init(aliased_dev, ep->viommu,
> > - epid);
> > + return viot_dev_iommu_init(info->fwspec, info->dev,
> > + ep->viommu, epid);
> > }
> > }
> > return -ENODEV;
> > }
> >
> > -static int viot_mmio_dev_iommu_init(struct platform_device *pdev)
> > +static int viot_mmio_dev_iommu_init(struct iommu_fwspec *fwspec,
> > + struct platform_device *pdev)
> > {
> > struct resource *mem;
> > struct viot_endpoint *ep;
> > @@ -357,8 +357,8 @@ static int viot_mmio_dev_iommu_init(struct
> > platform_device *pdev)
> >
> > list_for_each_entry(ep, &viot_mmio_endpoints, list) {
> > if (ep->address == mem->start)
> > - return viot_dev_iommu_init(&pdev->dev, ep->viommu,
> > - ep->endpoint_id);
> > + return viot_dev_iommu_init(fwspec, &pdev->dev,
> > + ep->viommu, ep->endpoint_id);
> > }
> > return -ENODEV;
> > }
> > @@ -369,12 +369,16 @@ static int viot_mmio_dev_iommu_init(struct
> > platform_device *pdev)
> > *
> > * Return: 0 on success, <0 on failure
> > */
> > -int viot_iommu_configure(struct device *dev)
> > +int viot_iommu_configure(struct iommu_fwspec *fwspec, struct device *dev)
> > {
> > - if (dev_is_pci(dev))
> > + if (dev_is_pci(dev)) {
> > + struct viot_pci_alias_info info = { .dev = dev,
> > + .fwspec = fwspec };
> > return pci_for_each_dma_alias(to_pci_dev(dev),
> > - viot_pci_dev_iommu_init, dev);
> > + viot_pci_dev_iommu_init, &info);
> > + }
> > else if (dev_is_platform(dev))
> > - return viot_mmio_dev_iommu_init(to_platform_device(dev));
> > + return viot_mmio_dev_iommu_init(fwspec,
> > + to_platform_device(dev));
> > return -ENODEV;
> > }
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index 15dbe2d9eb24c2..9cfba9d12d1400 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -2960,9 +2960,8 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct
> > fwnode_handle *fwnode)
> > return ops;
> > }
> >
> > -static int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec,
> > - struct device *dev,
> > - struct fwnode_handle *iommu_fwnode)
> > +int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct fwnode_handle *iommu_fwnode)
> > {
> > const struct iommu_ops *ops;
> >
> > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> > index 254685085c825c..70f97096c776e4 100644
> > --- a/include/acpi/acpi_bus.h
> > +++ b/include/acpi/acpi_bus.h
> > @@ -12,6 +12,8 @@
> > #include <linux/device.h>
> > #include <linux/property.h>
> >
> > +struct iommu_fwspec;
> > +
> > /* TBD: Make dynamic */
> > #define ACPI_MAX_HANDLES 10
> > struct acpi_handle_list {
> > @@ -625,9 +627,9 @@ struct acpi_pci_root {
> >
> > bool acpi_dma_supported(const struct acpi_device *adev);
> > enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
> > -int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> > - struct fwnode_handle *fwnode,
> > - const struct iommu_ops *ops);
> > +int acpi_iommu_fwspec_init(struct iommu_fwspec *fwspec, struct device *dev,
> > + u32 id, struct fwnode_handle *fwnode,
> > + bool iommu_driver_available);
> > int acpi_dma_get_range(struct device *dev, const struct bus_dma_region
> > **map);
> > int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
> > const u32 *input_id);
> > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> > index 1cb65592c95dd3..80794ec45d1693 100644
> > --- a/include/linux/acpi_iort.h
> > +++ b/include/linux/acpi_iort.h
> > @@ -40,7 +40,8 @@ void iort_put_rmr_sids(struct fwnode_handle *iommu_fwnode,
> > struct list_head *head);
> > /* IOMMU interface */
> > int iort_dma_get_ranges(struct device *dev, u64 *size);
> > -int iort_iommu_configure_id(struct device *dev, const u32 *id_in);
> > +int iort_iommu_configure_id(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + const u32 *id_in);
> > void iort_iommu_get_resv_regions(struct device *dev, struct list_head
> > *head);
> > phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
> > #else
> > diff --git a/include/linux/acpi_viot.h b/include/linux/acpi_viot.h
> > index a5a12243156377..f1874cb6d43c09 100644
> > --- a/include/linux/acpi_viot.h
> > +++ b/include/linux/acpi_viot.h
> > @@ -8,11 +8,12 @@
> > #ifdef CONFIG_ACPI_VIOT
> > void __init acpi_viot_early_init(void);
> > void __init acpi_viot_init(void);
> > -int viot_iommu_configure(struct device *dev);
> > +int viot_iommu_configure(struct iommu_fwspec *fwspec, struct device *dev);
> > #else
> > static inline void acpi_viot_early_init(void) {}
> > static inline void acpi_viot_init(void) {}
> > -static inline int viot_iommu_configure(struct device *dev)
> > +static inline int viot_iommu_configure(struct iommu_fwspec *fwspec,
> > + struct device *dev)
> > {
> > return -ENODEV;
> > }
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index c5a5e2b5e2cc2a..27e4605d498850 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -688,6 +688,8 @@ void iommu_fwspec_dealloc(struct iommu_fwspec *fwspec);
> > int iommu_fwspec_of_xlate(struct iommu_fwspec *fwspec, struct device *dev,
> > struct fwnode_handle *iommu_fwnode,
> > struct of_phandle_args *iommu_spec);
> > +int iommu_fwspec_assign_iommu(struct iommu_fwspec *fwspec, struct device
> > *dev,
> > + struct fwnode_handle *iommu_fwnode);
> >
> > int iommu_fwspec_init(struct device *dev, struct fwnode_handle
> > *iommu_fwnode,
> > const struct iommu_ops *ops);
