Messages in this thread | | | Subject | Re: [PATCH v4 1/8] iommu: Add APIs for multiple domains per device | From | Lu Baolu <> | Date | Mon, 26 Nov 2018 10:04:30 +0800 |
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Hi Eric,
On 11/23/18 6:50 PM, Auger Eric wrote: > Hi Lu, > > On 11/5/18 8:34 AM, Lu Baolu wrote: >> Sharing a physical PCI device in a finer-granularity way >> is becoming a consensus in the industry. IOMMU vendors >> are also engaging efforts to support such sharing as well >> as possible. Among the efforts, the capability of support >> finer-granularity DMA isolation is a common requirement >> due to the security consideration. With finer-granularity >> DMA isolation, all DMA requests out of or to a subset of >> a physical PCI device can be protected by the IOMMU. As a >> result, there is a request in software to attach multiple >> domains to a physical PCI device. One example of such use >> model is the Intel Scalable IOV [1] [2]. The Intel vt-d >> 3.0 spec [3] introduces the scalable mode which enables >> PASID granularity DMA isolation. >> >> This adds the APIs to support multiple domains per device. >> In order to ease the discussions, we call it 'a domain in >> auxiliary mode' or simply 'auxiliary domain' when multiple >> domains are attached to a physical device. >> >> The APIs includes: >> >> * iommu_get_dev_attr(dev, IOMMU_DEV_ATTR_AUXD_CAPABILITY) >> - Represents the ability of supporting multiple domains >> per device. >> >> * iommu_get_dev_attr(dev, IOMMU_DEV_ATTR_AUXD_ENABLED) >> - Checks whether the device identified by @dev is working >> in auxiliary mode. >> >> * iommu_set_dev_attr(dev, IOMMU_DEV_ATTR_AUXD_ENABLE) >> - Enables the multiple domains capability for the device >> referenced by @dev. >> >> * iommu_set_dev_attr(dev, IOMMU_DEV_ATTR_AUXD_DISABLE) >> - Disables the multiple domains capability for the device >> referenced by @dev. >> >> * iommu_attach_device_aux(domain, dev) >> - Attaches @domain to @dev in the auxiliary mode. Multiple >> domains could be attached to a single device in the >> auxiliary mode with each domain representing an isolated >> address space for an assignable subset of the device. >> >> * iommu_detach_device_aux(domain, dev) >> - Detach @domain which has been attached to @dev in the >> auxiliary mode. >> >> * iommu_domain_get_attr(domain, DOMAIN_ATTR_AUXD_ID) >> - Return ID used for finer-granularity DMA translation. >> For the Intel Scalable IOV usage model, this will be >> a PASID. The device which supports Scalalbe IOV needs > s/Scalalbe/Scalable >> to writes this ID to the device register so that DMA > s/writes/write
Yes and thanks.
>> requests could be tagged with a right PASID prefix. > This is not crystal clear to me as the intel implementation returns the > default PASID and not the PASID of the aux domain.
The PASID of the aux domain is called default PASID.
>> >> Many people involved in discussions of this design. >> >> Kevin Tian <kevin.tian@intel.com> >> Liu Yi L <yi.l.liu@intel.com> >> Ashok Raj <ashok.raj@intel.com> >> Sanjay Kumar <sanjay.k.kumar@intel.com> >> Jacob Pan <jacob.jun.pan@linux.intel.com> >> Alex Williamson <alex.williamson@redhat.com> >> Jean-Philippe Brucker <jean-philippe.brucker@arm.com> >> >> and some discussions can be found here [4]. >> >> [1] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification >> [2] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf >> [3] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification >> [4] https://lkml.org/lkml/2018/7/26/4 >> >> Cc: Ashok Raj <ashok.raj@intel.com> >> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> >> Cc: Kevin Tian <kevin.tian@intel.com> >> Cc: Liu Yi L <yi.l.liu@intel.com> >> Suggested-by: Kevin Tian <kevin.tian@intel.com> >> Suggested-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- >> drivers/iommu/iommu.c | 52 +++++++++++++++++++++++++++++++++++++++++++ >> include/linux/iommu.h | 52 +++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 104 insertions(+) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index edbdf5d6962c..0b7c96d1425e 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -2030,3 +2030,55 @@ int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids) >> return 0; >> } >> EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); >> + >> +/* >> + * Generic interfaces to get or set per device IOMMU attributions. >> + */ >> +int iommu_get_dev_attr(struct device *dev, enum iommu_dev_attr attr, void *data) >> +{ >> + const struct iommu_ops *ops = dev->bus->iommu_ops; >> + >> + if (ops && ops->get_dev_attr) >> + return ops->get_dev_attr(dev, attr, data); >> + >> + return -EINVAL; >> +} >> +EXPORT_SYMBOL_GPL(iommu_get_dev_attr); >> + >> +int iommu_set_dev_attr(struct device *dev, enum iommu_dev_attr attr, void *data) >> +{ >> + const struct iommu_ops *ops = dev->bus->iommu_ops; >> + >> + if (ops && ops->set_dev_attr) >> + return ops->set_dev_attr(dev, attr, data); >> + >> + return -EINVAL; >> +} >> +EXPORT_SYMBOL_GPL(iommu_set_dev_attr); >> + >> +/* >> + * APIs to attach/detach a domain to/from a device in the >> + * auxiliary mode. >> + */ >> +int iommu_attach_device_aux(struct iommu_domain *domain, struct device *dev) >> +{ >> + int ret = -ENODEV; >> + >> + if (domain->ops->attach_dev_aux) >> + ret = domain->ops->attach_dev_aux(domain, dev); >> + >> + if (!ret) >> + trace_attach_device_to_domain(dev); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(iommu_attach_device_aux); >> + >> +void iommu_detach_device_aux(struct iommu_domain *domain, struct device *dev) >> +{ >> + if (domain->ops->detach_dev_aux) { >> + domain->ops->detach_dev_aux(domain, dev); >> + trace_detach_device_from_domain(dev); >> + } >> +} >> +EXPORT_SYMBOL_GPL(iommu_detach_device_aux); >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index a1d28f42cb77..9bf1b3f2457a 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -126,6 +126,7 @@ enum iommu_attr { >> DOMAIN_ATTR_NESTING, /* two stages of translation */ >> DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, >> DOMAIN_ATTR_MAX, >> + DOMAIN_ATTR_AUXD_ID, >> }; >> >> /* These are the possible reserved region types */ >> @@ -156,6 +157,14 @@ struct iommu_resv_region { >> enum iommu_resv_type type; >> }; >> >> +/* Per device IOMMU attributions */ >> +enum iommu_dev_attr { >> + IOMMU_DEV_ATTR_AUXD_CAPABILITY, >> + IOMMU_DEV_ATTR_AUXD_ENABLED, >> + IOMMU_DEV_ATTR_AUXD_ENABLE, >> + IOMMU_DEV_ATTR_AUXD_DISABLE, >> +}; >> + >> #ifdef CONFIG_IOMMU_API >> >> /** >> @@ -183,6 +192,8 @@ struct iommu_resv_region { >> * @domain_window_enable: Configure and enable a particular window for a domain >> * @domain_window_disable: Disable a particular window for a domain >> * @of_xlate: add OF master IDs to iommu grouping >> + * @get_dev_attr: get per device IOMMU attributions > s/attributions/attributes here and other locations?
Yes. It should be "attributes". Thanks.
>> + * @set_dev_attr: set per device IOMMU attributions >> * @pgsize_bitmap: bitmap of all possible supported page sizes >> */ >> struct iommu_ops { >> @@ -226,6 +237,15 @@ struct iommu_ops { >> int (*of_xlate)(struct device *dev, struct of_phandle_args *args); >> bool (*is_attach_deferred)(struct iommu_domain *domain, struct device *dev); >> >> + /* Get/set per device IOMMU attributions */ >> + int (*get_dev_attr)(struct device *dev, >> + enum iommu_dev_attr attr, void *data); >> + int (*set_dev_attr)(struct device *dev, >> + enum iommu_dev_attr attr, void *data); >> + /* Attach/detach aux domain */ >> + int (*attach_dev_aux)(struct iommu_domain *domain, struct device *dev); >> + void (*detach_dev_aux)(struct iommu_domain *domain, struct device *dev); >> + >> unsigned long pgsize_bitmap; >> }; >> >> @@ -398,6 +418,16 @@ void iommu_fwspec_free(struct device *dev); >> int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids); >> const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode); >> >> +int iommu_get_dev_attr(struct device *dev, >> + enum iommu_dev_attr attr, void *data); >> +int iommu_set_dev_attr(struct device *dev, >> + enum iommu_dev_attr attr, void *data); >> + >> +extern int iommu_attach_device_aux(struct iommu_domain *domain, >> + struct device *dev); >> +extern void iommu_detach_device_aux(struct iommu_domain *domain, >> + struct device *dev); >> + >> #else /* CONFIG_IOMMU_API */ >> >> struct iommu_ops {}; >> @@ -682,6 +712,28 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) >> return NULL; >> } >> >> +static inline int >> +iommu_get_dev_attr(struct device *dev, enum iommu_dev_attr attr, void *data) >> +{ >> + return -EINVAL; >> +} >> + >> +static inline int >> +iommu_set_dev_attr(struct device *dev, enum iommu_dev_attr attr, void *data) >> +{ >> + return -EINVAL; >> +} >> + >> +static inline int >> +iommu_attach_device_aux(struct iommu_domain *domain, struct device *dev) >> +{ >> + return -ENODEV; >> +} >> + >> +static inline void >> +iommu_detach_device_aux(struct iommu_domain *domain, struct device *dev) >> +{ >> +} >> #endif /* CONFIG_IOMMU_API */ >> >> #ifdef CONFIG_IOMMU_DEBUGFS >> > > Thanks > > Eric >
Best regards, Lu Baolu
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