Messages in this thread | | | Date | Thu, 5 May 2022 14:28:09 +0800 | Subject | Re: [PATCH v5 03/12] iommu: Add attach/detach_dev_pasid domain ops | From | Baolu Lu <> |
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On 2022/5/4 02:07, Jean-Philippe Brucker wrote: > On Mon, May 02, 2022 at 09:48:33AM +0800, Lu Baolu wrote: >> Attaching an IOMMU domain to a PASID of a device is a generic operation >> for modern IOMMU drivers which support PASID-granular DMA address >> translation. Currently visible usage scenarios include (but not limited): >> >> - SVA (Shared Virtual Address) >> - kernel DMA with PASID >> - hardware-assist mediated device >> >> This adds a pair of common domain ops for this purpose and adds helpers >> to attach/detach a domain to/from a {device, PASID}. Some buses, like >> PCI, route packets without considering the PASID value. Thus a DMA target >> address with PASID might be treated as P2P if the address falls into the >> MMIO BAR of other devices in the group. To make things simple, these >> interfaces only apply to devices belonging to the singleton groups, and >> the singleton is immutable in fabric i.e. not affected by hotplug. >> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > > Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org> > > just a nit below > >> --- >> include/linux/iommu.h | 21 ++++++++++++ >> drivers/iommu/iommu.c | 76 +++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 97 insertions(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index b8ffaf2cb1d0..ab36244d4e94 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -263,6 +263,8 @@ struct iommu_ops { >> * struct iommu_domain_ops - domain specific operations >> * @attach_dev: attach an iommu domain to a device >> * @detach_dev: detach an iommu domain from a device >> + * @attach_dev_pasid: attach an iommu domain to a pasid of device >> + * @detach_dev_pasid: detach an iommu domain from a pasid of device >> * @map: map a physically contiguous memory region to an iommu domain >> * @map_pages: map a physically contiguous set of pages of the same size to >> * an iommu domain. >> @@ -283,6 +285,10 @@ struct iommu_ops { >> struct iommu_domain_ops { >> int (*attach_dev)(struct iommu_domain *domain, struct device *dev); >> void (*detach_dev)(struct iommu_domain *domain, struct device *dev); >> + int (*attach_dev_pasid)(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> + void (*detach_dev_pasid)(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> >> int (*map)(struct iommu_domain *domain, unsigned long iova, >> phys_addr_t paddr, size_t size, int prot, gfp_t gfp); >> @@ -678,6 +684,10 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); >> void iommu_group_release_dma_owner(struct iommu_group *group); >> bool iommu_group_dma_owner_claimed(struct iommu_group *group); >> >> +int iommu_attach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> +void iommu_detach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid); >> #else /* CONFIG_IOMMU_API */ >> >> struct iommu_ops {}; >> @@ -1051,6 +1061,17 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) >> { >> return false; >> } >> + >> +static inline int iommu_attach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid) >> +{ >> + return -ENODEV; >> +} >> + >> +static inline void iommu_detach_device_pasid(struct iommu_domain *domain, >> + struct device *dev, ioasid_t pasid) >> +{ >> +} >> #endif /* CONFIG_IOMMU_API */ >> >> /** >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 29906bc16371..89c9d19ddb28 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -38,6 +38,7 @@ struct iommu_group { >> struct kobject kobj; >> struct kobject *devices_kobj; >> struct list_head devices; >> + struct xarray pasid_array; >> struct mutex mutex; >> void *iommu_data; >> void (*iommu_data_release)(void *iommu_data); >> @@ -630,6 +631,7 @@ struct iommu_group *iommu_group_alloc(void) >> mutex_init(&group->mutex); >> INIT_LIST_HEAD(&group->devices); >> INIT_LIST_HEAD(&group->entry); >> + xa_init(&group->pasid_array); >> >> ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); >> if (ret < 0) { >> @@ -3190,3 +3192,77 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group) >> return user; >> } >> EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); >> + >> +/* >> + * Use standard PCI bus topology and isolation features to check immutable >> + * singleton. Otherwise, assume the bus is static and then singleton can >> + * know from the device count in the group. >> + */ > > The comment doesn't really add anything that can't be directly understood > from the code.
Yes. It's fine to remove it.
Best regards, baolu
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