On Tue, Jun 15, 2021 at 10:59:06PM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe <j...@nvidia.com> > > Sent: Tuesday, June 15, 2021 11:07 PM > > > > On Tue, Jun 15, 2021 at 08:59:25AM +0000, Tian, Kevin wrote: > > > Hi, Jason, > > > > > > > From: Jason Gunthorpe > > > > Sent: Thursday, June 3, 2021 9:05 PM > > > > > > > > On Thu, Jun 03, 2021 at 06:39:30AM +0000, Tian, Kevin wrote: > > > > > > > Two helper functions are provided to support VFIO_ATTACH_IOASID: > > > > > > > > > > > > > > struct attach_info { > > > > > > > u32 ioasid; > > > > > > > // If valid, the PASID to be used physically > > > > > > > u32 pasid; > > > > > > > }; > > > > > > > int ioasid_device_attach(struct ioasid_dev *dev, > > > > > > > struct attach_info info); > > > > > > > int ioasid_device_detach(struct ioasid_dev *dev, u32 ioasid); > > > > > > > > > > > > Honestly, I still prefer this to be highly explicit as this is where > > > > > > all device driver authors get invovled: > > > > > > > > > > > > ioasid_pci_device_attach(struct pci_device *pdev, struct ioasid_dev > > *dev, > > > > > > u32 ioasid); > > > > > > ioasid_pci_device_pasid_attach(struct pci_device *pdev, u32 > > > > *physical_pasid, > > > > > > struct ioasid_dev *dev, u32 ioasid); > > > > > > > > > > Then better naming it as pci_device_attach_ioasid since the 1st > > parameter > > > > > is struct pci_device? > > > > > > > > No, the leading tag indicates the API's primary subystem, in this case > > > > it is iommu (and if you prefer list the iommu related arguments first) > > > > > > > > > > I have a question on this suggestion when working on v2. > > > > > > Within IOMMU fd it uses only the generic struct device pointer, which > > > is already saved in struct ioasid_dev at device bind time: > > > > > > struct ioasid_dev *ioasid_register_device(struct ioasid_ctx *ctx, > > > struct device *device, u64 device_label); > > > > > > What does this additional struct pci_device bring when it's specified in > > > the attach call? If we save it in attach_data, at which point will it be > > > used or checked? > > > > The above was for attaching to an ioasid not the register path > > Yes, I know. and this is my question. When receiving a struct pci_device > at attach time, what should IOMMU fd do with it? Just verify whether > pci_device->device is same as ioasid_dev->device? if saving it to per-device > attach data under ioasid then when will it be further used? > > I feel once ioasid_dev is returned in the register path, following operations > (unregister, attach, detach) just uses ioasid_dev as the main object.
The point of having the pci_device specific API was to convey bus specific information during the attachment to the IOASID. The registration of the device to the iommu_fd doesn't need bus specific information, AFIAK? So just use a normal struct device pointer Jason _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu