> From: Nicolin Chen <nicolinc@xxxxxxxxxx> > Sent: Wednesday, March 15, 2023 5:03 PM > > Hi, > > On Wed, Mar 15, 2023 at 06:50:53AM +0000, Tian, Kevin wrote: > > > > So, this preparatory series will add a pair of simple attach() > > > and detach() APIs. Then the cdev series will add the locking > > > and the ioas_unpin stuff as a rework of the detach() API. > > > > I think they can be something mingled... the sample code that > > > I sent previously could take care of those conditions. But, I > > > am also thinking a bit that maybe attach() does not need the > > > locking? I can do a separate replace() function in this case. > > > > > > > w/o locking then you need smp_store_release() and its pair. > > > > anyway it's not in perf critical path. Keeping lock for attach > > is simpler and safe. > > OK. Basically I followed what Jason suggested by having three > APIs and combined Kevin's inputs about the difference between > the attach/replace(). I also updated the replace changes, and > rebased all nesting (infrastructure, VT-d and SMMU): > https://github.com/nicolinc/iommufd/commits/wip/iommufd_nesting-03142023 > > The major three changes for those APIs: > [1] This adds iommufd_access_attach() in this series: > "iommufd: Create access in vfio_iommufd_emulated_bind()" > > https://github.com/nicolinc/iommufd/commit/34fba7509429380f828fb23dc > ca5ceaeb40e22b5 > [2] This adds iommufd_access_detach() in the cdev series: > "iommufd/device: Add iommufd_access_detach() API" > > https://github.com/nicolinc/iommufd/commit/4110522146ca1fc0d5321c04a > 097e2c9d9e26af4 > [3] This adds iommufd_access_replace() in the replace series: > "iommufd: Add iommufd_access_replace() API" > > https://github.com/nicolinc/iommufd/commit/36507fa9f0f42cf1a5bebe7c9 > bc2bf319b7654a8 > > Please check if they look okay, so that Yi can integrate them > accordingly to the emulated/cdev series. Thanks. I'll start to integrate after ack from Kevin or Jason. btw. Below is my latest code (rebased on top of rc-2). 😊 https://github.com/yiliu1765/iommufd/tree/wip/vfio_device_cdev_v7_candidate > > [*] This is the patch that I posted in the other mail addressing > Kevin's comments on iommufd_ctx_get(): > "iommufd/device: Do iommufd_ctx_get() at the top of > iommufd_access_create()" > > https://github.com/nicolinc/iommufd/commit/077b09bb83329dc046753f4ef > 672f5bf6386755c > (I just saw Yi's reply concerning its necessity. Feel free > to drop in that case.) Yeah, let's see Kevin's feedback. > > Thanks > Nicolin > > P.S. Attaching the list of changes with their locations: > 3791dedf98e8 cover-letter: Add IO page table replacement support > c8ebf51c3c9b vfio: Support IO page table replacement > c5710f23e8f6 iommufd/selftest: Add > IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage > [3] 36507fa9f0f4 iommufd: Add iommufd_access_replace() API > 0263855d1e8b vfio: Do not allow !ops->dma_unmap in > vfio_pin/unpin_pages() > e39ed55e77a0 cover-letter: Add vfio_device cdev for iommufd support > 26fd7fccaef3 docs: vfio: Add vfio device cdev description > f10f3e3162bb vfio: Compile group optionally > 9588ae4c4049 vfio: Add VFIO_DEVICE_AT[DE]TACH_IOMMUFD_PT > 3e57108eac64 vfio: Add VFIO_DEVICE_BIND_IOMMUFD > b925716dd226 vfio: Add cdev for vfio_device > db309463ab92 vfio-iommufd: Add detach_ioas support for emulated VFIO > devices > [2] 4110522146ca iommufd/device: Add iommufd_access_detach() API > abca7e1e063a vfio-iommufd: Add detach_ioas support for physical VFIO > devices > 9d368f7247c7 vfio: Record devid in vfio_device_file > 683af0a471e1 vfio-iommufd: Split the compat_ioas attach out from > vfio_iommufd_bind() > 32a2e7de1d53 vfio-iommufd: Split the no-iommu support out from > vfio_iommufd_bind() > 8a1c042379f5 vfio: Make vfio_device_first_open() to accept NULL iommufd > for noiommu > fc6e0ed2aa44 vfio: Make vfio_device_open() single open for device cdev > path > 3f6821d507a4 vfio: Add cdev_device_open_cnt to vfio_group > 896cde40a016 vfio: Block device access via device fd until device is opened > f422c4216a19 vfio: Pass struct vfio_device_file * to vfio_device_open/close() > b187f9980fed kvm/vfio: Accept vfio device file from userspace > 721e2e60ff54 kvm/vfio: Rename kvm_vfio_group to prepare for accepting > vfio device fd > 8993c4c75c20 vfio: Accept vfio device file in the KVM facing kAPI > a92c45ae0ce6 vfio: Remove vfio_file_is_group() > fb586f783934 vfio: Refine vfio file kAPIs for KVM > 50694af6f3c0 vfio: Allocate per device file structure > df21c0737eef cover-letter: Make vfio-pci hot reset prepared for vfio device > cdev > 5c25c874d7e0 vfio/pci: Accept device fd in VFIO_DEVICE_PCI_HOT_RESET > ioctl > 7c30ce8b54db vfio: Accpet device file from vfio PCI hot reset path > e3209342db44 vfio: Refine vfio file kAPIs for vfio PCI hot reset > 8354fd79944e vfio/pci: Rename the helpers and data in hot reset path to > accept device fd > 54387efb858c vfio/pci: Allow passing zero-length fd array in > VFIO_DEVICE_PCI_HOT_RESET > cd93ffb62c51 vfio/pci: Only need to check opened devices in the dev_set > for hot reset > 2a6fd7231cbf vfio/pci: Update comment around group_fd get in > vfio_pci_ioctl_pci_hot_reset() > 480abea5961e cover-letter: vfio: Make emulated devices prepared for vfio > device cdev > 46b6d1ae1754 vfio: Check the presence for iommufd callbacks in > __vfio_register_dev() > 6064b9f81817 Samples/mdev: Uses the vfio emulated iommufd ops set in > the mdev sample drivers > c20852af7291 vfio-iommufd: Make vfio_iommufd_emulated_bind() return > iommufd_access ID > 3405865b0b3f vfio-iommufd: No need to record iommufd_ctx in vfio_device > [*] 077b09bb8332 iommufd/device: Do iommufd_ctx_get() at the top of > iommufd_access_create() > [1] 34fba7509429 iommufd: Create access in vfio_iommufd_emulated_bind() > a5d8ac47554f docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD > before VFIO_GROUP_GET_DEVICE_FD
