On Thu, 13 Mar 2025 05:47:48 -0700 Yi Liu <yi.l.liu@xxxxxxxxx> wrote: > This series introduces the PASID attach/detach user APIs (uAPIs) that > allow userspace to attach or detach a device's PASID to or from a specified > IOAS/hwpt. Currently, only the vfio-pci driver is enabled in this series. > > Following this update, PASID-capable devices bound to vfio-pci can report > PASID capabilities to userspace and virtual machines (VMs), facilitating > PASID use cases such as Shared Virtual Addressing (SVA). In discussions > about reporting the virtual PASID (vPASID) to VMs [1], it was agreed that > the userspace virtual machine monitor (VMM) will synthesize the vPASID > capability. The VMM must identify a suitable location to insert the vPASID > capability, including handling hidden bits for certain devices. However, > this responsibility lies with userspace and is not the focus of this series. > > This series begins by adding helpers for PASID attachment in the vfio core, > then extends the device character device (cdev) attach/detach ioctls to > support PASID attach/detach operations. At the conclusion of this series, > the IOMMU_GET_HW_INFO ioctl is extended to report PCI PASID capabilities > to userspace. Userspace should verify this capability before utilizing any > PASID-related uAPIs provided by VFIO, as agreed in [2]. This series depends > on the iommufd PASID attach/detach series [3]. > > The complete code is available at [4] and has been tested with a modified > QEMU branch [5]. What's missing for this to go in and which tree will take it? At a glance it seems like 4/ needs a PCI sign-off and 5/ needs an IOMMUFD sign-off. Thanks, Alex
