Hi, Based on Joao's suggestion, the iommufd nesting prerequisite series [1] is further splitted to host IOMMU device abstract part [2] and vIOMMU check/sync part. This series implements the 2nd part.
This enables vIOMMU to get host IOMMU cap/ecap information by implementing a new set/unset_iommu_device interface, then vIOMMU could check or sync with vIOMMU's own cap/ecap config. It works by having device side, i.e. VFIO, register either an IOMMULegacyDevice or IOMMUFDDevice to vIOMMU, which includes necessary data to archive that. Currently only VFIO device is supported, but it could also be used for other devices, i.e., VDPA. For coldplugged device, we can get its host IOMMU cap/ecap during qemu init, then check and sync into vIOMMU cap/ecap. For hotplugged device, vIOMMU cap/ecap is frozen, we could only check with vIOMMU cap/ecap, not allowed to update. If check fails, hotplugged will fail. This is also a prerequisite for incoming iommufd nesting series: 'intel_iommu: Enable stage-1 translation'. I didn't implement cap/ecap sync for legacy VFIO backend, would like to see what Eric want to put in IOMMULegacyDevice for virtio-iommu and if I can utilize some of them. Because it's becoming clear on community's suggestion, I'd like to remove rfc tag from this version. Qemu code can be found at: https://github.com/yiliu1765/qemu/tree/zhenzhong/iommufd_nesting_preq_part2_v1 [1] https://lore.kernel.org/qemu-devel/20240201072818.327930-1-zhenzhong.d...@intel.com [2] https://lists.gnu.org/archive/html/qemu-devel/2024-02/msg06314.html Thanks Zhenzhong Changelog: v1: - convert HostIOMMUDevice to sub object pointer in vtd_check_hdev rfcv2: - introduce common abstract HostIOMMUDevice and sub struct for different BEs (Eric, Cédric) - remove iommufd_device.[ch] (Cédric) - remove duplicate iommufd/devid define from VFIODevice (Eric) - drop the p in aliased_pbus and aliased_pdevfn (Eric) - assert devfn and iommu_bus in pci_device_get_iommu_bus_devfn (Cédric, Eric) - use errp in iommufd_device_get_info (Eric) - split and simplify cap/ecap check/sync code in intel_iommu.c (Cédric) - move VTDHostIOMMUDevice declaration to intel_iommu_internal.h (Cédric) - make '(vtd->cap_reg >> 16) & 0x3fULL' a MACRO and add missed '+1' (Cédric) - block migration if vIOMMU cap/ecap updated based on host IOMMU cap/ecap - add R-B Yi Liu (2): intel_iommu: Add set/unset_iommu_device callback intel_iommu: Add a framework to check and sync host IOMMU cap/ecap Zhenzhong Duan (4): intel_iommu: Extract out vtd_cap_init to initialize cap/ecap intel_iommu: Implement check and sync mechanism in iommufd mode intel_iommu: Use mgaw instead of s->aw_bits intel_iommu: Block migration if cap is updated hw/i386/intel_iommu_internal.h | 9 ++ include/hw/i386/intel_iommu.h | 4 + hw/i386/acpi-build.c | 3 +- hw/i386/intel_iommu.c | 287 ++++++++++++++++++++++++++------- 4 files changed, 245 insertions(+), 58 deletions(-) -- 2.34.1
