On 5/16/2025 3:19 AM, Shameerali Kolothum Thodi wrote:
Hi,
This is a follow up to the first RFC patchset [0] for supporting multiple vSMMU instances in a qemu VM. This patchset also introduces support for using iommufd to propagate DMA mappings to kernel for assigned devices.
This patchset implements support for specifying multiple <iommu> devices within the VM definition when smmuv3Dev IOMMU model is specified, and is tested with Shameer's latest qemu RFC for HW-accelerated vSMMU devices [1] Based on feedback released on the above RFC and the discussion here[1], there are certain changes to the name of the vSMMU device and the way we associate the PCIe bus.
Going forward it is more likely to be something like below,
-device arm-smmuv3,primary-bus=pcie.0,accel=on -device vfio-pci,host=xxx,,bus=pcie.0 -device pxb-pcie,id=pcie.1,bus_nr=2 -device arm-smmuv3,primary-bus=pcie.1,accel=on ...
Hopefully, this doesn't warrant any major changes to this libvirt series, but please do make a note of it.
Thanks, Shameer
Thanks Shameer, I will make a note of this for the next revision. Best, Nathan