Re: [PATCH v2 06/19] iommufd/viommu: Add IOMMU_VIOMMU_SET/UNSET_VDEV_ID ioctl

On Wed, Apr 30, 2025 at 12:58:47AM -0700, Nicolin Chen wrote:

quoted

... and I just hit a problem with it - this is basically guest BDFn
and it works as long as I'm hotplugging the TEE-IO VF into an SNP VM
but does not when I pass through via the QEMU cmdline - bus numbers
are not assigned yet. So I have to postpone the vdevice allocation
till run time, did I miss something here? Thanks,

I have a similar case with QEMU ARM64's VM: so vDEVICE on ARM is
allocated at runtime as well because the BDF number isn't ready
at the boot time.

Oh that's ugly then.. So you'll need to add some kind of 'modify
sid/bdf' operation I think.

The bus numbers can be reassigned at any time on the fly by the guest
by reprogramming the PCI hierarchy.

Jason