On 26/02/27 03:43PM, shivang upadhyay wrote: > > <...snip...> > > > > Q: can the generated DBT genuinely be different on a > > subsequent reset than it was when QEMU first starts? > > The comments in the pnv_reset() code seem to suggest it, > > but on the other hand the code as written will only > > call pnv_dt_create() and update machine->fdt once on first > > reset, not on later resets. So perhaps the comment is > > just confusingly worded ? > > Yes, I am not much familiar with the design here. But, as per > > my current understanding of this code, DTB content should not > > not be changed.
To add to this, yes, normally reset path doesn't change the device tree, since all reboots are the same as the first boot. As of upstream this is true, I don't see dtb changing between resets. One case where reset path does change the device tree compared to pnv_init part is Memory-Preserving IPL (MPIPL), which is a dump-collection feature in powernv for collecting dumps after kernel crashes. This is not merged yet in upstream, and is currently in discussion [1]. I am okay with the dead if condition in pnv_reset to be removed for now, we can add it later for mpipl purpose if needed. [1]: https://lore.kernel.org/qemu-devel/[email protected]/ Thanks, - Aditya G
