Currently powerpc pnv machines doesnt respect `-dtb`
argument passed from outside. During cpu start content of
machine->fdt is overwritten by `pnv_dt_create`.

This was previously found and fixed, during the discussion
for dumpdtb issue [1]. But reintroduced in MPIPL support
[2]. Saddly it skipped in the review phase [3].

Adding a functional test for checking the external dtb case
in powernv11.

[1] https://lore.kernel.org/all/20260323231612.GA2637687@ax162/
[2] https://lore.kernel.org/qemu-devel/20260310124619.3909045-8-adityag@linux.ibm.com/
[3] https://lore.kernel.org/qemu-devel/abAmBV7g_bGNw0Ax@shivang.upadyay/

Changelog
* V1: https://lore.kernel.org/all/20260623063156.1110370-1-shivangu@linux.ibm.com/
  - change dtb from power10 to power11
  - refactored pnv_reset code to not `load_device_tree` on each iteration.
  - added commit message body.

Shivang Upadhyay (2):
  ppc/pnv: avoid regenerating DTB if external DTB is present
  ppc/pnv: add test to verify external DTB is honored

 hw/ppc/pnv.c                           | 10 +++++++---
 tests/functional/ppc64/test_powernv.py | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)

-- 
2.54.0