[PULL 5/6] hw/ppc/spapr: Add the "rtas-version" property to /rtas

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

From: Showta Ishizaki <zakinko@snowrabbit.org>

PAPR requires every property listed in its table of /rtas device tree
properties to be present before the OS is booted (R-7.2.6-3 and Table
20 in PAPR v10.60; the same requirement is in LoPAR 2.9 and LoPAPR
1.1). One of them is "rtas-version", an integer encoding of the RTAS
interface version, and PAPR says it describes version 1 of that
interface.

spapr_dt_rtas() sets "rtas-size", "rtas-error-log-max" and
"rtas-event-scan-rate" but never "rtas-version", so a client that reads
it finds no RTAS: NetBSD's RTAS driver fails to attach when the
property is absent.

Set it to 1, the version PAPR describes.

Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Tested-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Showta Ishizaki <zakinko@snowrabbit.org>
Link: https://lore.kernel.org/qemu-devel/20261005161859.3119EC92F0@bambi.snowrabbit.org
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
---
 include/hw/ppc/spapr.h | 3 +++
 hw/ppc/spapr.c         | 1 +
 2 files changed, 4 insertions(+)

diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 9acda15d4f..98a9099b8a 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -830,6 +830,9 @@ void spapr_load_rtas(SpaprMachineState *spapr, void *fdt, hwaddr addr);
 
 #define RTAS_EVENT_SCAN_RATE    1
 
+/* RTAS interface version, as defined by PAPR v10.60 Table 20 */
+#define RTAS_VERSION            1
+
 /* This helper should be used to encode interrupt specifiers when the related
  * "interrupt-controller" node has its "#interrupt-cells" property set to 2 (ie,
  * VIO devices, RTAS event sources and PHBs).
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 6d99464486..8a1b5b37b6 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1068,6 +1068,7 @@ static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
                           RTAS_ERROR_LOG_MAX));
     _FDT(fdt_setprop_cell(fdt, rtas, "rtas-event-scan-rate",
                           RTAS_EVENT_SCAN_RATE));
+    _FDT(fdt_setprop_cell(fdt, rtas, "rtas-version", RTAS_VERSION));
 
     g_assert(msi_nonbroken);
     _FDT(fdt_setprop(fdt, rtas, "ibm,change-msix-capable", NULL, 0));
-- 
2.52.0