pnv/mpipl: Enable MPIPL support

With all MPIPL support in place, export a "dump" node in device tree,
signifying that PowerNV QEMU platform supports MPIPL

Also, export fw-load-area dt node, which has details about where the
kernel & initrd were loaded, so that kernel can verify whether the
kernel/initrd images were loaded within the boot memory region. QEMU
just exports these details in fw-load-area, the check for boot memory
region is done in kernel.

Since now device tree can change at pnv_reset, hence regenerate device
tree during pnv_reset

Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Tested-by: Shivang Upadhyay <shivangu@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20260424083837.214947-9-adityag@linux.ibm.com
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>

diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 48f49bef825153ec6a024ea699802abc3ed2ad3f..89096f9a8431906dd2476882cb5730268050d898 100644 (file)
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -54,6 +54,7 @@
 #include "hw/ppc/pnv_chip.h"
 #include "hw/ppc/pnv_xscom.h"
 #include "hw/ppc/pnv_pnor.h"
+#include "hw/ppc/pnv_mpipl.h"
 
 #include "hw/isa/isa.h"
 #include "hw/char/serial-isa.h"
@@ -672,6 +673,39 @@ static void pnv_dt_power_mgt(PnvMachineState *pnv, void *fdt)
     _FDT(fdt_setprop_cell(fdt, off, "ibm,enabled-stop-levels", 0xc0000000));
 }
 
+static void pnv_dt_mpipl_dump(PnvMachineState *pnv, void *fdt)
+{
+    int off;
+
+    /*
+     * Add "dump" node so kernel knows MPIPL (aka fadump) is supported
+     *
+     * Note: This is only needed to be done since we are passing device tree to
+     * opal
+     *
+     * In case HDAT is supported in future, then opal can add these nodes by
+     * itself based on system attribute having MPIPL_SUPPORTED bit set
+     */
+    off = fdt_add_subnode(fdt, 0, "ibm,opal");
+    if (off == -FDT_ERR_EXISTS) {
+        off = fdt_path_offset(fdt, "/ibm,opal");
+    }
+
+    _FDT(off);
+    off = fdt_add_subnode(fdt, off, "dump");
+    _FDT(off);
+    _FDT((fdt_setprop_string(fdt, off, "compatible", "ibm,opal-dump")));
+
+    /* Add kernel and initrd as fw-load-area */
+    uint64_t fw_load_area[4] = {
+        cpu_to_be64(KERNEL_LOAD_ADDR), cpu_to_be64(KERNEL_MAX_SIZE),
+        cpu_to_be64(INITRD_LOAD_ADDR), cpu_to_be64(INITRD_MAX_SIZE)
+    };
+
+    _FDT((fdt_setprop(fdt, off, "fw-load-area",
+                    fw_load_area, sizeof(fw_load_area))));
+}
+
 static void *pnv_dt_create(MachineState *machine)
 {
     PnvMachineClass *pmc = PNV_MACHINE_GET_CLASS(machine);
@@ -734,6 +768,9 @@ static void *pnv_dt_create(MachineState *machine)
         pmc->dt_power_mgt(pnv, fdt);
     }
 
+    /* Advertise support for MPIPL */
+    pnv_dt_mpipl_dump(pnv, fdt);
+
     return fdt;
 }
 
@@ -765,6 +802,10 @@ static void pnv_reset(MachineState *machine, ResetType type)
         mpipl_write_succeeded = do_mpipl_write(pnv);
     }
 
+    /* Regenerate device tree */
+    fdt = pnv_dt_create(machine);
+    _FDT((fdt_pack(fdt)));
+
     /*
      * If it's a MPIPL boot, add the "mpipl-boot" property, and reset the
      * boolean for MPIPL boot for next boot
@@ -814,8 +855,11 @@ static void pnv_reset(MachineState *machine, ResetType type)
                 sizeof(proc_area));
     }
 
-    fdt = machine->fdt;
     cpu_physical_memory_write(PNV_FDT_ADDR, fdt, fdt_totalsize(fdt));
+
+    /* Free previous device tree set by pnv_init/reset/machine_init_done */
+    g_free(machine->fdt);
+    machine->fdt = fdt;
 }
 
 static ISABus *pnv_chip_power8_isa_create(PnvChip *chip, Error **errp)