[PATCH for-7.2 v3 10/20] hw/ppc: set machine->fdt in spapr machine

[Daniel Henrique Barboza <danielhb413@gmail.com>]

The pSeries machine never bothered with the common machine->fdt
attribute. We do all the FDT related work using spapr->fdt_blob.

We're going to introduce HMP commands to read and save the FDT, which
will rely on setting machine->fdt properly to work across all machine
archs/types.

Let's set machine->fdt in the two places where we manipulate the FDT:
spapr_machine_reset() and CAS.

spapr->fdt_blob is left untouched for now. To replace it with
machine->fdt, since we're migrating spapr->fdt_blob, we would need to
migrate machine->fdt as well. This is something that we would like to to
do keep our code simpler but it's a work we'll do another day.

Cc: Cédric Le Goater <clg@kaod.org>
Cc: qemu-ppc@nongnu.org
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/spapr.c       | 6 ++++++
 hw/ppc/spapr_hcall.c | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index bc9ba6e6dc..7031cf964a 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1713,6 +1713,12 @@ static void spapr_machine_reset(MachineState *machine)
     spapr->fdt_initial_size = spapr->fdt_size;
     spapr->fdt_blob = fdt;
 
+    /*
+     * Set the common machine->fdt pointer to enable support
+     * for 'dumpdtb' and 'info fdt' QMP/HMP commands.
+     */
+    machine->fdt = fdt;
+
     /* Set up the entry state */
     first_ppc_cpu->env.gpr[5] = 0;
 
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index a8d4a6bcf0..a53bfd76f4 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1256,6 +1256,14 @@ target_ulong do_client_architecture_support(PowerPCCPU *cpu,
     spapr->fdt_initial_size = spapr->fdt_size;
     spapr->fdt_blob = fdt;
 
+    /*
+     * Set the machine->fdt pointer again since we just freed
+     * it above (by freeing spapr->fdt_blob). We set this
+     * pointer to enable support for 'dumpdtb' and 'info fdt'
+     * QMP/HMP commands.
+     */
+    MACHINE(spapr)->fdt = fdt;
+
     return H_SUCCESS;
 }
 
-- 
2.37.2