[for-5.0 4/4] spapr: Correct clamping of RMA to Node 0 size

[David Gibson]

The Real Mode Area (RMA) needs to fit within Node 0 in NUMA configurations.
We use a helper function spapr_node0_size() to calculate this.

But that function doesn't actually get the size of Node 0, it gets the
minimum size of all nodes, ever since b082d65a300 "spapr: Add a helper for
node0_size calculation".  That was added, apparently, because Node 0 in
qemu's terms might not have corresponded to Node 0 in PAPR terms (i.e. the
node with memory at address 0).

That might not have been the case at the time, but it *is* the case now
that qemu node 0 must have the lowest address, which is the node we need.
So, we can simplify this logic, folding it into spapr_rma_size(), the only
remaining caller.

Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
---
 hw/ppc/spapr.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 7efd4f2b85..6611f75bdf 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -295,20 +295,6 @@ static void spapr_populate_pa_features(SpaprMachineState 
*spapr,
     _FDT((fdt_setprop(fdt, offset, "ibm,pa-features", pa_features, pa_size)));
 }
 
-static hwaddr spapr_node0_size(MachineState *machine)
-{
-    if (machine->numa_state->num_nodes) {
-        int i;
-        for (i = 0; i < machine->numa_state->num_nodes; ++i) {
-            if (machine->numa_state->nodes[i].node_mem) {
-                return MIN(pow2floor(machine->numa_state->nodes[i].node_mem),
-                           machine->ram_size);
-            }
-        }
-    }
-    return machine->ram_size;
-}
-
 static void add_str(GString *s, const gchar *s1)
 {
     g_string_append_len(s, s1, strlen(s1) + 1);
@@ -2668,10 +2654,13 @@ static hwaddr spapr_rma_size(SpaprMachineState *spapr, 
Error **errp)
 {
     MachineState *machine = MACHINE(spapr);
     hwaddr rma_size = machine->ram_size;
-    hwaddr node0_size = spapr_node0_size(machine);
 
     /* RMA has to fit in the first NUMA node */
-    rma_size = MIN(rma_size, node0_size);
+    if (machine->numa_state->num_nodes) {
+        hwaddr node0_size = machine->numa_state->nodes[0].node_mem;
+
+        rma_size = MIN(rma_size, node0_size);
+    }
 
     /*
      * VRMA access is via a special 1TiB SLB mapping, so the RMA can
@@ -2688,6 +2677,11 @@ static hwaddr spapr_rma_size(SpaprMachineState *spapr, 
Error **errp)
         rma_size = MIN(rma_size, 16 * GiB);
     }
 
+    /*
+     * RMA size must be a power of 2
+     */
+    rma_size = pow2floor(rma_size);
+
     if (rma_size < (MIN_RMA_SLOF * MiB)) {
         error_setg(errp,
 "pSeries SLOF firmware requires >= %ldMiB guest RMA (Real Mode Area)",
-- 
2.23.0