[PATCH v5 2/3] spapr_numa: create a vcpu associativity helper

[Daniel Henrique Barboza]

The work to be done in h_home_node_associativity() intersects
with what is already done in spapr_numa_fixup_cpu_dt(). This
patch creates a new helper, spapr_numa_get_vcpu_assoc(), to
be used for both spapr_numa_fixup_cpu_dt() and
h_home_node_associativity().

While we're at it, use memcpy() instead of loop assignment
to created the returned array.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/spapr_numa.c    | 33 ++++++++++++++++++++-------------
 include/hw/ppc/spapr.h |  7 ++++++-
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
index 368c1a494d..674d2ee86d 100644
--- a/hw/ppc/spapr_numa.c
+++ b/hw/ppc/spapr_numa.c
@@ -71,31 +71,38 @@ void spapr_numa_write_associativity_dt(SpaprMachineState 
*spapr, void *fdt,
                       sizeof(spapr->numa_assoc_array[nodeid]))));
 }
 
-int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void *fdt,
-                            int offset, PowerPCCPU *cpu)
+static uint32_t *spapr_numa_get_vcpu_assoc(SpaprMachineState *spapr,
+                                           PowerPCCPU *cpu)
 {
-    uint vcpu_assoc_size = NUMA_ASSOC_SIZE + 1;
-    uint32_t vcpu_assoc[vcpu_assoc_size];
+    uint32_t *vcpu_assoc = g_malloc(VCPU_ASSOC_SIZE * sizeof(uint32_t));
     int index = spapr_get_vcpu_id(cpu);
-    int i;
+
+    g_assert(vcpu_assoc != NULL);
 
     /*
      * VCPUs have an extra 'cpu_id' value in ibm,associativity
      * compared to other resources. Increment the size at index
-     * 0, copy all associativity domains already set, then put
-     * cpu_id last.
+     * 0, put cpu_id last, then copy the remaining associativity
+     * domains.
      */
     vcpu_assoc[0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS + 1);
+    vcpu_assoc[VCPU_ASSOC_SIZE - 1] = cpu_to_be32(index);
+    memcpy(vcpu_assoc + 1, spapr->numa_assoc_array[cpu->node_id] + 1,
+           (VCPU_ASSOC_SIZE - 2) * sizeof(uint32_t));
 
-    for (i = 1; i <= MAX_DISTANCE_REF_POINTS; i++) {
-        vcpu_assoc[i] = spapr->numa_assoc_array[cpu->node_id][i];
-    }
+    return vcpu_assoc;
+}
+
+int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void *fdt,
+                            int offset, PowerPCCPU *cpu)
+{
+    g_autofree uint32_t *vcpu_assoc = NULL;
 
-    vcpu_assoc[vcpu_assoc_size - 1] = cpu_to_be32(index);
+    vcpu_assoc = spapr_numa_get_vcpu_assoc(spapr, cpu);
 
     /* Advertise NUMA via ibm,associativity */
-    return fdt_setprop(fdt, offset, "ibm,associativity",
-                       vcpu_assoc, sizeof(vcpu_assoc));
+    return fdt_setprop(fdt, offset, "ibm,associativity", vcpu_assoc,
+                       VCPU_ASSOC_SIZE * sizeof(uint32_t));
 }
 
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 9a63380801..e50a2672e3 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -107,13 +107,18 @@ typedef enum {
 
 /*
  * NUMA related macros. MAX_DISTANCE_REF_POINTS was taken
- * from Taken from Linux kernel arch/powerpc/mm/numa.h.
+ * from Linux kernel arch/powerpc/mm/numa.h. It represents the
+ * amount of associativity domains for non-CPU resources.
  *
  * NUMA_ASSOC_SIZE is the base array size of an ibm,associativity
  * array for any non-CPU resource.
+ *
+ * VCPU_ASSOC_SIZE represents the size of ibm,associativity array
+ * for CPUs, which has an extra element (vcpu_id) in the end.
  */
 #define MAX_DISTANCE_REF_POINTS    4
 #define NUMA_ASSOC_SIZE            (MAX_DISTANCE_REF_POINTS + 1)
+#define VCPU_ASSOC_SIZE            (NUMA_ASSOC_SIZE + 1)
 
 typedef struct SpaprCapabilities SpaprCapabilities;
 struct SpaprCapabilities {
-- 
2.26.2