[PATCH v4 2/3] hw/i386: Update the EPYC topology to use socket/dies/core/thread model

[Babu Moger]

Update the EPYC topology to use socket/dies/core/thread model. The EPYC
model does not use the smp dies to build the topology. Instead, it uses
numa nodes to build the topology. Internally both are similar concept
which divides the cores on L3 boundary. Combining both into one terminology
makes it simple to program.

Add a new check to error out when smp dies are not provided when EPYC
model is numa configured. Next task is to remove node_id, nr_nodes and
nodes_per_pkg from EPYC topology which will be done in next patch.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 hw/i386/x86.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 67bee1bcb8..e90c42d2fc 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -138,6 +138,14 @@ void x86_cpus_init(X86MachineState *x86ms, int 
default_cpu_version)
 
     /* Check for apicid encoding */
     if (cpu_x86_use_epyc_apic_id_encoding(ms->cpu_type)) {
+        if ((ms->numa_state->num_nodes > 0) &&
+            ms->numa_state->num_nodes != (ms->smp.sockets * x86ms->smp_dies)) {
+            error_setg(&error_fatal, "Numa configuration here requires smp "
+                       "'dies' parameter. Configure the cpu topology properly "
+                       "with max_cpus = sockets * dies * cores * threads. Dies"
+                       " is equivalent to number of numa nodes in a socket.");
+            return;
+        }
         x86_set_epyc_topo_handlers(ms);
     }