Add support for cpuid leaf CPUID_8000_001E. Build the config that closely
match the underlying hardware. Please refer Processor Programming Reference
(PPR) for AMD Family 17h Model for more details.
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
target/i386/cpu.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 85 insertions(+)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 1dd060a..d9ccaad 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -415,6 +415,86 @@ static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, CPUState *cs,
(cache->complex_indexing ? CACHE_COMPLEX_IDX : 0);
}
+/* Data structure to hold the configuration info for a given core index */
+struct epyc_topo {
+ /* core complex id of the current core index */
+ int ccx_id;
+ /* new core id for this core index in the topology */
+ int core_id;
+ /* Node(or Die) id this core index */
+ int node_id;
+ /* Number of nodes(or dies) in this config, 0 based */
+ int num_nodes;
+};
+
+/*
+ * Build the configuration closely match the EPYC hardware
+ * nr_cores : Total number of cores in the config
+ * core_id : Core index of the current CPU
+ * topo : Data structure to hold all the config info for this core index
+ * Rules
+ * Max ccx in a node(die) = 2
+ * Max cores in a ccx = 4
+ * Max nodes(dies) = 4 (1, 2, 4)
+ * Max sockets = 2
+ * Maintain symmetry as much as possible
+ */
+static void epyc_build_topology(int nr_cores, int core_id,
+ struct epyc_topo *topo)
+{
+ int nodes = 1, cores_in_ccx;
+ int i;
+
+ /* Lets see if we can fit all the cores in one ccx */
+ if (nr_cores <= MAX_CORES_IN_CCX) {
+ cores_in_ccx = nr_cores;
+ goto topo;
+ }
+ /*
+ * Figure out the number of nodes(or dies) required to build
+ * this config. Max cores in a node is 8
+ */
+ for (i = nodes; i <= MAX_NODES_EPYC; i++) {
+ if (nr_cores <= (i * MAX_CORES_IN_NODE)) {
+ nodes = i;
+ break;
+ }
+ /* We support nodes 1, 2, 4 */
+ if (i == 3) {
+ continue;
+ }
+ }
+ /* Spread the cores accros all the CCXs and return max cores in a ccx */
+ cores_in_ccx = (nr_cores / (nodes * MAX_CCX)) +
+ ((nr_cores % (nodes * MAX_CCX)) ? 1 : 0);
+
+topo:
+ topo->node_id = core_id / (cores_in_ccx * MAX_CCX);
+ topo->ccx_id = (core_id % (cores_in_ccx * MAX_CCX)) / cores_in_ccx;
+ topo->core_id = core_id % cores_in_ccx;
+ /* num_nodes is 0 based, return n - 1 */
+ topo->num_nodes = nodes - 1;
+}
+
+/* Encode cache info for CPUID[8000001E] */
+static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu,
+ uint32_t *eax, uint32_t *ebx,
+ uint32_t *ecx, uint32_t *edx)
+{
+ struct epyc_topo topo = {0};
+
+ *eax = cpu->apic_id;
+ epyc_build_topology(cs->nr_cores, cpu->core_id, &topo);
+ if (cs->nr_threads - 1) {
+ *ebx = ((cs->nr_threads - 1) << 8) | (topo.node_id << 3) |
+ (topo.ccx_id << 2) | topo.core_id;
+ } else {
+ *ebx = (topo.node_id << 4) | (topo.ccx_id << 3) | topo.core_id;
+ }
+ *ecx = (topo.num_nodes << 8) | (cpu->socket_id << 2) | topo.node_id;
+ *edx = 0;
+}
+
/*
* Definitions of the hardcoded cache entries we expose:
* These are legacy cache values. If there is a need to change any
@@ -4108,6 +4188,11 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
break;
}
break;
+ case 0x8000001E:
+ assert(cpu->core_id <= 255);
+ encode_topo_cpuid8000001e(cs, cpu,
+ eax, ebx, ecx, edx);
+ break;
case 0xC0000000:
*eax = env->cpuid_xlevel2;
*ebx = 0;
--
1.8.3.1
