apic_id contains all the information required to build CPUID_8000_001E. core_id and node_id is already part of apic_id generated by x86_topo_ids_from_apicid_epyc. Also remove the restriction on number bits on core_id and node_id.
Remove all the hardcoded values and replace with generalized fields. Refer the Processor Programming Reference (PPR) documentation available from the bugzilla Link below. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.mo...@amd.com> --- target/i386/cpu.c | 78 +++++++++++++++++++++++++---------------------------- 1 file changed, 37 insertions(+), 41 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 3733d9a279..166d2f2bde 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -388,57 +388,53 @@ static void encode_topo_cpuid8000001e(X86CPUTopoInfo *topo_info, X86CPU *cpu, { X86CPUTopoIDs topo_ids = {0}; unsigned long nodes = MAX(topo_info->nodes_per_pkg, 1); - int shift; x86_topo_ids_from_apicid_epyc(cpu->apic_id, topo_info, &topo_ids); *eax = cpu->apic_id; + /* + * CPUID_Fn8000001E_EBX [Core Identifiers] (CoreId) + * Read-only. Reset: 0000_XXXXh. + * See Core::X86::Cpuid::ExtApicId. + * Core::X86::Cpuid::CoreId_lthree[1:0]_core[3:0]_thread[1:0]; * CPUID_Fn8000001E_EBX - * 31:16 Reserved - * 15:8 Threads per core (The number of threads per core is - * Threads per core + 1) - * 7:0 Core id (see bit decoding below) - * SMT: - * 4:3 node id - * 2 Core complex id - * 1:0 Core id - * Non SMT: - * 5:4 node id - * 3 Core complex id - * 1:0 Core id + * Bits Description + * 31:16 Reserved. + * 15:8 ThreadsPerCore: threads per core. Read-only. Reset: XXh. + * The number of threads per core is ThreadsPerCore+1. + * 7:0 CoreId: core ID. Read-only. Reset: XXh. + * + * NOTE: CoreId is already part of apic_id. Just use it. We can + * use all the 8 bits to represent the core_id here. */ - *ebx = ((topo_info->threads_per_core - 1) << 8) | (topo_ids.node_id << 3) | - (topo_ids.core_id); + *ebx = ((topo_info->threads_per_core - 1) << 8) | (topo_ids.core_id & 0xFF); + /* + * CPUID_Fn8000001E_ECX [Node Identifiers] (NodeId) + * Read-only. Reset: 0000_0XXXh. + * Core::X86::Cpuid::NodeId_lthree[1:0]_core[3:0]_thread[1:0]; * CPUID_Fn8000001E_ECX - * 31:11 Reserved - * 10:8 Nodes per processor (Nodes per processor is number of nodes + 1) - * 7:0 Node id (see bit decoding below) - * 2 Socket id - * 1:0 Node id + * Bits Description + * 31:11 Reserved. + * 10:8 NodesPerProcessor: Node per processor. Read-only. Reset: XXXb. + * ValidValues: + * Value Description + * 000b 1 node per processor. + * 001b 2 nodes per processor. + * 010b Reserved. + * 011b 4 nodes per processor. + * 111b-100b Reserved. + * 7:0 NodeId: Node ID. Read-only. Reset: XXh. + * + * NOTE: Hardware reserves 3 bits for number of nodes per processor. + * But users can create more nodes than the actual hardware can + * support. To genaralize we can use all the upper 8 bits for nodes. + * NodeId is combination of node and socket_id which is already decoded + * in apic_id. Just use it by shifting. */ - if (nodes <= 4) { - *ecx = ((nodes - 1) << 8) | (topo_ids.pkg_id << 2) | topo_ids.node_id; - } else { - /* - * Node id fix up. Actual hardware supports up to 4 nodes. But with - * more than 32 cores, we may end up with more than 4 nodes. - * Node id is a combination of socket id and node id. Only requirement - * here is that this number should be unique accross the system. - * Shift the socket id to accommodate more nodes. We dont expect both - * socket id and node id to be big number at the same time. This is not - * an ideal config but we need to to support it. Max nodes we can have - * is 32 (255/8) with 8 cores per node and 255 max cores. We only need - * 5 bits for nodes. Find the left most set bit to represent the total - * number of nodes. find_last_bit returns last set bit(0 based). Left - * shift(+1) the socket id to represent all the nodes. - */ - nodes -= 1; - shift = find_last_bit(&nodes, 8); - *ecx = (nodes << 8) | (topo_ids.pkg_id << (shift + 1)) | - topo_ids.node_id; - } + *ecx = ((nodes - 1) << 8) | + ((cpu->apic_id >> apicid_node_offset_epyc(topo_info)) & 0xFF); *edx = 0; }
