diff options
Diffstat (limited to 'target/i386/cpu.c')
| -rw-r--r-- | target/i386/cpu.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 7a4484bb06..130391c840 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu/cutils.h" +#include "qemu/bitops.h" #include "cpu.h" #include "exec/exec-all.h" @@ -472,6 +473,8 @@ static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu, uint32_t *ecx, uint32_t *edx) { struct core_topology topo = {0}; + unsigned long nodes; + int shift; build_core_topology(cs->nr_cores, cpu->core_id, &topo); *eax = cpu->apic_id; @@ -504,7 +507,28 @@ static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu, * 2 Socket id * 1:0 Node id */ - *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << 2) | topo.node_id; + if (topo.num_nodes <= 4) { + *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << 2) | + topo.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 = topo.num_nodes - 1; + shift = find_last_bit(&nodes, 8); + *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << (shift + 1)) | + topo.node_id; + } *edx = 0; } |