Co-developed-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
docs/system/loongarch/virt.rst | 31 +++++++++++++++
hw/loongarch/virt.c | 73 ++++++++++++++++++++++++++++------
target/loongarch/cpu.c | 12 ++++++
target/loongarch/cpu.h | 16 ++++++++
4 files changed, 119 insertions(+), 13 deletions(-)
diff --git a/docs/system/loongarch/virt.rst b/docs/system/loongarch/virt.rst
index 172fba079e..8daf60785f 100644
--- a/docs/system/loongarch/virt.rst
+++ b/docs/system/loongarch/virt.rst
@@ -28,6 +28,37 @@ The ``qemu-system-loongarch64`` provides emulation for virt
machine. You can specify the machine type ``virt`` and
cpu type ``la464``.
+CPU Topology
+------------
+
+The ``LA464`` type CPUs have the concept of Socket Core and Thread.
+
+For example:
+
+``-smp 1,maxcpus=M,sockets=S,cores=C,threads=T``
+
+The above parameters indicate that the machine has a maximum of ``M`` vCPUs and
+``S`` sockets, each socket has ``C`` cores, each core has ``T`` threads,
+and each thread corresponds to a vCPU.
+
+Then ``M`` ``S`` ``C`` ``T`` has the following relationship:
+
+``M = S * C * T``
+
+In the CPU topology relationship, When we know the ``socket_id`` ``core_id``
+and ``thread_id`` of the CPU, we can calculate its ``arch_id``:
+
+``arch_id = (socket_id * S) + (core_id * C) + (thread_id * T)``
Is there a spec or some other reference where all of this is described?
(or is that a made up just for QEMU?)
+
+Similarly, when we know the ``arch_id`` of the CPU,
+we can also get its ``socket_id`` ``core_id`` and ``thread_id``:
+
+``socket_id = arch_id / (C * T)``
+
+``core_id = (arch_id / T) % C``
+
+``thread_id = arch_id % T``
+
Boot options
------------
diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 9a635d1d3d..1ed5130edf 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -1143,9 +1143,9 @@ static void virt_init(MachineState *machine)
LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(machine);
int i;
hwaddr base, size, ram_size = machine->ram_size;
- const CPUArchIdList *possible_cpus;
MachineClass *mc = MACHINE_GET_CLASS(machine);
CPUState *cpu;
+ Object *cpuobj;
if (!cpu_model) {
cpu_model = LOONGARCH_CPU_TYPE_NAME("la464");
@@ -1163,13 +1163,30 @@ static void virt_init(MachineState *machine)
memory_region_add_subregion(&lvms->system_iocsr, 0, &lvms->iocsr_mem);
/* Init CPUs */
- possible_cpus = mc->possible_cpu_arch_ids(machine);
I'd keep this, and use below, it makes line shorter
- for (i = 0; i < possible_cpus->len; i++) {
- cpu = cpu_create(machine->cpu_type);
+ mc->possible_cpu_arch_ids(machine);
+ for (i = 0; i < machine->smp.cpus; i++) {
+ cpuobj = object_new(machine->cpu_type);
+ if (cpuobj == NULL) {
+ error_report("Fail to create object with type %s ",
+ machine->cpu_type);
+ exit(EXIT_FAILURE);
+ }
+
+ cpu = CPU(cpuobj);
cpu->cpu_index = i;
this probably should be in _pre_plug handler,
also see
(a15d2728a9aa pc: Init CPUState->cpu_index with index in possible_cpus[])
for why x86 does it.
machine->possible_cpus->cpus[i].cpu = cpu;
- lacpu = LOONGARCH_CPU(cpu);
+ lacpu = LOONGARCH_CPU(cpuobj);
lacpu->phy_id = machine->possible_cpus->cpus[i].arch_id;
Given above is derived from topo data set below, I'd move above above
to pre_plug time, and calculate/set it there based on topo data.
There is no point in setting both at the same place.
+ object_property_set_int(cpuobj, "socket-id",
+
machine->possible_cpus->cpus[i].props.socket_id,
+ NULL);
+ object_property_set_int(cpuobj, "core-id",
+ machine->possible_cpus->cpus[i].props.core_id,
+ NULL);
+ object_property_set_int(cpuobj, "thread-id",
+
machine->possible_cpus->cpus[i].props.thread_id,
+ NULL);
+ qdev_realize_and_unref(DEVICE(cpuobj), NULL, &error_fatal);
}
fdt_add_cpu_nodes(lvms);
fdt_add_memory_nodes(machine);
@@ -1286,6 +1303,35 @@ static void virt_initfn(Object *obj)
virt_flash_create(lvms);
}
+static int virt_get_arch_id_from_topo(MachineState *ms, LoongArchCPUTopo *topo)
+{
+ int arch_id, sock_vcpu_num, core_vcpu_num;
+
+ /*
+ * calculate total logical cpus across socket/core/thread.
+ * For more information on how to calculate the arch_id,
+ * you can refer to the CPU Topology chapter of the
+ * docs/system/loongarch/virt.rst document.
+ */
+ sock_vcpu_num = topo->socket_id * (ms->smp.threads * ms->smp.cores);
+ core_vcpu_num = topo->core_id * ms->smp.threads;
+
+ /* get vcpu-id(logical cpu index) for this vcpu from this topology */
+ arch_id = (sock_vcpu_num + core_vcpu_num) + topo->thread_id;
+
+ assert(arch_id >= 0 && arch_id < ms->possible_cpus->len);
+
+ return arch_id;
+}
+
+static void virt_get_topo_from_index(MachineState *ms,
+ LoongArchCPUTopo *topo, int index)
+{
+ topo->socket_id = index / (ms->smp.cores * ms->smp.threads);
+ topo->core_id = index / ms->smp.threads % ms->smp.cores;
+ topo->thread_id = index % ms->smp.threads;
+}
+
static bool memhp_type_supported(DeviceState *dev)
{
/* we only support pc dimm now */
@@ -1385,8 +1431,9 @@ static HotplugHandler
*virt_get_hotplug_handler(MachineState *machine,
static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)
{
- int n;
+ int n, arch_id;
unsigned int max_cpus = ms->smp.max_cpus;
+ LoongArchCPUTopo topo;
if (ms->possible_cpus) {
assert(ms->possible_cpus->len == max_cpus);
@@ -1397,17 +1444,17 @@ static const CPUArchIdList
*virt_possible_cpu_arch_ids(MachineState *ms)
sizeof(CPUArchId) * max_cpus);
ms->possible_cpus->len = max_cpus;
for (n = 0; n < ms->possible_cpus->len; n++) {
+ virt_get_topo_from_index(ms, &topo, n);
+ arch_id = virt_get_arch_id_from_topo(ms, &topo);
+ ms->possible_cpus->cpus[n].vcpus_count = 1;
ms->possible_cpus->cpus[n].type = ms->cpu_type;
- ms->possible_cpus->cpus[n].arch_id = n;
-
+ ms->possible_cpus->cpus[n].arch_id = arch_id;
ms->possible_cpus->cpus[n].props.has_socket_id = true;
- ms->possible_cpus->cpus[n].props.socket_id =
- n / (ms->smp.cores * ms->smp.threads);
+ ms->possible_cpus->cpus[n].props.socket_id = topo.socket_id;
ms->possible_cpus->cpus[n].props.has_core_id = true;
- ms->possible_cpus->cpus[n].props.core_id =
- n / ms->smp.threads % ms->smp.cores;
+ ms->possible_cpus->cpus[n].props.core_id = topo.core_id;
ms->possible_cpus->cpus[n].props.has_thread_id = true;
- ms->possible_cpus->cpus[n].props.thread_id = n % ms->smp.threads;
+ ms->possible_cpus->cpus[n].props.thread_id = topo.thread_id;
}
return ms->possible_cpus;
}
diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index 57cc4f314b..a99e22094e 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -16,6 +16,7 @@
#include "kvm/kvm_loongarch.h"
#include "exec/exec-all.h"
#include "cpu.h"
+#include "hw/qdev-properties.h"
#include "internals.h"
#include "fpu/softfloat-helpers.h"
#include "cpu-csr.h"
@@ -725,6 +726,7 @@ static void loongarch_cpu_init(Object *obj)
timer_init_ns(&cpu->timer, QEMU_CLOCK_VIRTUAL,
&loongarch_constant_timer_cb, cpu);
#endif
+ cpu->phy_id = UNSET_PHY_ID;
#endif
}
@@ -823,6 +825,14 @@ static int64_t loongarch_cpu_get_arch_id(CPUState *cs)
}
#endif
+static Property loongarch_cpu_properties[] = {
+ DEFINE_PROP_INT32("socket-id", LoongArchCPU, socket_id, 0),
+ DEFINE_PROP_INT32("core-id", LoongArchCPU, core_id, 0),
+ DEFINE_PROP_INT32("thread-id", LoongArchCPU, thread_id, 0),
+ DEFINE_PROP_INT32("node-id", LoongArchCPU, node_id,
CPU_UNSET_NUMA_NODE_ID),
+ DEFINE_PROP_END_OF_LIST()
+};
+
static void loongarch_cpu_class_init(ObjectClass *c, void *data)
{
LoongArchCPUClass *lacc = LOONGARCH_CPU_CLASS(c);
@@ -830,6 +840,7 @@ static void loongarch_cpu_class_init(ObjectClass *c, void
*data)
DeviceClass *dc = DEVICE_CLASS(c);
ResettableClass *rc = RESETTABLE_CLASS(c);
+ device_class_set_props(dc, loongarch_cpu_properties);
device_class_set_parent_realize(dc, loongarch_cpu_realizefn,
&lacc->parent_realize);
resettable_class_set_parent_phases(rc, NULL, loongarch_cpu_reset_hold,
NULL,
@@ -854,6 +865,7 @@ static void loongarch_cpu_class_init(ObjectClass *c, void
*data)
#ifdef CONFIG_TCG
cc->tcg_ops = &loongarch_tcg_ops;
#endif
+ dc->user_creatable = true;
}
static const gchar *loongarch32_gdb_arch_name(CPUState *cs)
diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 86c86c6c95..7472df0521 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -19,6 +19,12 @@
#include "cpu-csr.h"
#include "cpu-qom.h"
+/*
+ * CPU can't have 0xFFFFFFFF physical ID, use that value to distinguish
+ * that physical ID hasn't been set yet
pointer to CPU spec/doc here would be nice to have
+ */
+#define UNSET_PHY_ID 0xFFFFFFFF
+
#define IOCSRF_TEMP 0
#define IOCSRF_NODECNT 1
#define IOCSRF_MSI 2
@@ -390,6 +396,12 @@ typedef struct CPUArchState {
#endif
} CPULoongArchState;
+typedef struct LoongArchCPUTopo {
+ int32_t socket_id; /* socket-id of this VCPU */
+ int32_t core_id; /* core-id of this VCPU */
+ int32_t thread_id; /* thread-id of this VCPU */
+} LoongArchCPUTopo;
+
/**
* LoongArchCPU:
* @env: #CPULoongArchState
@@ -404,6 +416,10 @@ struct ArchCPU {
uint32_t phy_id;
OnOffAuto lbt;
OnOffAuto pmu;
+ int32_t socket_id; /* socket-id of this VCPU */
+ int32_t core_id; /* core-id of this VCPU */
+ int32_t thread_id; /* thread-id of this VCPU */
+ int32_t node_id; /* NUMA node of this VCPU */
/* 'compatible' string for this CPU for Linux device trees */
const char *dtb_compatible;