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[RFC PATCH v3 3/9] hw/arm/virt: Add cpu-map to device tree
From: |
Yanan Wang |
Subject: |
[RFC PATCH v3 3/9] hw/arm/virt: Add cpu-map to device tree |
Date: |
Sun, 16 May 2021 18:28:54 +0800 |
From: Andrew Jones <drjones@redhat.com>
Support device tree CPU topology descriptions.
In accordance with the Devicetree Specification, the Linux Doc
"arm/cpus.yaml" requires that cpus and cpu nodes in the DT are
present. And we meet the requirement by creating /cpus/cpu@*
nodes for members within ms->smp.cpus.
Correspondingly, we should also create subnodes in cpu-map for
the present cpus, each of which relates to an unique cpu node.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Co-developed-by: Yanan Wang <wangyanan55@huawei.com>
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
hw/arm/virt.c | 41 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 40 insertions(+), 1 deletion(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index c07841e3a4..e5dcdebdbc 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -349,10 +349,11 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms)
int cpu;
int addr_cells = 1;
const MachineState *ms = MACHINE(vms);
+ const VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
int smp_cpus = ms->smp.cpus;
/*
- * From Documentation/devicetree/bindings/arm/cpus.txt
+ * See Linux Documentation/devicetree/bindings/arm/cpus.yaml
* On ARM v8 64-bit systems value should be set to 2,
* that corresponds to the MPIDR_EL1 register size.
* If MPIDR_EL1[63:32] value is equal to 0 on all CPUs
@@ -405,8 +406,46 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms)
ms->possible_cpus->cpus[cs->cpu_index].props.node_id);
}
+ if (!vmc->no_cpu_topology) {
+ qemu_fdt_setprop_cell(ms->fdt, nodename, "phandle",
+ qemu_fdt_alloc_phandle(ms->fdt));
+ }
+
g_free(nodename);
}
+
+ if (!vmc->no_cpu_topology) {
+ /*
+ * See Linux Documentation/devicetree/bindings/cpu/cpu-topology.txt
+ * In a SMP system, the hierarchy of CPUs is defined through four
+ * entities that are used to describe the layout of physical CPUs
+ * in the system: socket/cluster/core/thread.
+ */
+ qemu_fdt_add_subnode(ms->fdt, "/cpus/cpu-map");
+
+ for (cpu = smp_cpus - 1; cpu >= 0; cpu--) {
+ char *cpu_path = g_strdup_printf("/cpus/cpu@%d", cpu);
+ char *map_path;
+
+ if (ms->smp.threads > 1) {
+ map_path = g_strdup_printf(
+ "/cpus/cpu-map/%s%d/%s%d/%s%d",
+ "socket", cpu / (ms->smp.cores * ms->smp.threads),
+ "core", (cpu / ms->smp.threads) % ms->smp.cores,
+ "thread", cpu % ms->smp.threads);
+ } else {
+ map_path = g_strdup_printf(
+ "/cpus/cpu-map/%s%d/%s%d",
+ "socket", cpu / ms->smp.cores,
+ "core", cpu % ms->smp.cores);
+ }
+ qemu_fdt_add_path(ms->fdt, map_path);
+ qemu_fdt_setprop_phandle(ms->fdt, map_path, "cpu", cpu_path);
+
+ g_free(map_path);
+ g_free(cpu_path);
+ }
+ }
}
static void fdt_add_its_gic_node(VirtMachineState *vms)
--
2.19.1
- RE: [RFC PATCH v3 4/9] hw/arm/virt: Initialize the present cpu members, (continued)
[RFC PATCH v3 9/9] hw/arm/virt: Add separate -smp parsing function for ARM machines, Yanan Wang, 2021/05/16
[RFC PATCH v3 8/9] hw/arm/virt-acpi-build: Generate PPTT table, Yanan Wang, 2021/05/16
[RFC PATCH v3 3/9] hw/arm/virt: Add cpu-map to device tree,
Yanan Wang <=
[RFC PATCH v3 6/9] hw/arm/virt-acpi-build: Use possible cpus in generation of MADT, Yanan Wang, 2021/05/16