On 2021/5/13 14:58, Andrew Jones wrote:
On Tue, Apr 13, 2021 at 04:07:41PM +0800, Yanan Wang wrote:
From: Andrew Jones <drjo...@redhat.com>
Support device tree CPU topology descriptions.
Signed-off-by: Andrew Jones <drjo...@redhat.com>
Signed-off-by: Yanan Wang <wangyana...@huawei.com>
---
hw/arm/virt.c | 41 ++++++++++++++++++++++++++++++++++++++++-
include/hw/arm/virt.h | 1 +
2 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 9f01d9041b..f4ae60ded9 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -352,10 +352,11 @@ 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
@@ -408,8 +409,45 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms)
ms->possible_cpus->cpus[cs->cpu_index].props.node_id);
}
+ if (ms->smp.cpus > 1 && !vmc->no_cpu_topology) {
We should probably always generate the cpu-map, like we agreed to always
generate the PPTT.
Ok, I will remove smp.cpus check for cpu-map too.
Single cpu node, corresponding to single cpu-map path also works.
If, for some reason, we don't want to generate the
cpu-map for uniprocessor systems, then we should actually be checking
ms->smp.maxcpus here (and below) to be sure it's uniprocessor.
Right, it's max cpus that ought to be checked but not smp cpus.
Thanks,
Yanan
Thanks,
drew
+ qemu_fdt_setprop_cell(ms->fdt, nodename, "phandle",
+ qemu_fdt_alloc_phandle(ms->fdt));
+ }
+
g_free(nodename);
}
+
+ if (ms->smp.cpus > 1 && !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 = ms->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)
@@ -2769,6 +2807,7 @@ static void virt_machine_5_2_options(MachineClass *mc)
virt_machine_6_0_options(mc);
compat_props_add(mc->compat_props, hw_compat_5_2, hw_compat_5_2_len);
vmc->no_secure_gpio = true;
+ vmc->no_cpu_topology = true;
}
DEFINE_VIRT_MACHINE(5, 2)
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 921416f918..4a4b98e4a7 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -129,6 +129,7 @@ struct VirtMachineClass {
bool no_kvm_steal_time;
bool acpi_expose_flash;
bool no_secure_gpio;
+ bool no_cpu_topology;
};
struct VirtMachineState {
--
2.19.1
.
