From: Salil Mehta <salil.me...@huawei.com> This change emits AML in DSDT to support vCPU deferred online-capability on arm/virt. It wires the CPU OSPM coordination paths so that CPUs which are administratively disabled at boot can be brought online later under policy, providing hotplug-like functionality without claiming full hotplug support.
The AML connects the CPUS scan method to a GED handler so QEMU and the
guest OSPM can coordinate CPU add/remove while the VM is running (e.g.
device-check, eject-request, _EJ0, CPU scan, _OST status reporting).
It also fixes an ACPI namespace load error:
AE_NOT_FOUND resolving \_SB.GED.PSCN
Error excerpt:
[ 0.070518] ACPI BIOS Error (bug): Object does not exist: GED_
[ 0.071457] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.GED.PSCN],
[ 0.073084] ACPI Error: AE_NOT_FOUND, During name lookup/catalog
Root cause was build order and naming: the PSCN handler must be created
under \_SB.GED using a short ACPI 'NameSeg', and referenced elsewhere by its
fully qualified path. The GED device (and PSCN) are now defined before the CPUS
AML, preventing the early lookup failure.
Notes:
* CPU enumeration remains from MADT (GICC). CPU0 is Enabled; other CPUs
may be Disabled but Online-Capable.
* Policy (which CPUs start disabled, later enabled) is administrative
and not decided by OSPM.
Tested: boot with EDK2/ACPI; no AE_NOT_FOUND for \_SB.GED.PSCN; generic CPU
devices register; sysfs topology group warnings do not occur.
DSDT.dsl (Not Working)
DSDT.dsl (Working)
---------------------
------------------
DefinitionBlock ("", "DSDT", 2, "BOCHS ", "BXPC ", 0x00000001)
DefinitionBlock ("", "DSDT", 2, "BOCHS ", "BXPC ", 0x00000001)
{ {
Scope (\_SB)
Scope (\_SB)
{ {
Scope (_SB)
Device (\_SB.GED)
{
{
Device (\_SB.CPUR)
Name (_HID, "ACPI0013"
{
Name (_UID, "GED")
[...]
Name (_CRS, ResourceTemplate ()
Device (\_SB.CPUS)
[...]
{
Method (_EVT, 1, Serialized)
Name (_HID, "ACPI0010")
{
Name (_CID, EisaId ("PNP0A05"))
Local0 = ESEL /* \_SB_.GED_.ESEL */
Method (CTFY, 2, NotSerialized)
If (((Local0 & 0x02) == 0x02))
{
{
[...]
Notify (PWRB, 0x80)
Method (CSTA, 1, Serialized)
}
{
[...]
If (((Local0 & 0x08) == 0x08))
Method (CEJ0, 1, Serialized)
{
{
\_SB.GED.PSCN ()
[...]
}
Method (CSCN, 0, Serialized)
}
{
}
[...]
Method (COST, 4, Serialized)
Scope (_SB)
{
{
[...]
Device (\_SB.CPUR)
Device (C000)
{
{
[...]
[...]
Device (\_SB.CPUS)
Device (C001)
{
{
Name (_HID, "ACPI0010")
[...]
Name (_CID, EisaId ("PNP0A05"))
Device (C002)
Method (CTFY, 2, NotSerialized)
{
{
[...]
[...]
Device (C003)
Method (CSTA, 1, Serialized)
{
{
[...]
[...]
Device (C004)
Method (CEJ0, 1, Serialized)
{
{
[...]
[...]
Device (C005)
Method (CSCN, 0, Serialized)
{
{
}
[...]
}
Method (COST, 4, Serialized)
{
Method (\_SB.GED.PSCN, 0, NotSerialized)
[...]
{
Device (C000)
\_SB.CPUS.CSCN ()
{
}
[...]
Device (C001)
Device (COM0)
{
{
[...]
[...]
Device (C002)
{
Device (\_SB.GED)
[...]
{
Device (C003)
Name (_HID, "ACPI0013")
{
Name (_UID, "GED")
[...]
Name (_CRS, ResourceTemplate ()
Device (C004)
{
{
[...]
[...]
OperationRegion (EREG, SystemMemory, 0x09080000, 0x04)
Device (C005)
Field (EREG, DWordAcc, NoLock, WriteAsZeros)
{
{
}
[...]
}
Method (_EVT, 1, Serialized)
Method (\_SB.GED.PSCN, 0, NotSerialized)
{
{
Local0 = ESEL
\_SB.CPUS.CSCN ()
If (((Local0 & 0x02) == 0x02))
}
{
Notify (PWRB, 0x80)
Device (COM0)
}
{
[...]
If (((Local0 & 0x08) == 0x08)) }
{ }
\_SB.GED.PSCN ()
}
}
}
Device (PWRB)
{
[...]
}
}
Signed-off-by: Salil Mehta <salil.me...@huawei.com>
---
hw/arm/virt-acpi-build.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 7c24dd6369..5e5acb3026 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -931,6 +931,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
VirtMachineState *vms)
VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
Aml *scope, *dsdt;
MachineState *ms = MACHINE(vms);
+ MachineClass *mc = MACHINE_GET_CLASS(ms);
const MemMapEntry *memmap = vms->memmap;
const int *irqmap = vms->irqmap;
AcpiTable table = { .sig = "DSDT", .rev = 2, .oem_id = vms->oem_id,
@@ -946,7 +947,30 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
VirtMachineState *vms)
* the RTC ACPI device at all when using UEFI.
*/
scope = aml_scope("\\_SB");
- acpi_dsdt_add_cpus(scope, vms);
+ if (vms->acpi_dev) {
+ build_ged_aml(scope, "\\_SB."GED_DEVICE,
+ HOTPLUG_HANDLER(vms->acpi_dev),
+ irqmap[VIRT_ACPI_GED] + ARM_SPI_BASE, AML_SYSTEM_MEMORY,
+ memmap[VIRT_ACPI_GED].base);
+ } else {
+ acpi_dsdt_add_gpio(scope, &memmap[VIRT_GPIO],
+ (irqmap[VIRT_GPIO] + ARM_SPI_BASE));
+ }
+
+ /*
+ * If the machine supports bringing administratively disabled vCPUs
+ * deferred-online under policy, build AML to coordinate the addition and
+ * removal of CPUs gracefully with the OSPM while the VM is running. This
+ * includes events such as device-check, eject-request, ejection (_EJ0),
+ * CPU scan, _OST status reporting, etc.
+ */
+ if (vms->acpi_dev && mc->has_online_capable_cpus) {
+ acpi_build_cpus_aml(scope, memmap[VIRT_ACPI_CPUPS].base, "\\_SB",
+ AML_GED_EVT_CPUPS_SCAN_METHOD);
+ } else {
+ acpi_dsdt_add_cpus(scope, vms);
+ }
+
acpi_dsdt_add_uart(scope, &memmap[VIRT_UART0],
(irqmap[VIRT_UART0] + ARM_SPI_BASE), 0);
if (vms->second_ns_uart_present) {
@@ -961,15 +985,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
VirtMachineState *vms)
(irqmap[VIRT_MMIO] + ARM_SPI_BASE),
0, NUM_VIRTIO_TRANSPORTS);
acpi_dsdt_add_pci(scope, memmap, irqmap[VIRT_PCIE] + ARM_SPI_BASE, vms);
- if (vms->acpi_dev) {
- build_ged_aml(scope, "\\_SB."GED_DEVICE,
- HOTPLUG_HANDLER(vms->acpi_dev),
- irqmap[VIRT_ACPI_GED] + ARM_SPI_BASE, AML_SYSTEM_MEMORY,
- memmap[VIRT_ACPI_GED].base);
- } else {
- acpi_dsdt_add_gpio(scope, &memmap[VIRT_GPIO],
- (irqmap[VIRT_GPIO] + ARM_SPI_BASE));
- }
if (vms->acpi_dev) {
uint32_t event = object_property_get_uint(OBJECT(vms->acpi_dev),
--
2.34.1
