[RFC,V4,11/33] arm/virt: Enhance GED framework to handle vCPU hotplug events

Commit Message

Salil Mehta Oct. 9, 2024, 3:17 a.m. UTC

During GED device creation at Virt Machine initialization, add a new vCPU
hotplug event to the existing set of supported GED device events. Additionally,
initialize the memory map for the vCPU hotplug *control device*, which will
provide an interface to exchange ACPI events between QEMU/VMM and the Guest
Kernel.

Signed-off-by: Salil Mehta <[e-mail]>
Reviewed-by: Gavin Shan <[e-mail]>
---
 hw/arm/virt.c         | 5 ++++-
 include/hw/arm/virt.h | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

Patch

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 822c7d3d14..3986f6d9fc 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -80,6 +80,7 @@ 
 #include "hw/mem/pc-dimm.h"
 #include "hw/mem/nvdimm.h"
 #include "hw/acpi/generic_event_device.h"
+#include "hw/acpi/cpu_hotplug.h"
 #include "hw/virtio/virtio-md-pci.h"
 #include "hw/virtio/virtio-iommu.h"
 #include "hw/char/pl011.h"
@@ -180,6 +181,7 @@  static const MemMapEntry base_memmap[] = {
     [VIRT_NVDIMM_ACPI] =        { 0x09090000, NVDIMM_ACPI_IO_LEN},
     [VIRT_PVTIME] =             { 0x090a0000, 0x00010000 },
     [VIRT_SECURE_GPIO] =        { 0x090b0000, 0x00001000 },
+    [VIRT_CPUHP_ACPI] =         { 0x090c0000, ACPI_CPU_HOTPLUG_REG_LEN},
     [VIRT_MMIO] =               { 0x0a000000, 0x00000200 },
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
     [VIRT_PLATFORM_BUS] =       { 0x0c000000, 0x02000000 },
@@ -677,7 +679,7 @@  static inline DeviceState *create_acpi_ged(VirtMachineState *vms)
     DeviceState *dev;
     MachineState *ms = MACHINE(vms);
     int irq = vms->irqmap[VIRT_ACPI_GED];
-    uint32_t event = ACPI_GED_PWR_DOWN_EVT;
+    uint32_t event = ACPI_GED_PWR_DOWN_EVT | ACPI_GED_CPU_HOTPLUG_EVT;
 
     if (ms->ram_slots) {
         event |= ACPI_GED_MEM_HOTPLUG_EVT;
@@ -693,6 +695,7 @@  static inline DeviceState *create_acpi_ged(VirtMachineState *vms)
 
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, vms->memmap[VIRT_ACPI_GED].base);
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 1, vms->memmap[VIRT_PCDIMM_ACPI].base);
+    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 3, vms->memmap[VIRT_CPUHP_ACPI].base);
     sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, qdev_get_gpio_in(vms->gic, irq));
 
     return dev;
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 362422413c..b5bfb75f71 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -78,6 +78,7 @@  enum {
     VIRT_PCDIMM_ACPI,
     VIRT_ACPI_GED,
     VIRT_NVDIMM_ACPI,
+    VIRT_CPUHP_ACPI,
     VIRT_PVTIME,
     VIRT_LOWMEMMAP_LAST,
 };