On 6/20/25 2:57 PM, Igor Mammedov wrote:
> On Mon, 16 Jun 2025 11:46:49 +0200
> Eric Auger <eric.au...@redhat.com> wrote:
>
>> QEMU will notify the OS about PCI hotplug/hotunplug events through
>> GED interrupts. Let the GED device handle a new PCI hotplug event.
>> On its occurrence it calls the \\_SB.PCI0.PCNT method with the BLCK
>> mutex held.
>>
>> The GED device uses a dedicated MMIO region that will be mapped
>> by the machine code.
>
>> At this point the GED still does not support PCI device hotplug in
>> its TYPE_HOTPLUG_HANDLER implementation. This will come in a
>> subsequent patch.
> looks out of order, perhaps it should be before this patch
done, swapped both patches.
Eric
>
>> Signed-off-by: Eric Auger <eric.au...@redhat.com>
>>
>> ---
>> v2 -> v3:
>> - pcihp_init and reset are put in ged code instead of machine code
>> (Igor)
>>
>> v1 -> v2:
>> - Introduce ACPI_PCIHP_REGION_NAME
>> ---
>> include/hw/acpi/generic_event_device.h | 4 ++++
>> hw/acpi/generic_event_device.c | 26 ++++++++++++++++++++++++++
>> hw/acpi/pcihp.c | 1 -
>> 3 files changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/hw/acpi/generic_event_device.h
>> b/include/hw/acpi/generic_event_device.h
>> index f5ffa67a39..ec8e1abe0a 100644
>> --- a/include/hw/acpi/generic_event_device.h
>> +++ b/include/hw/acpi/generic_event_device.h
>> @@ -102,6 +102,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
>> #define ACPI_GED_PWR_DOWN_EVT 0x2
>> #define ACPI_GED_NVDIMM_HOTPLUG_EVT 0x4
>> #define ACPI_GED_CPU_HOTPLUG_EVT 0x8
>> +#define ACPI_GED_PCI_HOTPLUG_EVT 0x10
>>
>> typedef struct GEDState {
>> MemoryRegion evt;
>> @@ -109,6 +110,8 @@ typedef struct GEDState {
>> uint32_t sel;
>> } GEDState;
>>
>> +#define ACPI_PCIHP_REGION_NAME "pcihp container"
>> +
>> struct AcpiGedState {
>> SysBusDevice parent_obj;
>> MemHotplugState memhp_state;
>> @@ -116,6 +119,7 @@ struct AcpiGedState {
>> CPUHotplugState cpuhp_state;
>> MemoryRegion container_cpuhp;
>> AcpiPciHpState pcihp_state;
>> + MemoryRegion container_pcihp;
>> GEDState ged_state;
>> uint32_t ged_event_bitmap;
>> qemu_irq irq;
>> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
>> index ef1c1ec51f..b4eefb0106 100644
>> --- a/hw/acpi/generic_event_device.c
>> +++ b/hw/acpi/generic_event_device.c
>> @@ -12,6 +12,7 @@
>> #include "qemu/osdep.h"
>> #include "qapi/error.h"
>> #include "hw/acpi/acpi.h"
>> +#include "hw/acpi/pcihp.h"
>> #include "hw/acpi/generic_event_device.h"
>> #include "hw/pci/pci.h"
>> #include "hw/irq.h"
>> @@ -27,6 +28,7 @@ static const uint32_t ged_supported_events[] = {
>> ACPI_GED_PWR_DOWN_EVT,
>> ACPI_GED_NVDIMM_HOTPLUG_EVT,
>> ACPI_GED_CPU_HOTPLUG_EVT,
>> + ACPI_GED_PCI_HOTPLUG_EVT,
>> };
>>
>> /*
>> @@ -122,6 +124,12 @@ void build_ged_aml(Aml *table, const char *name,
>> HotplugHandler *hotplug_dev,
>> aml_notify(aml_name("\\_SB.NVDR"),
>> aml_int(0x80)));
>> break;
>> + case ACPI_GED_PCI_HOTPLUG_EVT:
>> + aml_append(if_ctx,
>> + aml_acquire(aml_name("\\_SB.PCI0.BLCK"),
>> 0xFFFF));
>> + aml_append(if_ctx, aml_call0("\\_SB.PCI0.PCNT"));
>> + aml_append(if_ctx,
>> aml_release(aml_name("\\_SB.PCI0.BLCK")));
>> + break;
>> default:
>> /*
>> * Please make sure all the events in ged_supported_events[]
>> @@ -300,6 +308,8 @@ static void acpi_ged_send_event(AcpiDeviceIf *adev,
>> AcpiEventStatusBits ev)
>> sel = ACPI_GED_NVDIMM_HOTPLUG_EVT;
>> } else if (ev & ACPI_CPU_HOTPLUG_STATUS) {
>> sel = ACPI_GED_CPU_HOTPLUG_EVT;
>> + } else if (ev & ACPI_PCI_HOTPLUG_STATUS) {
>> + sel = ACPI_GED_PCI_HOTPLUG_EVT;
>> } else {
>> /* Unknown event. Return without generating interrupt. */
>> warn_report("GED: Unsupported event %d. No irq injected", ev);
>> @@ -433,6 +443,12 @@ static void acpi_ged_realize(DeviceState *dev, Error
>> **errp)
>> cpu_hotplug_hw_init(&s->container_cpuhp, OBJECT(dev),
>> &s->cpuhp_state, 0);
>> break;
>> + case ACPI_GED_PCI_HOTPLUG_EVT:
>> + memory_region_init(&s->container_pcihp, OBJECT(dev),
>> + ACPI_PCIHP_REGION_NAME, ACPI_PCIHP_SIZE);
>> + sysbus_init_mmio(sbd, &s->container_pcihp);
>> + acpi_pcihp_init(OBJECT(s), &s->pcihp_state,
>> + s->pcihp_state.root, &s->container_pcihp, 0);
>> }
>> ged_events--;
>> }
>> @@ -474,6 +490,15 @@ static void acpi_ged_initfn(Object *obj)
>> sysbus_init_mmio(sbd, &ged_st->regs);
>> }
>>
>> +static void ged_reset(DeviceState *dev)
>> +{
>> + AcpiGedState *s = ACPI_GED(dev);
>> +
>> + if (s->pcihp_state.use_acpi_hotplug_bridge) {
>> + acpi_pcihp_reset(&s->pcihp_state);
>> + }
>> +}
>> +
>> static void acpi_ged_class_init(ObjectClass *class, const void *data)
>> {
>> DeviceClass *dc = DEVICE_CLASS(class);
>> @@ -488,6 +513,7 @@ static void acpi_ged_class_init(ObjectClass *class,
>> const void *data)
>> hc->plug = acpi_ged_device_plug_cb;
>> hc->unplug_request = acpi_ged_unplug_request_cb;
>> hc->unplug = acpi_ged_unplug_cb;
>> + device_class_set_legacy_reset(dc, ged_reset);
>>
>> adevc->ospm_status = acpi_ged_ospm_status;
>> adevc->send_event = acpi_ged_send_event;
>> diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
>> index e79a24b821..36492aa0d9 100644
>> --- a/hw/acpi/pcihp.c
>> +++ b/hw/acpi/pcihp.c
>> @@ -43,7 +43,6 @@
>> #include "qobject/qnum.h"
>> #include "trace.h"
>>
>> -#define ACPI_PCIHP_SIZE 0x0018
>> #define PCI_UP_BASE 0x0000
>> #define PCI_DOWN_BASE 0x0004
>> #define PCI_EJ_BASE 0x0008
