Re: [Qemu-devel] [PATCH v4 5/8] hw/arm/virt: Enable device memory cold/hot plug with ACPI boot

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 9 Apr 2019 11:29:32 +0100
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:

> This initializes the GED device with base memory and irq, configures
> ged memory hotplug event and builds the corresponding aml code. GED
> irq routing to Guest is also enabled. With this, both hot and cold
> plug of device memory is enabled now for Guest with ACPI boot.
> 
> Memory cold plug support with Guest DT boot is not yet supported.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  default-configs/arm-softmmu.mak |  2 ++
>  hw/arm/virt-acpi-build.c        |  9 ++++++
>  hw/arm/virt.c                   | 61 +++++++++++++++++++++++++++++++++++++++--
>  include/hw/arm/virt.h           |  4 +++
>  4 files changed, 73 insertions(+), 3 deletions(-)
> 
> diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
> index 9f4b803..c9a9b34 100644
> --- a/default-configs/arm-softmmu.mak
> +++ b/default-configs/arm-softmmu.mak
> @@ -163,3 +163,5 @@ CONFIG_LSI_SCSI_PCI=y
>  
>  CONFIG_MEM_DEVICE=y
>  CONFIG_DIMM=y
> +CONFIG_ACPI_MEMORY_HOTPLUG=y
> +CONFIG_ACPI_HW_REDUCED=y
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index bf9c0bc..1ad394b 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -40,6 +40,8 @@
>  #include "hw/loader.h"
>  #include "hw/hw.h"
>  #include "hw/acpi/aml-build.h"
> +#include "hw/acpi/memory_hotplug.h"
> +#include "hw/acpi/generic_event_device.h"
>  #include "hw/pci/pcie_host.h"
>  #include "hw/pci/pci.h"
>  #include "hw/arm/virt.h"
> @@ -727,6 +729,7 @@ static void
>  build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
>      Aml *scope, *dsdt;
> +    MachineState *ms = MACHINE(vms);
>      const MemMapEntry *memmap = vms->memmap;
>      const int *irqmap = vms->irqmap;
>  
> @@ -753,6 +756,12 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>                         (irqmap[VIRT_GPIO] + ARM_SPI_BASE));
>      acpi_dsdt_add_power_button(scope);
>  
> +    build_ged_aml(scope, "\\_SB."GED_DEVICE, HOTPLUG_HANDLER(vms->acpi_dev),
> +                  irqmap[VIRT_ACPI_GED] + ARM_SPI_BASE, AML_SYSTEM_MEMORY);
> +
> +    build_memory_hotplug_aml(scope, ms->ram_slots, "\\_SB", NULL,
> +                             AML_SYSTEM_MEMORY);
>
are you sure we should add these parts if acpi_device not present or ms->ram_slots == 0 ?

>      aml_append(dsdt, scope);
>  
>      /* copy AML table into ACPI tables blob and patch header there */

[...]

> +
>  static void create_gic(VirtMachineState *vms, qemu_irq *pic)
>  {
>      /* We create a standalone GIC */
> @@ -670,6 +707,8 @@ static void create_gic(VirtMachineState *vms, qemu_irq *pic)
>          pic[i] = qdev_get_gpio_in(gicdev, i);
>      }
>  
> +    vms->gsi = qemu_allocate_irqs(virt_gsi_handler, pic, NUM_IRQS);

Why do we need this "gsi" to begin with?

> +
>      fdt_add_gic_node(vms);
>  
>      if (type == 3 && vms->its) {
> @@ -1418,7 +1457,7 @@ static void machvirt_init(MachineState *machine)
>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(machine);
>      MachineClass *mc = MACHINE_GET_CLASS(machine);
>      const CPUArchIdList *possible_cpus;
> -    qemu_irq pic[NUM_IRQS];
> +    qemu_irq *pic;
>      MemoryRegion *sysmem = get_system_memory();
>      MemoryRegion *secure_sysmem = NULL;
>      int n, virt_max_cpus;
> @@ -1614,6 +1653,7 @@ static void machvirt_init(MachineState *machine)
>  
>      create_flash(vms, sysmem, secure_sysmem ? secure_sysmem : sysmem);
>  
> +    pic = g_new0(qemu_irq, NUM_IRQS);
>      create_gic(vms, pic);
>  
>      fdt_add_pmu_nodes(vms);
> @@ -1644,6 +1684,8 @@ static void machvirt_init(MachineState *machine)
>  
>      create_platform_bus(vms, pic);
>  
> +    vms->acpi_dev = create_acpi_ged(vms);

what if we start QEMU with -no-acpi?

>      vms->bootinfo.ram_size = machine->ram_size;
>      vms->bootinfo.kernel_filename = machine->kernel_filename;
>      vms->bootinfo.kernel_cmdline = machine->kernel_cmdline;
> @@ -1811,21 +1853,34 @@ static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)
>  static void virt_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
>                                   Error **errp)
>  {
> -    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> -        error_setg(errp, "memory cold/hot plug is not yet supported");
> +    VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> +    const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
> +
> +    if (is_nvdimm) {
> +        error_setg(errp, "nvdimm is not yet supported");
>          return;
>      }
>  
> +    if (!vms->acpi_dev) {
> +        error_setg(errp, "memory hotplug is not enabled: missing acpi device");
> +        return;
> +    }
> +
> +    hotplug_handler_pre_plug(HOTPLUG_HANDLER(vms->acpi_dev), dev, errp);
> +
>      pc_dimm_pre_plug(PC_DIMM(dev), MACHINE(hotplug_dev), NULL, errp);
>  }
>  
>  static void virt_memory_plug(HotplugHandler *hotplug_dev,
>                               DeviceState *dev, Error **errp)
>  {
> +    HotplugHandlerClass *hhc;
>      VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
>  
>      pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), NULL);
>  
> +    hhc = HOTPLUG_HANDLER_GET_CLASS(vms->acpi_dev);
> +    hhc->plug(HOTPLUG_HANDLER(vms->acpi_dev), dev, NULL);
>  }
>  
>  static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 507517c..9c6b0b1 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -77,6 +77,8 @@ enum {
>      VIRT_GPIO,
>      VIRT_SECURE_UART,
>      VIRT_SECURE_MEM,
> +    VIRT_PCDIMM_ACPI,
> +    VIRT_ACPI_GED,
>      VIRT_LOWMEMMAP_LAST,
>  };
>  
> @@ -132,6 +134,8 @@ typedef struct {
>      uint32_t iommu_phandle;
>      int psci_conduit;
>      hwaddr highest_gpa;
> +    DeviceState *acpi_dev;
> +    qemu_irq *gsi;
>  } VirtMachineState;
>  
>  #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM)