Re: [PATCH v5 4/7] hw/pci/pcie: Do not set HPC flag if acpihp is used

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 17 Jun 2021 21:07:36 +0200
Julia Suvorova <jusual@redhat.com> wrote:

> Instead of changing the hot-plug type in _OSC register, do not
> set the 'Hot-Plug Capable' flag. This way guest will choose ACPI
> hot-plug if it is preferred and leave the option to use SHPC with
> pcie-pci-bridge.
> 
> The ability to control hot-plug for each downstream port is retained,
> while 'hotplug=off' on the port means all hot-plug types are disabled.
> 
> Signed-off-by: Julia Suvorova <jusual@redhat.com>
> ---
>  include/hw/pci/pcie_port.h |  5 ++++-
>  hw/acpi/pcihp.c            |  8 ++++++++
>  hw/core/machine.c          |  1 -
>  hw/i386/pc_q35.c           | 11 +++++++++++
>  hw/pci/pcie.c              |  8 +++++++-
>  hw/pci/pcie_port.c         |  1 +
>  6 files changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h
> index bea8ecad0f..e25b289ce8 100644
> --- a/include/hw/pci/pcie_port.h
> +++ b/include/hw/pci/pcie_port.h
> @@ -57,8 +57,11 @@ struct PCIESlot {
>      /* Disable ACS (really for a pcie_root_port) */
>      bool        disable_acs;
>  
> -    /* Indicates whether hot-plug is enabled on the slot */
> +    /* Indicates whether any type of hot-plug is allowed on the slot */
>      bool        hotplug;
> +
> +    bool        native_hotplug;
> +
>      QLIST_ENTRY(PCIESlot) next;
>  };
>  
> diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
> index 5355618608..7a6bc1b31e 100644
> --- a/hw/acpi/pcihp.c
> +++ b/hw/acpi/pcihp.c
> @@ -31,6 +31,7 @@
>  #include "hw/pci/pci.h"
>  #include "hw/pci/pci_bridge.h"
>  #include "hw/pci/pci_host.h"
> +#include "hw/pci/pcie_port.h"
>  #include "hw/i386/acpi-build.h"
>  #include "hw/acpi/acpi.h"
>  #include "hw/pci/pci_bus.h"
> @@ -332,6 +333,13 @@ void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
>              object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
>              PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
>  
> +            /* Remove all hot-plug handlers if hot-plug is disabled on slot */
> +            if (object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT) &&
> +                !PCIE_SLOT(pdev)->hotplug) {
> +                qbus_set_hotplug_handler(BUS(sec), NULL);
> +                return;
> +            }
> +
>              qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev));
>              /* We don't have to overwrite any other hotplug handler yet */
>              assert(QLIST_EMPTY(&sec->child));
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 55b9bc7817..6ed0575d81 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -582,7 +582,6 @@ static void machine_set_memdev(Object *obj, const char *value, Error **errp)
>      ms->ram_memdev_id = g_strdup(value);
>  }
>  
> -
>  static void machine_init_notify(Notifier *notifier, void *data)
>  {
>      MachineState *machine = MACHINE(qdev_get_machine());
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 46a0f196f4..a0ec7964cc 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -37,6 +37,7 @@
>  #include "sysemu/kvm.h"
>  #include "hw/kvm/clock.h"
>  #include "hw/pci-host/q35.h"
> +#include "hw/pci/pcie_port.h"
>  #include "hw/qdev-properties.h"
>  #include "hw/i386/x86.h"
>  #include "hw/i386/pc.h"
> @@ -136,6 +137,7 @@ static void pc_q35_init(MachineState *machine)
>      ram_addr_t lowmem;
>      DriveInfo *hd[MAX_SATA_PORTS];
>      MachineClass *mc = MACHINE_GET_CLASS(machine);
> +    bool acpi_pcihp;
>  
>      /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
>       * and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
> @@ -236,6 +238,15 @@ static void pc_q35_init(MachineState *machine)
>      object_property_set_link(OBJECT(machine), PC_MACHINE_ACPI_DEVICE_PROP,
>                               OBJECT(lpc), &error_abort);
>  
> +    acpi_pcihp = object_property_get_bool(OBJECT(lpc),
> +                                          "acpi-pci-hotplug-with-bridge-support",
> +                                          NULL);
> +
> +    if (acpi_pcihp) {
> +        object_register_sugar_prop(TYPE_PCIE_SLOT, "enable-native-hotplug",
I'd s/enable-native-hotplug/native-hotplug/
which is more concise and consistent with other similar properties.
Perhaps Michael can fix it up on merge.

[...]

> +    DEFINE_PROP_BOOL("enable-native-hotplug", PCIESlot, native_hotplug, true),
>      DEFINE_PROP_END_OF_LIST()
>  };
>  

Otherwise looks good to me, so with this or without above nitpicking:
Reviewed-by: Igor Mammedov <imammedo@redhat.com>