Re: [PATCH v7 7/7] hw/i386/pc: Support hv-balloon

[David Hildenbrand]

On 28.08.23 18:48, Maciej S. Szmigiero wrote:
> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>
> Add the necessary plumbing for the hv-balloon driver to the PC machine.
>
> Co-developed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
> ---
>   hw/i386/Kconfig |  1 +
>   hw/i386/pc.c    | 22 ++++++++++++++++++++++
>   2 files changed, 23 insertions(+)
>
> diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
> index 9051083c1e78..349cf0d32fad 100644
> --- a/hw/i386/Kconfig
> +++ b/hw/i386/Kconfig
> @@ -45,6 +45,7 @@ config PC
>       select ACPI_VMGENID
>       select VIRTIO_PMEM_SUPPORTED
>       select VIRTIO_MEM_SUPPORTED
> +    select HV_BALLOON_SUPPORTED
>   
>   config PC_PCI
>       bool
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 54838c0c411d..d979479cab5e 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -28,6 +28,7 @@
>   #include "hw/i386/pc.h"
>   #include "hw/char/serial.h"
>   #include "hw/char/parallel.h"
> +#include "hw/hyperv/hv-balloon.h"
>   #include "hw/i386/topology.h"
>   #include "hw/i386/fw_cfg.h"
>   #include "hw/i386/vmport.h"
> @@ -93,6 +94,7 @@
>   #include "hw/i386/kvm/xen_evtchn.h"
>   #include "hw/i386/kvm/xen_gnttab.h"
>   #include "hw/i386/kvm/xen_xenstore.h"
> +#include "hw/mem/memory-device.h"
>   #include "sysemu/replay.h"
>   #include "target/i386/cpu.h"
>   #include "e820_memory_layout.h"
> @@ -1494,6 +1496,21 @@ static void pc_memory_unplug(HotplugHandler *hotplug_dev,
>       error_propagate(errp, local_err);
>   }
>   
> +static void pc_hv_balloon_pre_plug(HotplugHandler *hotplug_dev,
> +                                   DeviceState *dev, Error **errp)
> +{
> +    /* The vmbus handler has no hotplug handler; we should never end up here. 
> */
> +    g_assert(!dev->hotplugged);
> +    memory_device_pre_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev), NULL,
> +                           errp);
> +}
> +
> +static void pc_hv_balloon_plug(HotplugHandler *hotplug_dev,
> +                               DeviceState *dev, Error **errp)
> +{
> +    memory_device_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
> +}
> +


Maybe we want to have hv_balloon_pre_plug() and hv_balloon_plug(), but 
this here should be good enough for now.

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb