Re: [PATCH v6 24/36] vfio/migration: Multifd setup/cleanup functions and associated VFIOMultifd

["Cédric Le Goater" <clg@redhat.com>]

On 3/4/25 23:03, Maciej S. Szmigiero wrote:
> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
> 
> Add multifd setup/cleanup functions and an associated VFIOMultifd data
> structure that will contain most of the receive-side data together
> with its init/cleanup methods.
> 
> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/migration-multifd.c   | 44 +++++++++++++++++++++++++++++++++++
>   hw/vfio/migration-multifd.h   |  4 ++++
>   include/hw/vfio/vfio-common.h |  3 +++
>   3 files changed, 51 insertions(+)
> 
> diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c
> index 79fae0b6296f..091dc43210ad 100644
> --- a/hw/vfio/migration-multifd.c
> +++ b/hw/vfio/migration-multifd.c
> @@ -32,8 +32,52 @@ typedef struct VFIODeviceStatePacket {
>       uint8_t data[0];
>   } QEMU_PACKED VFIODeviceStatePacket;
>   
> +typedef struct VFIOMultifd {
> +} VFIOMultifd;
> +
> +static VFIOMultifd *vfio_multifd_new(void)
> +{
> +    VFIOMultifd *multifd = g_new(VFIOMultifd, 1);
> +
> +    return multifd;
> +}
> +
> +static void vfio_multifd_free(VFIOMultifd *multifd)
> +{
> +    g_free(multifd);
> +}
> +
> +void vfio_multifd_cleanup(VFIODevice *vbasedev)
> +{
> +    VFIOMigration *migration = vbasedev->migration;
> +
> +    g_clear_pointer(&migration->multifd, vfio_multifd_free);
> +}
> +
>   bool vfio_multifd_transfer_supported(void)
>   {
>       return multifd_device_state_supported() &&
>           migrate_send_switchover_start();
>   }
> +
> +bool vfio_multifd_transfer_enabled(VFIODevice *vbasedev)
> +{
> +    return false;
> +}
> +
> +bool vfio_multifd_setup(VFIODevice *vbasedev, bool alloc_multifd, Error **errp)
> +{
> +    VFIOMigration *migration = vbasedev->migration;
> +
> +    if (!vfio_multifd_transfer_enabled(vbasedev)) {
> +        /* Nothing further to check or do */
> +        return true;
> +    }
> +
> +    if (alloc_multifd) {
> +        assert(!migration->multifd);
> +        migration->multifd = vfio_multifd_new();
> +    }
> +
> +    return true;
> +}
> diff --git a/hw/vfio/migration-multifd.h b/hw/vfio/migration-multifd.h
> index 1b60d5f67a1c..2a7a76164f29 100644
> --- a/hw/vfio/migration-multifd.h
> +++ b/hw/vfio/migration-multifd.h
> @@ -14,6 +14,10 @@
>   
>   #include "hw/vfio/vfio-common.h"
>   
> +bool vfio_multifd_setup(VFIODevice *vbasedev, bool alloc_multifd, Error **errp);
> +void vfio_multifd_cleanup(VFIODevice *vbasedev);
> +
>   bool vfio_multifd_transfer_supported(void);
> +bool vfio_multifd_transfer_enabled(VFIODevice *vbasedev);
>   
>   #endif
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index bf5d52087129..40382390692d 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -78,6 +78,8 @@ typedef struct VFIORegion {
>       uint8_t nr; /* cache the region number for debug */
>   } VFIORegion;
>   
> +typedef struct VFIOMultifd VFIOMultifd;
> +
>   typedef struct VFIOMigration {
>       struct VFIODevice *vbasedev;
>       VMChangeStateEntry *vm_state;
> @@ -89,6 +91,7 @@ typedef struct VFIOMigration {
>       uint64_t mig_flags;
>       uint64_t precopy_init_size;
>       uint64_t precopy_dirty_size;
> +    VFIOMultifd *multifd;
>       bool initial_data_sent;
>   
>       bool event_save_iterate_started;
>