On 19/02/2025 22:34, Maciej S. Szmigiero wrote:
> External email: Use caution opening links or attachments
>
>
> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>
> This property allows configuring at runtime whether to transfer the
IIUC, in this patch it's not configurable at runtime, so let's drop "at
runtime".
> particular device state via multifd channels when live migrating that
> device.
>
> It defaults to AUTO, which means that VFIO device state transfer via
> multifd channels is attempted in configurations that otherwise support it.
>
> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
> ---
> hw/vfio/migration-multifd.c | 17 ++++++++++++++++-
> hw/vfio/pci.c | 3 +++
> include/hw/vfio/vfio-common.h | 2 ++
> 3 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c
> index 0cfa9d31732a..18a5ff964a37 100644
> --- a/hw/vfio/migration-multifd.c
> +++ b/hw/vfio/migration-multifd.c
> @@ -460,11 +460,26 @@ bool vfio_multifd_transfer_supported(void)
>
> bool vfio_multifd_transfer_enabled(VFIODevice *vbasedev)
> {
> - return false;
> + VFIOMigration *migration = vbasedev->migration;
> +
> + return migration->multifd_transfer;
> }
>
> bool vfio_multifd_transfer_setup(VFIODevice *vbasedev, Error **errp)
> {
> + VFIOMigration *migration = vbasedev->migration;
> +
> + /*
> + * Make a copy of this setting at the start in case it is changed
> + * mid-migration.
> + */
> + if (vbasedev->migration_multifd_transfer == ON_OFF_AUTO_AUTO) {
> + migration->multifd_transfer = vfio_multifd_transfer_supported();
> + } else {
> + migration->multifd_transfer =
> + vbasedev->migration_multifd_transfer == ON_OFF_AUTO_ON;
> + }
Making a copy of this value is only relevant for the next patch where
it's turned mutable, so let's move this code to patch #32.
Thanks.
> +
> if (vfio_multifd_transfer_enabled(vbasedev) &&
> !vfio_multifd_transfer_supported()) {
> error_setg(errp,
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 89d900e9cf0c..184ff882f9d1 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3377,6 +3377,9 @@ static const Property vfio_pci_dev_properties[] = {
> VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false),
> DEFINE_PROP_ON_OFF_AUTO("enable-migration", VFIOPCIDevice,
> vbasedev.enable_migration, ON_OFF_AUTO_AUTO),
> + DEFINE_PROP_ON_OFF_AUTO("x-migration-multifd-transfer", VFIOPCIDevice,
> + vbasedev.migration_multifd_transfer,
> + ON_OFF_AUTO_AUTO),
> DEFINE_PROP_BOOL("migration-events", VFIOPCIDevice,
> vbasedev.migration_events, false),
> DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false),
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index ba851917f9fc..3006931accf6 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -91,6 +91,7 @@ typedef struct VFIOMigration {
> uint64_t mig_flags;
> uint64_t precopy_init_size;
> uint64_t precopy_dirty_size;
> + bool multifd_transfer;
> VFIOMultifd *multifd;
> bool initial_data_sent;
>
> @@ -153,6 +154,7 @@ typedef struct VFIODevice {
> bool no_mmap;
> bool ram_block_discard_allowed;
> OnOffAuto enable_migration;
> + OnOffAuto migration_multifd_transfer;
> bool migration_events;
> VFIODeviceOps *ops;
> unsigned int num_irqs;