Re: [Qemu-devel] [PATCH V4 03/10] Add persistent state handling to TPM TIS frontend driver

[Markus Armbruster <armbru@redhat.com>]

Stefan Berger <stefanb@linux.vnet.ibm.com> writes:

> This patch adds support for handling of persistent state to the TPM TIS
> frontend.
>
> The currently used buffer is determined (can only be in currently active
> locality and either be a read or a write buffer) and only that buffer's content
> is stored. The reverse is done when the state is restored from disk
> where the buffer's content are copied into the currently used buffer.
>
> To keep compatibility with existing Xen the VMStateDescription was adapted
> to be compatible with existing state. For that I am adding Andreas
> Niederl as an author to the file.
>
> v4:
>  - main thread releases the 'state' lock while periodically calling the
>    backends function that may request it to write data into block storage.
>
> v3:
>  - all functions prefixed with tis_
>  - while the main thread is waiting for an outstanding TPM command to finish,
>    it periodically does some work (writes data to the block storage)
>
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
>
> ---
>  hw/tpm_tis.c |  167 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 167 insertions(+)
>
> Index: qemu-git/hw/tpm_tis.c
> ===================================================================
> --- qemu-git.orig/hw/tpm_tis.c
> +++ qemu-git/hw/tpm_tis.c
[...]
> +static ISADeviceInfo tis_device_info = {
> +    .init         = tis_init,
> +    .qdev.name    = "tpm-tis",
> +    .qdev.size    = sizeof(TPMState),
> +    .qdev.no_user = 1,
> +    .qdev.vmsd    = &vmstate_tis,
> +    .qdev.reset   = tis_reset,
> +    .qdev.props = (Property[]) {
> +        DEFINE_PROP_UINT8("active_locality", TPMState,
> +                          active_locty, NO_LOCALITY),
> +        DEFINE_PROP_UINT32("irq", TPMState,
> +                           irq_num, TPM_TIS_IRQ),
> +        DEFINE_PROP_END_OF_LIST(),
> +    },
> +};
> +
> +
> +static void tis_register_device(void)
> +{
> +    isa_qdev_register(&tis_device_info);
> +}
> +
> +device_init(tis_register_device)

Why is this device no_user?