Re: [Qemu-devel] [PATCH v4 2/2] tpm: extend TPM TIS with state migration support

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

Hi

On Thu, Mar 1, 2018 at 8:59 PM, Stefan Berger
<stefanb@linux.vnet.ibm.com> wrote:
> Extend the TPM TIS interface with state migration support.
>
> We need to synchronize with the backend thread to make sure that a command
> being processed by the external TPM emulator has completed and its
> response been received.
>
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> ---
>  hw/tpm/tpm_tis.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 53 insertions(+), 1 deletion(-)
>
> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> index 834eef7..5016d28 100644
> --- a/hw/tpm/tpm_tis.c
> +++ b/hw/tpm/tpm_tis.c
> @@ -902,9 +902,61 @@ static void tpm_tis_reset(DeviceState *dev)
>      tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size);
>  }
>
> +/* persistent state handling */
> +
> +static int tpm_tis_pre_save(void *opaque)
> +{
> +    TPMState *s = opaque;
> +    uint8_t locty = s->active_locty;
> +
> +    DPRINTF("tpm_tis: suspend: locty = %d : rw_offset = %u\n",

suspend -> pre_save ?

> +            locty, s->rw_offset);
> +#ifdef DEBUG_TIS
> +    tpm_tis_dump_state(opaque, 0);
> +#endif

To avoid dead code, you could write:

if (DEBUG_TIS) {
...
}


> +
> +    /*
> +     * Synchronize with backend completion.
> +     */
> +    tpm_backend_finish_sync(s->be_driver);
> +
> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_locty = {
> +    .name = "loc",

I would use a more descriptive name, such as "tpm-tis/locty"

> +    .version_id = 1,
> +    .minimum_version_id = 0,

It's the first version, make it all 0.

> +    .minimum_version_id_old = 0,

not needed

> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT32(state, TPMLocality),
> +        VMSTATE_UINT32(inte, TPMLocality),
> +        VMSTATE_UINT32(ints, TPMLocality),
> +        VMSTATE_UINT8(access, TPMLocality),
> +        VMSTATE_UINT32(sts, TPMLocality),
> +        VMSTATE_UINT32(iface_id, TPMLocality),
> +        VMSTATE_END_OF_LIST(),
> +    }
> +};
> +
>  static const VMStateDescription vmstate_tpm_tis = {
>      .name = "tpm",

It's time to use a more specific name "tpm-tis" ?

> -    .unmigratable = 1,
> +    .version_id = 1,
> +    .minimum_version_id = 0,

It's the first version, make it all 0.

> +    .minimum_version_id_old = 0,

not needed

> +    .pre_save  = tpm_tis_pre_save,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_BUFFER(buffer, TPMState),
> +        VMSTATE_UINT16(rw_offset, TPMState),
> +        VMSTATE_UINT8(active_locty, TPMState),
> +        VMSTATE_UINT8(aborting_locty, TPMState),
> +        VMSTATE_UINT8(next_locty, TPMState),
> +
> +        VMSTATE_STRUCT_ARRAY(loc, TPMState, TPM_TIS_NUM_LOCALITIES, 1,
> +                             vmstate_locty, TPMLocality),
> +
> +        VMSTATE_END_OF_LIST()
> +    }
>  };
>
>  static Property tpm_tis_properties[] = {
> --
> 2.5.5
>
>

looks good otherwise

-- 
Marc-André Lureau