Re: [Qemu-devel] [PATCH v5.2 for 2.13 2/4] tpm: extend TPM TIS with state migration support

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* 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    | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  hw/tpm/trace-events |  1 +
>  2 files changed, 51 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/tpm/tpm_tis.c b/hw/tpm/tpm_tis.c
> index 2ac7e74..fec3d73 100644
> --- a/hw/tpm/tpm_tis.c
> +++ b/hw/tpm/tpm_tis.c
> @@ -894,9 +894,57 @@ 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;
> +
> +    trace_tpm_tis_pre_save(locty, s->rw_offset);
> +
> +    if (DEBUG_TIS) {
> +        tpm_tis_dump_state(opaque, 0);
> +    }
> +
> +    /*
> +     * Synchronize with backend completion.
> +     */
> +    tpm_backend_finish_sync(s->be_driver);
> +
> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_locty = {
> +    .name = "tpm-tis/locty",
> +    .version_id = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT32(state, TPMLocality),

I was a little worried with that being an enum, but I'm told
we're OK assuming enum's come out as UINT32's; so:

from the migration code side,

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> +        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",
> -    .unmigratable = 1,
> +    .name = "tpm-tis",
> +    .version_id = 1,
> +    .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[] = {
> diff --git a/hw/tpm/trace-events b/hw/tpm/trace-events
> index c5bfbf1..25bee0c 100644
> --- a/hw/tpm/trace-events
> +++ b/hw/tpm/trace-events
> @@ -50,3 +50,4 @@ tpm_tis_mmio_write_locty_seized(uint8_t locty, uint8_t active) "Locality %d seiz
>  tpm_tis_mmio_write_init_abort(void) "Initiating abort"
>  tpm_tis_mmio_write_lowering_irq(void) "Lowering IRQ"
>  tpm_tis_mmio_write_data2send(uint32_t value, unsigned size) "Data to send to TPM: 0x%08x (size=%d)"
> +tpm_tis_pre_save(uint8_t locty, uint32_t rw_offset) "locty: %d, rw_offset = %u"
> -- 
> 2.5.5
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK