Re: [PATCH v2 08/13] vtpmmgr: Shutdown more gracefully

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 5/6/21 9:59 AM, Jason Andryuk wrote:
> vtpmmgr uses the default, weak app_shutdown, which immediately calls the
> shutdown hypercall.  This short circuits the vtpmmgr clean up logic.  We
> need to perform the clean up to actually Flush our key out of the tpm.
> 
> Setting do_shutdown is one step in that direction, but vtpmmgr will most
> likely be waiting in tpmback_req_any.  We need to call shutdown_tpmback
> to cancel the wait inside tpmback and perform the shutdown.
> 
> Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
> Reviewed-by: Samuel Thibault <samuel.thibaut@xxxxxxxxxxxx>
> ---

Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>

>  stubdom/vtpmmgr/vtpmmgr.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/stubdom/vtpmmgr/vtpmmgr.c b/stubdom/vtpmmgr/vtpmmgr.c
> index 9fddaa24f8..46ea018921 100644
> --- a/stubdom/vtpmmgr/vtpmmgr.c
> +++ b/stubdom/vtpmmgr/vtpmmgr.c
> @@ -67,11 +67,21 @@ int hw_is_tpm2(void)
>      return (hardware_version.hw_version == TPM2_HARDWARE) ? 1 : 0;
>  }
>  
> +static int do_shutdown;
> +
> +void app_shutdown(unsigned int reason)
> +{
> +    printk("Shutdown requested: %d\n", reason);
> +    do_shutdown = 1;
> +
> +    shutdown_tpmback();
> +}
> +
>  void main_loop(void) {
>     tpmcmd_t* tpmcmd;
>     uint8_t respbuf[TCPA_MAX_BUFFER_LENGTH];
>  
> -   while(1) {
> +   while (!do_shutdown) {
>        /* Wait for requests from a vtpm */
>        vtpmloginfo(VTPM_LOG_VTPM, "Waiting for commands from vTPM's:\n");
>        if((tpmcmd = tpmback_req_any()) == NULL) {
>