Re: [Qemu-devel] [PATCH v3 1/2] cdrom: Allow the TEST_UNIT_READY command after a cdrom change

[Ryan Harper <ryanh@us.ibm.com>]

* Amit Shah <amit.shah@redhat.com> [2011-04-07 03:53]:
> We restrict the commands that a guest can send us after a cdrom change
> event.  The current list includes REQUEST_SENSE and INQUIRY commands.
> Guests can also issue TEST_UNIT_READY to inquire for the status, so
> allow this command as well.
> 
> This also gets rid of one cause of the HSM violation errors in Linux
> guests.  Those errors came up because we had the UNIT_ATTENTION event
> pending and we replied with an error message to a command that should be
> allowed in such a condition.  The guest then did a soft reset to get to
> a sane state.
> 
> Signed-off-by: Amit Shah <amit.shah@redhat.com>
> ---
>  hw/ide/core.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index 007a4ee..d55d804 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -1105,10 +1105,11 @@ static void ide_atapi_cmd(IDEState *s)
>      /* If there's a UNIT_ATTENTION condition pending, only
>         REQUEST_SENSE and INQUIRY commands are allowed to complete. */

Wasn't this comment going to get updated to be more generic (ie more
than just the 3 commands below may be needed?)

>      if (s->sense_key == SENSE_UNIT_ATTENTION &&
> -	s->io_buffer[0] != GPCMD_REQUEST_SENSE &&
> -	s->io_buffer[0] != GPCMD_INQUIRY) {
> -	ide_atapi_cmd_check_status(s);
> -	return;
> +        s->io_buffer[0] != GPCMD_REQUEST_SENSE &&
> +        s->io_buffer[0] != GPCMD_INQUIRY &&
> +        s->io_buffer[0] != GPCMD_TEST_UNIT_READY) {
> +        ide_atapi_cmd_check_status(s);
> +        return;
>      }
>      switch(s->io_buffer[0]) {
>      case GPCMD_TEST_UNIT_READY:
> -- 
> 1.7.4
> 

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com