On 06/12/2015 08:05 AM, Don Slutz wrote:
> Before:
> 
> commit c3c1bb99d1c11978d9ce94d1bdcf0705378c1459
> Author: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> Date:   Mon Mar 16 22:35:54 2015 -0700
> 
>     exec: Respect as_tranlsate_internal length clamp
> 
> it did not matter.  Only accept I/O that starts on 1st
> port.
> 
> Signed-off-by: Don Slutz <dslutz@verizon.com>
> CC: Don Slutz <don.slutz@gmail.com>
> ---
>  hw/misc/vmport.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/misc/vmport.c b/hw/misc/vmport.c
> index 7fcc00d..51b64bc 100644
> --- a/hw/misc/vmport.c
> +++ b/hw/misc/vmport.c
> @@ -69,6 +69,10 @@ static uint64_t vmport_ioport_read(void *opaque, hwaddr addr,
>      unsigned char command;
>      uint32_t eax;
>  
> +    /* Only support 1 address */
> +    if (addr) {
> +        return ~0U;
> +    }

Different answer on 32-bit platforms (there, ~0U is 0xffffffff, which
then 0-extends to uint64_t rather than your desired result of
0xffffffffffffffffULL).

Why can't you just 'return -1;'?

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org