Hi Prasad,
On 11/02/2017 06:37 AM, Paolo Bonzini wrote:
> On 02/11/2017 10:36, P J P wrote:
>> From: Prasad J Pandit <p...@fedoraproject.org>
>>
>> Port 92 configuration register holds an 8-bit value. Of 8-bits,
>> bits 0-1 are used and 2-7 are reserved. Restrict the supplied
>> value to 2 bits.
>
> This patch is not necessary. "Do nothing and just report back the value
> that was written" is an okay implementation of reserved bits.
>
> Paolo
>
>
>> Reported-by: Niu Guoxiang <niuguoxi...@huawei.com>
>> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org>
>> ---
>> hw/i386/pc.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> index 05985d4927..883384a599 100644
>> --- a/hw/i386/pc.c
>> +++ b/hw/i386/pc.c
>> @@ -515,6 +515,7 @@ static void port92_write(void *opaque, hwaddr addr,
>> uint64_t val,
>> Port92State *s = opaque;
>> int oldval = s->outport;
>>
>> + val &= 0x03;
>> DPRINTF("port92: write 0x%02" PRIx64 "\n", val);
You might want to report a guest error instead:
if (val & ~3) {
qemu_log_mask(LOG_GUEST_ERROR,
"port92: bits 2-7 are reserved "
"(wrote 0x%02" PRIx64 ")\n", val);
}
>> s->outport = val;
>> qemu_set_irq(s->a20_out, (val >> 1) & 1);
