Re: [PATCH 3/5] ftgmac100: check RX and TX buffer alignment

[Cédric Le Goater]

On 1/7/20 9:27 AM, Philippe Mathieu-Daudé wrote:
> On 1/7/20 8:34 AM, Cédric Le Goater wrote:
>> These buffers should be aligned on 16 bytes.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>   hw/net/ftgmac100.c | 13 +++++++++++++
>>   1 file changed, 13 insertions(+)
>>
>> diff --git a/hw/net/ftgmac100.c b/hw/net/ftgmac100.c
>> index 86ac25894a89..051f7b7af2d6 100644
>> --- a/hw/net/ftgmac100.c
>> +++ b/hw/net/ftgmac100.c
>> @@ -198,6 +198,8 @@ typedef struct {
>>       uint32_t        des3;
>>   } FTGMAC100Desc;
>>   +#define FTGMAC100_DESC_ALIGNMENT 16
>> +
>>   /*
>>    * Specific RTL8211E MII Registers
>>    */
>> @@ -722,6 +724,12 @@ static void ftgmac100_write(void *opaque, hwaddr addr,
>>           s->itc = value;
>>           break;
>>       case FTGMAC100_RXR_BADR: /* Ring buffer address */
>> +        if (!QEMU_IS_ALIGNED(value, FTGMAC100_DESC_ALIGNMENT)) {
>> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad RX buffer alignment 0x%"
>> +                          HWADDR_PRIx "\n", __func__, value);
>> +            return;
> 
> What is the hardware behavior?

This is not documented :/

C.

> 
>> +        }
>> +
>>           s->rx_ring = value;
>>           s->rx_descriptor = s->rx_ring;
>>           break;
>> @@ -731,6 +739,11 @@ static void ftgmac100_write(void *opaque, hwaddr addr,
>>           break;
>>         case FTGMAC100_NPTXR_BADR: /* Transmit buffer address */
>> +        if (!QEMU_IS_ALIGNED(value, FTGMAC100_DESC_ALIGNMENT)) {
>> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad TX buffer alignment 0x%"
>> +                          HWADDR_PRIx "\n", __func__, value);
>> +            return;
>> +        }
>>           s->tx_ring = value;
>>           s->tx_descriptor = s->tx_ring;
>>           break;
>>
>