[dpdk-dev] [PATCH v2 01/17] vhost: fix messages error checks

Maxime Coquelin maxime.coquelin at redhat.com
Wed Oct 3 09:50:42 CEST 2018



On 10/02/2018 04:15 PM, Ilya Maximets wrote:
> On 02.10.2018 12:36, Maxime Coquelin wrote:
>> Return of message handling has now changed to an enum that can
>> take non-negative value that is not zero in case a reply is
>> needed. But the code checking the variable afterwards has not
>> been updated, leading to success messages handling being
>> treated as errors.
>>
>> Fixes: 4e601952cae6 ("vhost: message handling implemented as a callback array")
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
>> ---
>>   lib/librte_vhost/vhost_user.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>> index 7ef3fb4a4..060b41893 100644
>> --- a/lib/librte_vhost/vhost_user.c
>> +++ b/lib/librte_vhost/vhost_user.c
>> @@ -1783,7 +1783,7 @@ vhost_user_msg_handler(int vid, int fd)
>>   	}
>>   
>>   skip_to_post_handle:
>> -	if (!ret && dev->extern_ops.post_msg_handle) {
>> +	if (ret != VH_RESULT_ERR && dev->extern_ops.post_msg_handle) {
>>   		uint32_t need_reply;
>>   
>>   		ret = (*dev->extern_ops.post_msg_handle)(
>> @@ -1800,10 +1800,10 @@ vhost_user_msg_handler(int vid, int fd)
>>   		vhost_user_unlock_all_queue_pairs(dev);
>>   
>>   	if (msg.flags & VHOST_USER_NEED_REPLY) {
> 
> Maybe we need to reply here only if we didn't reply
> already (not VH_RESULT_REPLY) ? Otherwise, we could
> reply twice (with payload and with return code).

Well, if the master sets this bit, it means it is waiting for
a "reply-ack", so not sending it would cause the master to wait
forever.

It is the master responsibility to not set this bit for requests
already expecting a non "reply-ack" reply (as you fixed it for
postcopy's set mem table case).

>> -		msg.payload.u64 = !!ret;
>> +		msg.payload.u64 = ret == VH_RESULT_ERR;
>>   		msg.size = sizeof(msg.payload.u64);
>>   		send_vhost_reply(fd, &msg);
>> -	} else if (ret) {
>> +	} else if (ret == VH_RESULT_ERR) {
>>   		RTE_LOG(ERR, VHOST_CONFIG,
>>   			"vhost message handling failed.\n");
>>   		return -1;
>>


More information about the dev mailing list