[v3] net/iavf: fix virtual channel return value error
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Commit Message
In iavf_handle_virtchnl_msg(), it is not appropriate for _clear_cmd()
to be used as a notification to forground thread. So introduce
_notify_cmd() to fix this error. In addition, since _notify_cmd()
contains rte_wmb(), rte_compiler_barrier() is not necessary.
Sending msg from VF to PF is mainly by calling iavf_execute_vf_cmd(),
the whole virtchnl msg process is like,
iavf_execute_vf_cmd() will call iavf_aq_send_msg_to_pf() to send
msg and then polling the cmd done flag as "if (vf->pend_cmd ==
VIRTCHNL_OP_UNKNOWN)"
When reply msg is returned by pf, iavf_handle_virtchnl_msg() in
isr will read msg return value by "vf->cmd_retval = msg_ret" and
immediately set the cmd done flag by calling _clear_cmd() to
notify the iavf_execute_vf_cmd().
iavf_execute_vf_cmd() find the cmd done flag is set and then
check whether command return value vf->cmd_retval is success or
not.
However _clear_cmd() also resets the vf->cmd_retval to success,
overwriting the actual return value which is used for diagnosis.
So iavf_execute_vf_cmd() will always find vf->cmd_retval is
success and then return success.
Fixes: 22b123a36d07 ("net/avf: initialize PMD")
Cc: stable@dpdk.org
Signed-off-by: Yahui Cao <yahui.cao@intel.com>
---
drivers/net/iavf/iavf.h | 11 +++++++++++
drivers/net/iavf/iavf_vchnl.c | 9 +++------
2 files changed, 14 insertions(+), 6 deletions(-)
Comments
> -----Original Message-----
> From: Cao, Yahui <yahui.cao@intel.com>
> Sent: Tuesday, December 24, 2019 12:13 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org; Zhang, Qi Z <qi.z.zhang@intel.com>; Cao,
> Yahui <yahui.cao@intel.com>; Ye, Xiaolong <xiaolong.ye@intel.com>; Su,
> Simei <simei.su@intel.com>
> Subject: [PATCH v3] net/iavf: fix virtual channel return value error
>
> In iavf_handle_virtchnl_msg(), it is not appropriate for _clear_cmd() to be used
> as a notification to forground thread. So introduce
> _notify_cmd() to fix this error. In addition, since _notify_cmd() contains
> rte_wmb(), rte_compiler_barrier() is not necessary.
>
> Sending msg from VF to PF is mainly by calling iavf_execute_vf_cmd(), the
> whole virtchnl msg process is like,
>
> iavf_execute_vf_cmd() will call iavf_aq_send_msg_to_pf() to send msg and
> then polling the cmd done flag as "if (vf->pend_cmd ==
> VIRTCHNL_OP_UNKNOWN)"
>
> When reply msg is returned by pf, iavf_handle_virtchnl_msg() in isr will read
> msg return value by "vf->cmd_retval = msg_ret" and immediately set the cmd
> done flag by calling _clear_cmd() to notify the iavf_execute_vf_cmd().
>
> iavf_execute_vf_cmd() find the cmd done flag is set and then check whether
> command return value vf->cmd_retval is success or not.
>
> However _clear_cmd() also resets the vf->cmd_retval to success, overwriting
> the actual return value which is used for diagnosis.
> So iavf_execute_vf_cmd() will always find vf->cmd_retval is success and then
> return success.
>
> Fixes: 22b123a36d07 ("net/avf: initialize PMD")
> Cc: stable@dpdk.org
>
> Signed-off-by: Yahui Cao <yahui.cao@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>
On 12/24, Zhang, Qi Z wrote:
>
>
>> -----Original Message-----
>> From: Cao, Yahui <yahui.cao@intel.com>
>> Sent: Tuesday, December 24, 2019 12:13 PM
>> To: Wu, Jingjing <jingjing.wu@intel.com>; Lu, Wenzhuo
>> <wenzhuo.lu@intel.com>
>> Cc: dev@dpdk.org; stable@dpdk.org; Zhang, Qi Z <qi.z.zhang@intel.com>; Cao,
>> Yahui <yahui.cao@intel.com>; Ye, Xiaolong <xiaolong.ye@intel.com>; Su,
>> Simei <simei.su@intel.com>
>> Subject: [PATCH v3] net/iavf: fix virtual channel return value error
>>
>> In iavf_handle_virtchnl_msg(), it is not appropriate for _clear_cmd() to be used
>> as a notification to forground thread. So introduce
>> _notify_cmd() to fix this error. In addition, since _notify_cmd() contains
>> rte_wmb(), rte_compiler_barrier() is not necessary.
>>
>> Sending msg from VF to PF is mainly by calling iavf_execute_vf_cmd(), the
>> whole virtchnl msg process is like,
>>
>> iavf_execute_vf_cmd() will call iavf_aq_send_msg_to_pf() to send msg and
>> then polling the cmd done flag as "if (vf->pend_cmd ==
>> VIRTCHNL_OP_UNKNOWN)"
>>
>> When reply msg is returned by pf, iavf_handle_virtchnl_msg() in isr will read
>> msg return value by "vf->cmd_retval = msg_ret" and immediately set the cmd
>> done flag by calling _clear_cmd() to notify the iavf_execute_vf_cmd().
>>
>> iavf_execute_vf_cmd() find the cmd done flag is set and then check whether
>> command return value vf->cmd_retval is success or not.
>>
>> However _clear_cmd() also resets the vf->cmd_retval to success, overwriting
>> the actual return value which is used for diagnosis.
>> So iavf_execute_vf_cmd() will always find vf->cmd_retval is success and then
>> return success.
>>
>> Fixes: 22b123a36d07 ("net/avf: initialize PMD")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Yahui Cao <yahui.cao@intel.com>
>
>Acked-by: Qi Zhang <qi.z.zhang@intel.com>
>
Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>
Applied to dpdk-next-net-intel, Thanks.
@@ -173,6 +173,17 @@ struct iavf_cmd_info {
uint32_t out_size; /* buffer size for response */
};
+/* notify current command done. Only call in case execute
+ * _atomic_set_cmd successfully.
+ */
+static inline void
+_notify_cmd(struct iavf_info *vf, uint32_t msg_ret)
+{
+ vf->cmd_retval = msg_ret;
+ rte_wmb();
+ vf->pend_cmd = VIRTCHNL_OP_UNKNOWN;
+}
+
/* clear current command. Only call in case execute
* _atomic_set_cmd successfully.
*/
@@ -210,12 +210,9 @@ iavf_handle_virtchnl_msg(struct rte_eth_dev *dev)
info.msg_len);
} else {
/* read message and it's expected one */
- if (msg_opc == vf->pend_cmd) {
- vf->cmd_retval = msg_ret;
- /* prevent compiler reordering */
- rte_compiler_barrier();
- _clear_cmd(vf);
- } else
+ if (msg_opc == vf->pend_cmd)
+ _notify_cmd(vf, msg_ret);
+ else
PMD_DRV_LOG(ERR, "command mismatch,"
"expect %u, get %u",
vf->pend_cmd, msg_opc);