On 10/03/2018 09:57 AM, Ilya Maximets wrote:
On 03.10.2018 10:50, Maxime Coquelin wrote:
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.coque...@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).
vhost-user docs in QEMU says:
"
For the message types that already solicit a reply from the client, the
presence of VHOST_USER_PROTOCOL_F_REPLY_ACK or need_reply bit being set brings
no behavioural change.
"
i.e. even if QEMU sets the need_reply flag, vhost should not reply twice.
Am I missing something?
Oh, right. Thanks for pointing it out.
So coming back to the DPDK implementation, I just had a look again, and
it seems that we don't send a reply twice, as send_vhost_reply takes
care of clearing the VHOST_USER_NEED_REPLY flag.
Do you confirm my understanding is correct?
- 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;
