Re: [PATCH v3 04/26] DAX: libvhost-user: Route slave message payload

[Stefan Hajnoczi]

On Wed, Apr 28, 2021 at 12:00:38PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" 
> 
> Route the uint64 payload from message replies on the slave back up
> through vu_process_message_reply and to the callers.
> 
> Signed-off-by: Dr. David Alan Gilbert 
> Reviewed-by: Stefan Hajnoczi 
> ---
>  subprojects/libvhost-user/libvhost-user.c | 14 +++---
>  1 file changed, 11 insertions(+), 3 deletions(-)

Reviewed-by: Stefan Hajnoczi 


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[PATCH v3 04/26] DAX: libvhost-user: Route slave message payload

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" 

Route the uint64 payload from message replies on the slave back up
through vu_process_message_reply and to the callers.

Signed-off-by: Dr. David Alan Gilbert 
Reviewed-by: Stefan Hajnoczi 
---
 subprojects/libvhost-user/libvhost-user.c | 14 +++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/subprojects/libvhost-user/libvhost-user.c 
b/subprojects/libvhost-user/libvhost-user.c
index fab7ca17ee..937f64480d 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -403,9 +403,11 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
  * Processes a reply on the slave channel.
  * Entered with slave_mutex held and releases it before exit.
  * Returns true on success.
+ * *payload is written on success
  */
 static bool
-vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
+vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg,
+ uint64_t *payload)
 {
 VhostUserMsg msg_reply;
 bool result = false;
@@ -425,7 +427,8 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg 
*vmsg)
 goto out;
 }
 
-result = msg_reply.payload.u64 == 0;
+*payload = msg_reply.payload.u64;
+result = true;
 
 out:
 pthread_mutex_unlock(&dev->slave_mutex);
@@ -1312,6 +1315,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, 
int fd,
 {
 int qidx = vq - dev->vq;
 int fd_num = 0;
+bool res;
+uint64_t payload = 0;
 VhostUserMsg vmsg = {
 .request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
 .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
@@ -1342,7 +1347,10 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, 
int fd,
 }
 
 /* Also unlocks the slave_mutex */
-return vu_process_message_reply(dev, &vmsg);
+res = vu_process_message_reply(dev, &vmsg, &payload);
+res = res && (payload == 0);
+
+return res;
 }
 
 static bool
-- 
2.31.1