From: Martin Harvey <Martin.Harvey@citrix.com>
Date: Wed, 28 Jul 2021 14:02:45 +0000 (+0100)
Subject: Log waits for backend state changes.
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=c8ba37477306605c76a076ad6ee29baf87de20dd;p=pvdrivers%2Fwin%2Fxenvif.git

Log waits for backend state changes.

In addition to preceding changes to ring disconnects, and
associated logging, we also add some logging to check
whether state change notifications are being sent in a timely
manner between frontend and backend. Also a great assistance
to customer debugging.

Signed-off-by: Martin Harvey <martin.harvey@citrix.com>
---

diff --git a/src/xenvif/frontend.c b/src/xenvif/frontend.c
index 5940e16..72f448d 100644
--- a/src/xenvif/frontend.c
+++ b/src/xenvif/frontend.c
@@ -1346,6 +1346,7 @@ FrontendWaitForBackendXenbusStateChange(
     LARGE_INTEGER               Timeout;
     XenbusState                 Old = *State;
     NTSTATUS                    status;
+    const ULONGLONG             TotalTimeout = 120000;
 
     Trace("%s: ====> %s\n",
           __FrontendGetBackendPath(Frontend),
@@ -1369,7 +1370,7 @@ FrontendWaitForBackendXenbusStateChange(
 
     Timeout.QuadPart = 0;
 
-    while (*State == Old && TimeDelta < 120000) {
+    while (*State == Old && TimeDelta < TotalTimeout) {
         PCHAR           Buffer;
         LARGE_INTEGER   Now;
 
@@ -1417,6 +1418,9 @@ FrontendWaitForBackendXenbusStateChange(
         TimeDelta = (Now.QuadPart - Start.QuadPart) / 10000ull;
     }
 
+    if (TimeDelta >= TotalTimeout)
+        Error("%s timed out waiting for backend state change\n", __FrontendGetBackendPath(Frontend));
+
     if (Watch != NULL)
         (VOID) XENBUS_STORE(WatchRemove,
                             &Frontend->StoreInterface,