From: Paul Durrant <paul.durrant@citrix.com>
Date: Wed, 1 Apr 2015 07:53:54 +0000 (+0100)
Subject: Make sure SYNC per-processor structures are zeroed after resume
X-Git-Tag: 8.1.0-rc1~33
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=51812817397bcd83c92ab318e845b08040f31b50;p=pvdrivers%2Fwin%2Fxenbus.git

Make sure SYNC per-processor structures are zeroed after resume

Since the per-processor data in the SYNC code was split out from the
main context structure, the code that zeroes that structure on resume
no longer clears the per-processor Exit flag. This means that a multi-
vcpu VM can only be suspended once; subsequent attempts will fail.
This patch fixes the problem by zeroing the full page containing the SYNC
context structure and any per-processor data.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---

diff --git a/src/xenbus/sync.c b/src/xenbus/sync.c
index 835b46b..661aabe 100644
--- a/src/xenbus/sync.c
+++ b/src/xenbus/sync.c
@@ -255,7 +255,7 @@ SyncCapture(
 
     Trace("====> (%u:%u)\n", Group, Number);
 
-    ASSERT(IsZeroMemory(Context, sizeof (SYNC_CONTEXT)));
+    ASSERT(IsZeroMemory(Context, PAGE_SIZE));
 
     Context->Sequence++;
     Context->CompletionCount = 0;
@@ -427,7 +427,7 @@ SyncRelease(
         KeMemoryBarrier();
     }
 
-    RtlZeroMemory(Context, sizeof (SYNC_CONTEXT));
+    RtlZeroMemory(Context, PAGE_SIZE);
 
     Index = KeGetCurrentProcessorNumberEx(NULL);
     __SyncRelease(Index);