[win-pv-devel] [PATCH 4/7] Maintain a global list of FDOs in XENBUS

[Paul Durrant <pdurrant@xxxxxxxxx>]

...similar to that in XENFILT.

Also add a missing mutex acquisition around FdoCreate() in XENFILT.

Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
 src/xenbus/driver.c  | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/xenbus/driver.h  | 18 ++++++++---
 src/xenbus/fdo.c     | 32 +++++++++++++++++--
 src/xenbus/fdo.h     |  5 +++
 src/xenfilt/driver.c |  6 ++++
 5 files changed, 141 insertions(+), 7 deletions(-)

diff --git a/src/xenbus/driver.c b/src/xenbus/driver.c
index 6135400..3409270 100644
--- a/src/xenbus/driver.c
+++ b/src/xenbus/driver.c
@@ -38,6 +38,7 @@
 #include "pdo.h"
 #include "driver.h"
 #include "names.h"
+#include "mutex.h"
 #include "dbg_print.h"
 #include "assert.h"
 #include "util.h"
@@ -49,6 +50,10 @@ typedef struct _XENBUS_DRIVER {
     PDRIVER_OBJECT      DriverObject;
     HANDLE              ParametersKey;
     HANDLE              StatusKey;
+
+    MUTEX               Mutex;
+    LIST_ENTRY          List;
+    ULONG               References;
 } XENBUS_DRIVER, *PXENBUS_DRIVER;
 
 static XENBUS_DRIVER    Driver;
@@ -149,6 +154,71 @@ DriverRequestReboot(
                                     1);
 }
 
+static FORCEINLINE VOID
+__DriverAcquireMutex(
+    VOID
+    )
+{
+    AcquireMutex(&Driver.Mutex);
+}
+
+VOID
+DriverAcquireMutex(
+    VOID
+    )
+{
+    __DriverAcquireMutex();
+}
+
+static FORCEINLINE VOID
+__DriverReleaseMutex(
+    VOID
+    )
+{
+    ReleaseMutex(&Driver.Mutex);
+}
+
+VOID
+DriverReleaseMutex(
+    VOID
+    )
+{
+    __DriverReleaseMutex();
+}
+
+VOID
+DriverAddFunctionDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    PDEVICE_OBJECT  DeviceObject;
+    PXENBUS_DX      Dx;
+
+    DeviceObject = FdoGetDeviceObject(Fdo);
+    Dx = (PXENBUS_DX)DeviceObject->DeviceExtension;
+    ASSERT3U(Dx->Type, ==, FUNCTION_DEVICE_OBJECT);
+
+    InsertTailList(&Driver.List, &Dx->ListEntry);
+    Driver.References++;
+}
+
+VOID
+DriverRemoveFunctionDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    PDEVICE_OBJECT  DeviceObject;
+    PXENBUS_DX      Dx;
+
+    DeviceObject = FdoGetDeviceObject(Fdo);
+    Dx = (PXENBUS_DX)DeviceObject->DeviceExtension;
+    ASSERT3U(Dx->Type, ==, FUNCTION_DEVICE_OBJECT);
+
+    RemoveEntryList(&Dx->ListEntry);
+    ASSERT3U(Driver.References, !=, 0);
+    --Driver.References;
+}
+
 DRIVER_UNLOAD       DriverUnload;
 
 VOID
@@ -166,6 +236,13 @@ DriverUnload(
     if (*InitSafeBootMode > 0)
         goto done;
 
+    ASSERT(IsListEmpty(&Driver.List));
+    ASSERT3U(Driver.References, ==, 1);
+    --Driver.References;
+
+    RtlZeroMemory(&Driver.List, sizeof (LIST_ENTRY));
+    RtlZeroMemory(&Driver.Mutex, sizeof (MUTEX));
+
     StatusKey = __DriverGetStatusKey();
     __DriverSetStatusKey(NULL);
 
@@ -210,16 +287,20 @@ DriverAddDevice(
 
     Trace("====>\n");
 
+    __DriverAcquireMutex();
+
     status = FdoCreate(DeviceObject);
     if (!NT_SUCCESS(status))
         goto fail1;
 
+    __DriverReleaseMutex();
+
     Trace("<====\n");
 
     return STATUS_SUCCESS;
 
 fail1:
-    Error("fail1 (%08x)\n", status);
+    __DriverReleaseMutex();
 
     return status;
 }
@@ -352,6 +433,10 @@ DriverEntry(
        DriverObject->MajorFunction[Index] = DriverDispatch;
     }
 
+    InitializeMutex(&Driver.Mutex);
+    InitializeListHead(&Driver.List);
+    Driver.References = 1;
+
 done:
     Trace("<====\n");
 
diff --git a/src/xenbus/driver.h b/src/xenbus/driver.h
index 0208f9c..78b1b25 100644
--- a/src/xenbus/driver.h
+++ b/src/xenbus/driver.h
@@ -48,14 +48,14 @@ DriverRequestReboot(
     );
 
 extern VOID
-DriverAddFilters(
+DriverAcquireMutex(
     VOID
-    );
+     );
 
 extern VOID
-DriverRemoveFilters(
+DriverReleaseMutex(
     VOID
-    );
+     );
 
 typedef struct _XENBUS_FDO      XENBUS_FDO, *PXENBUS_FDO;
 typedef struct _XENBUS_PDO      XENBUS_PDO, *PXENBUS_PDO;
@@ -65,6 +65,16 @@ typedef struct _XENBUS_PDO      XENBUS_PDO, *PXENBUS_PDO;
 
 #define MAX_DEVICE_ID_LEN   200
 
+extern VOID
+DriverAddFunctionDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    );
+
+extern VOID
+DriverRemoveFunctionDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    );
+
 #pragma warning(push)
 #pragma warning(disable:4201) // nonstandard extension used : nameless 
struct/union
 
diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
index 28ccb36..5d03f8c 100644
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -250,6 +250,24 @@ __FdoGetSystemPowerState(
 }
 
 static FORCEINLINE PDEVICE_OBJECT
+__FdoGetDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    PXENBUS_DX      Dx = Fdo->Dx;
+
+    return Dx->DeviceObject;
+}
+
+PDEVICE_OBJECT
+FdoGetDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    )
+{
+    return __FdoGetDeviceObject(Fdo);
+}
+
+static FORCEINLINE PDEVICE_OBJECT
 __FdoGetPhysicalDeviceObject(
     IN  PXENBUS_FDO Fdo
     )
@@ -1015,8 +1033,11 @@ FdoReleaseMutex(
 {
     __FdoReleaseMutex(Fdo);
 
-    if (Fdo->References == 0)
+    if (Fdo->References == 0) {
+        DriverAcquireMutex();
         FdoDestroy(Fdo);
+        DriverReleaseMutex();
+    }
 }
 
 static BOOLEAN
@@ -3513,8 +3534,11 @@ done:
     --Fdo->References;
     __FdoReleaseMutex(Fdo);
 
-    if (Fdo->References == 0)
+    if (Fdo->References == 0) {
+        DriverAcquireMutex();
         FdoDestroy(Fdo);
+        DriverReleaseMutex();
+    }
 
     return status;
 }
@@ -4923,6 +4947,8 @@ done:
     Dx->Fdo = Fdo;
     FunctionDeviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
 
+    DriverAddFunctionDeviceObject(Fdo);
+
     return STATUS_SUCCESS;
 
 fail19:
@@ -5053,6 +5079,8 @@ FdoDestroy(
     ASSERT3U(Fdo->References, ==, 0);
     ASSERT3U(__FdoGetDevicePnpState(Fdo), ==, Deleted);
 
+    DriverRemoveFunctionDeviceObject(Fdo);
+
     Fdo->NotDisableable = FALSE;
 
     Info("%p (%s)\n",
diff --git a/src/xenbus/fdo.h b/src/xenbus/fdo.h
index 96a2250..9e9b599 100644
--- a/src/xenbus/fdo.h
+++ b/src/xenbus/fdo.h
@@ -78,6 +78,11 @@ FdoReleaseMutex(
     );
 
 extern PDEVICE_OBJECT
+FdoGetDeviceObject(
+    IN  PXENBUS_FDO Fdo
+    );
+
+extern PDEVICE_OBJECT
 FdoGetPhysicalDeviceObject(
     IN  PXENBUS_FDO Fdo
     );
diff --git a/src/xenfilt/driver.c b/src/xenfilt/driver.c
index 77f719a..84766dd 100644
--- a/src/xenfilt/driver.c
+++ b/src/xenfilt/driver.c
@@ -572,6 +572,8 @@ DriverAddDevice(
                                   DeviceID,
                                   &Type);
     if (NT_SUCCESS(status)) {
+        __DriverAcquireMutex();
+
         status = FdoCreate(PhysicalDeviceObject,
                            DeviceID,
                            InstanceID,
@@ -580,12 +582,16 @@ DriverAddDevice(
         if (!NT_SUCCESS(status))
             goto fail3;
 
+        __DriverReleaseMutex();
+
         RegistryFreeSzValue(Type);
     }
 
     return STATUS_SUCCESS;
 
 fail3:
+        __DriverReleaseMutex();
+
 fail2:
 fail1:
     return status;
-- 
2.1.1


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