[RFC PATCH 5/5] Add UNPLUG v3

[Owen Smith <owen.smith@xxxxxxxxx>]

Adds UnplugBootEmulated, which reports if the SystemStartOptions indicates
the boot disk should remain emulated (i.e. not unplugged)
Adds UnplugReboot, which can be used to issue the reboot request, so that
child drivers can abide by Driver Verifier's registry isolation rules

Signed-off-by: Owen Smith <owen.smith@xxxxxxxxx>
---
 include/revision.h         |  3 +-
 include/unplug_interface.h | 40 +++++++++++++++++-
 src/xenbus/unplug.c        | 86 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+), 3 deletions(-)

diff --git a/include/revision.h b/include/revision.h
index 9577fdb..4c5607a 100644
--- a/include/revision.h
+++ b/include/revision.h
@@ -58,6 +58,7 @@
     DEFINE_REVISION(0x09000007,  1,  3,  8,  1,  2,  1,  2,  4,  1,  1,  2), \
     DEFINE_REVISION(0x09000008,  1,  3,  9,  1,  2,  1,  2,  4,  1,  1,  2), \
     DEFINE_REVISION(0x09000009,  1,  4,  9,  1,  2,  1,  2,  4,  1,  1,  2), \
-    DEFINE_REVISION(0x0900000A,  1,  4,  9,  1,  2,  1,  2,  4,  2,  1,  2)
+    DEFINE_REVISION(0x0900000A,  1,  4,  9,  1,  2,  1,  2,  4,  2,  1,  2), \
+    DEFINE_REVISION(0x0900000B,  1,  4,  9,  1,  2,  1,  2,  4,  3,  1,  2)
 
 #endif  // _REVISION_H
diff --git a/include/unplug_interface.h b/include/unplug_interface.h
index dbdc76d..dad3afc 100644
--- a/include/unplug_interface.h
+++ b/include/unplug_interface.h
@@ -99,6 +99,28 @@ typedef BOOLEAN
     IN  XENBUS_UNPLUG_DEVICE_TYPE   Type
     );
 
+/*! \typedef XENBUS_UNPLUG_BOOT_EMULATED
+    \brief Should the boot disk be emulated
+
+    \param Interface The interface header
+*/
+typedef BOOLEAN
+(*XENBUS_UNPLUG_BOOT_EMULATED)(
+    IN  PINTERFACE                  Interface
+    );
+
+/*! \typedef XENBUS_UNPLUG_REBOOT
+    \brief Request a reboot to complete setup
+
+    \param Interface The interface header
+    \param Module The module name requesting a reboot
+*/
+typedef VOID
+(*XENBUS_UNPLUG_REBOOT)(
+    IN  PINTERFACE                  Interface,
+    IN  PCHAR                       Module
+    );
+
 // {73db6517-3d06-4937-989f-199b7501e229}
 DEFINE_GUID(GUID_XENBUS_UNPLUG_INTERFACE,
 0x73db6517, 0x3d06, 0x4937, 0x98, 0x9f, 0x19, 0x9b, 0x75, 0x01, 0xe2, 0x29);
@@ -126,7 +148,21 @@ struct _XENBUS_UNPLUG_INTERFACE_V2 {
     XENBUS_UNPLUG_IS_REQUESTED  UnplugIsRequested;
 };
 
-typedef struct _XENBUS_UNPLUG_INTERFACE_V2 XENBUS_UNPLUG_INTERFACE, 
*PXENBUS_UNPLUG_INTERFACE;
+/*! \struct _XENBUS_UNPLUG_INTERFACE_V3
+    \brief UNPLUG interface version 3
+    \ingroup interfaces
+*/
+struct _XENBUS_UNPLUG_INTERFACE_V3 {
+    INTERFACE                   Interface;
+    XENBUS_UNPLUG_ACQUIRE       UnplugAcquire;
+    XENBUS_UNPLUG_RELEASE       UnplugRelease;
+    XENBUS_UNPLUG_REQUEST       UnplugRequest;
+    XENBUS_UNPLUG_IS_REQUESTED  UnplugIsRequested;
+    XENBUS_UNPLUG_BOOT_EMULATED UnplugBootEmulated;
+    XENBUS_UNPLUG_REBOOT        UnplugReboot;
+};
+
+typedef struct _XENBUS_UNPLUG_INTERFACE_V3 XENBUS_UNPLUG_INTERFACE, 
*PXENBUS_UNPLUG_INTERFACE;
 
 /*! \def XENBUS_UNPLUG
     \brief Macro at assist in method invocation
@@ -137,6 +173,6 @@ typedef struct _XENBUS_UNPLUG_INTERFACE_V2 
XENBUS_UNPLUG_INTERFACE, *PXENBUS_UNP
 #endif  // _WINDLL
 
 #define XENBUS_UNPLUG_INTERFACE_VERSION_MIN  1
-#define XENBUS_UNPLUG_INTERFACE_VERSION_MAX  2
+#define XENBUS_UNPLUG_INTERFACE_VERSION_MAX  3
 
 #endif  // _XENBUS_UNPLUG_INTERFACE_H
diff --git a/src/xenbus/unplug.c b/src/xenbus/unplug.c
index 7c5ffc4..a3f9b71 100644
--- a/src/xenbus/unplug.c
+++ b/src/xenbus/unplug.c
@@ -42,6 +42,7 @@
 #include "dbg_print.h"
 #include "assert.h"
 #include "util.h"
+#include "registry.h"
 
 struct _XENBUS_UNPLUG_CONTEXT {
     KSPIN_LOCK  Lock;
@@ -144,6 +145,64 @@ UnplugIsRequested(
     return Requested;
 }
 
+__drv_requiresIRQL(PASSIVE_LEVEL)
+static BOOLEAN
+UnplugBootEmulated(
+    IN  PINTERFACE                  Interface
+    )
+{
+    PXENBUS_UNPLUG_CONTEXT          Context = Interface->Context;
+    CHAR                            KeyName[] = "XEN:BOOT_EMULATED=";
+    PANSI_STRING                    Option;
+    PCHAR                           Value;
+    NTSTATUS                        status;
+    BOOLEAN                         BootEmulated;
+
+    ASSERT3U(KeGetCurrentIrql(), ==, PASSIVE_LEVEL);
+
+    AcquireMutex(&Context->Mutex);
+
+    BootEmulated = FALSE;
+
+    status = ConfigQuerySystemStartOption(KeyName, &Option);
+    if (!NT_SUCCESS(status))
+        goto done;
+
+    Value = Option->Buffer + sizeof (KeyName) - 1;
+
+    if (strcmp(Value, "TRUE") == 0)
+        BootEmulated = TRUE;
+    else if (strcmp(Value, "FALSE") != 0)
+        Warning("UNRECOGNIZED VALUE OF %s: %s\n", KeyName, Value);
+
+    RegistryFreeSzValue(Option);
+
+done:
+    ReleaseMutex(&Context->Mutex);
+
+    return BootEmulated;
+}
+
+__drv_requiresIRQL(PASSIVE_LEVEL)
+static VOID
+UnplugReboot(
+    IN  PINTERFACE                  Interface,
+    IN  PCHAR                       Module
+    )
+{
+    PXENBUS_UNPLUG_CONTEXT          Context = Interface->Context;
+
+    ASSERT3U(KeGetCurrentIrql(), ==, PASSIVE_LEVEL);
+
+    AcquireMutex(&Context->Mutex);
+
+    ConfigRequestReboot(DriverGetParametersKey(), Module);
+
+    ReleaseMutex(&Context->Mutex);
+
+    return;
+}
+
 static NTSTATUS
 UnplugAcquire(
     IN  PINTERFACE          Interface
@@ -199,6 +258,16 @@ static struct _XENBUS_UNPLUG_INTERFACE_V2 
UnplugInterfaceVersion2 = {
     UnplugIsRequested
 };
 
+static struct _XENBUS_UNPLUG_INTERFACE_V3 UnplugInterfaceVersion3 = {
+    { sizeof (struct _XENBUS_UNPLUG_INTERFACE_V3), 3, NULL, NULL, NULL },
+    UnplugAcquire,
+    UnplugRelease,
+    UnplugRequest,
+    UnplugIsRequested,
+    UnplugBootEmulated,
+    UnplugReboot
+};
+
 NTSTATUS
 UnplugInitialize(
     IN  PXENBUS_FDO             Fdo,
@@ -277,6 +346,23 @@ UnplugGetInterface(
         status = STATUS_SUCCESS;
         break;
     }
+    case 3: {
+        struct _XENBUS_UNPLUG_INTERFACE_V3   *UnplugInterface;
+
+        UnplugInterface = (struct _XENBUS_UNPLUG_INTERFACE_V3 *)Interface;
+
+        status = STATUS_BUFFER_OVERFLOW;
+        if (Size < sizeof (struct _XENBUS_UNPLUG_INTERFACE_V3))
+            break;
+
+        *UnplugInterface = UnplugInterfaceVersion3;
+
+        ASSERT3U(Interface->Version, ==, Version);
+        Interface->Context = Context;
+
+        status = STATUS_SUCCESS;
+        break;
+    }
     default:
         status = STATUS_NOT_SUPPORTED;
         break;
-- 
2.44.0.windows.1