Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2020-03-24-tag0' into staging

qemu-ga patch queue for hard-freeze

* fix undefined C behavior with guest-file-* interfaces
* fix w32 installer issues
* fix crash for large file reads via guest-file-read on windows
* add missing man page documentation for virtio-vsock

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* remotes/mdroth/tags/qga-pull-2020-03-24-tag0:
  qemu-ga: document vsock-listen in the man page
  qga: Fix undefined C behavior
  qga-win: prevent crash when executing guest-file-read with large count
  qga-win: Handle VSS_E_PROVIDER_ALREADY_REGISTERED error
  qga: Installer: Wait for installation to finish

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 32 insertions, 7 deletions

diff --git a/docs/interop/qemu-ga.rst b/docs/interop/qemu-ga.rst
index 1313a4ae1c..3063357bb5 100644
--- a/docs/interop/qemu-ga.rst
+++ b/docs/interop/qemu-ga.rst
@@ -36,13 +36,14 @@ Options
 .. option:: -m, --method=METHOD
 
   Transport method: one of ``unix-listen``, ``virtio-serial``, or
-  ``isa-serial`` (``virtio-serial`` is the default).
+  ``isa-serial``, or ``vsock-listen`` (``virtio-serial`` is the default).
 
 .. option:: -p, --path=PATH
 
   Device/socket path (the default for virtio-serial is
   ``/dev/virtio-ports/org.qemu.guest_agent.0``,
-  the default for isa-serial is ``/dev/ttyS0``)
+  the default for isa-serial is ``/dev/ttyS0``). Socket addresses for
+  vsock-listen are written as ``<cid>:<port>``.
 
 .. option:: -l, --logfile=PATH
 
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 9c744d6405..b49920e201 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -343,7 +343,13 @@ GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
     }
 
     fh = gfh->fh;
-    buf = g_malloc0(count+1);
+    buf = g_try_malloc0(count + 1);
+    if (!buf) {
+        error_setg(errp,
+                   "failed to allocate sufficient memory "
+                   "to complete the requested service");
+        return NULL;
+    }
     is_ok = ReadFile(fh, buf, count, &read_count, NULL);
     if (!is_ok) {
         error_setg_win32(errp, GetLastError(), "failed to read file");
diff --git a/qga/commands.c b/qga/commands.c
index f8852beb9c..4471a9f08d 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -482,10 +482,15 @@ done:
  * the guest's SEEK_ constants.  */
 int ga_parse_whence(GuestFileWhence *whence, Error **errp)
 {
-    /* Exploit the fact that we picked values to match QGA_SEEK_*. */
+    /*
+     * Exploit the fact that we picked values to match QGA_SEEK_*;
+     * however, we have to use a temporary variable since the union
+     * members may have different size.
+     */
     if (whence->type == QTYPE_QSTRING) {
+        int value = whence->u.name;
         whence->type = QTYPE_QNUM;
-        whence->u.value = whence->u.name;
+        whence->u.value = value;
     }
     switch (whence->u.value) {
     case QGA_SEEK_SET:
diff --git a/qga/installer/qemu-ga.wxs b/qga/installer/qemu-ga.wxs
index 64bf90bd85..f6781752e6 100644
--- a/qga/installer/qemu-ga.wxs
+++ b/qga/installer/qemu-ga.wxs
@@ -81,7 +81,7 @@
               Arguments="-d --retry-path"
               >
             </ServiceInstall>
-            <ServiceControl Id="StartService" Start="install" Stop="both" Remove="uninstall" Name="QEMU-GA" Wait="no" />
+            <ServiceControl Id="StartService" Start="install" Stop="both" Remove="uninstall" Name="QEMU-GA" Wait="yes" />
           </Component>
           <?ifdef var.InstallVss?>
           <Component Id="qga_vss_dll" Guid="{CB19C453-FABB-4BB1-ABAB-6B74F687BFBB}">
diff --git a/qga/main.c b/qga/main.c
index 8ee2736f8e..f0e454f28d 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -234,7 +234,9 @@ QEMU_COPYRIGHT "\n"
 "  -p, --path        device/socket path (the default for virtio-serial is:\n"
 "                    %s,\n"
 "                    the default for isa-serial is:\n"
-"                    %s)\n"
+"                    %s).\n"
+"                    Socket addresses for vsock-listen are written as\n"
+"                    <cid>:<port>.\n"
 "  -l, --logfile     set logfile path, logs to stderr by default\n"
 "  -f, --pidfile     specify pidfile (default is %s)\n"
 #ifdef CONFIG_FSFREEZE
diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
index 6713e58670..a456841360 100644
--- a/qga/vss-win32/install.cpp
+++ b/qga/vss-win32/install.cpp
@@ -443,6 +443,17 @@ STDAPI DllRegisterServer(void)
                                      VSS_PROV_SOFTWARE,
                                      const_cast<WCHAR*>(QGA_PROVIDER_VERSION),
                                      g_gProviderVersion);
+    if (hr == (long int) VSS_E_PROVIDER_ALREADY_REGISTERED) {
+        DllUnregisterServer();
+        hr = pVssAdmin->RegisterProvider(g_gProviderId, CLSID_QGAVSSProvider,
+                                         const_cast<WCHAR * >
+                                         (QGA_PROVIDER_LNAME),
+                                         VSS_PROV_SOFTWARE,
+                                         const_cast<WCHAR * >
+                                         (QGA_PROVIDER_VERSION),
+                                         g_gProviderVersion);
+    }
+
     if (FAILED(hr)) {
         errmsg_dialog(hr, "RegisterProvider failed");
     }