[libvirt] [PATCH v2 2/3] qemu: command: Enforce setting XDG variables for system QEMU
For session mode, only XDG_CACHE_HOME is set, because we want to remain
integrating with services in user session, but for system mode, this
would have become reading/writing to '/' which carries the obvious issue
with permissions (also, '/' is the wrong location in 99.9% cases anyway).
Signed-off-by: Erik Skultety <eskultet(a)redhat.com>
---
src/qemu/qemu_command.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3a2ec7f26c..23be0d8554 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -10658,6 +10658,22 @@ qemuBuildCommandLine(virQEMUDriverPtr driver,
virCommandAddEnvPassCommon(cmd);
+ /* For system QEMU we want to set both HOME and all the XDG variables to
+ * libDir/qemu otherwise apps QEMU links to might try to access the default
+ * home dir '/' which would always result in a permission issue.
+ *
+ * For session QEMU, we only want to set XDG_CACHE_HOME as cache data
+ * may be purged at any time and that should not affect any app. We
+ * do want VMs to integrate with services in user's session so we're
+ * not re-setting any other env variables
+ */
+ if (!driver->privileged) {
+ virCommandAddEnvFormat(cmd, "XDG_CACHE_HOME=%s/%s",
+ priv->libDir, ".cache");
+ } else {
+ virCommandAddEnvXDG(cmd, priv->libDir);
+ }
+
if (qemuBuildNameCommandLine(cmd, cfg, def, qemuCaps) < 0)
goto error;
--
2.20.1