[PATCH 2/2] qemu: tpm: Remove TPM state after successful migration

[Stefan Berger]

This patch 'fixes' the behavior of the persistent_state TPM domain XML
attribute that intends to preserve the state of the TPM but should not
keep the state around on all the hosts a VM has been migrated to. It
removes the TPM state directory structure from the source host upon
successful migration when non-shared storage is used. Similarly, it
removes it from the destination host upon migration failure when
non-shared storage is used.

Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
---
 src/qemu/qemu_migration.c | 14 +++++++++++---
 src/qemu/qemu_tpm.h       | 12 ++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 7f69991e2b..355a2cb5c7 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -38,6 +38,7 @@
 #include "qemu_security.h"
 #include "qemu_slirp.h"
 #include "qemu_block.h"
+#include "qemu_tpm.h"
 
 #include "domain_audit.h"
 #include "virlog.h"
@@ -4006,6 +4007,7 @@ qemuMigrationSrcConfirm(virQEMUDriver *driver,
     qemuMigrationJobPhase phase;
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
     qemuDomainObjPrivate *priv = vm->privateData;
+    virDomainUndefineFlagsValues undefFlags = 0;
     int ret = -1;
 
     VIR_DEBUG("vm=%p, flags=0x%x, cancelled=%d", vm, flags, cancelled);
@@ -4054,7 +4056,9 @@ qemuMigrationSrcConfirm(virQEMUDriver *driver,
             virDomainDeleteConfig(cfg->configDir, cfg->autostartDir, vm);
             vm->persistent = 0;
         }
-        qemuDomainRemoveInactive(driver, vm, 0);
+        if (!qemuTPMCheckKeepTPMStateMigrationSrcSuccess(vm))
+            undefFlags |= VIR_DOMAIN_UNDEFINE_TPM;
+        qemuDomainRemoveInactive(driver, vm, undefFlags);
     }
 
  cleanup:
@@ -6590,6 +6594,7 @@ qemuMigrationDstFinishActive(virQEMUDriver *driver,
     virObjectEvent *event;
     bool inPostCopy = false;
     bool doKill = priv->job.phase != QEMU_MIGRATION_PHASE_FINISH_RESUME;
+    virDomainUndefineFlagsValues undefFlags = 0;
     int rc;
 
     VIR_DEBUG("vm=%p, flags=0x%lx, retcode=%d",
@@ -6666,8 +6671,11 @@ qemuMigrationDstFinishActive(virQEMUDriver *driver,
                                  jobPriv->migParams, priv->job.apiFlags);
     }
 
-    if (!virDomainObjIsActive(vm))
-        qemuDomainRemoveInactive(driver, vm, 0);
+    if (!virDomainObjIsActive(vm)) {
+        if (!qemuTPMCheckKeepTPMStateMigrationDstFailure(vm))
+            undefFlags |= VIR_DOMAIN_UNDEFINE_TPM;
+        qemuDomainRemoveInactive(driver, vm, undefFlags);
+    }
 
     virErrorRestore(&orig_err);
     return NULL;
diff --git a/src/qemu/qemu_tpm.h b/src/qemu/qemu_tpm.h
index f068f3ca5a..c5d8774f07 100644
--- a/src/qemu/qemu_tpm.h
+++ b/src/qemu/qemu_tpm.h
@@ -56,3 +56,15 @@ int qemuExtTPMSetupCgroup(virQEMUDriver *driver,
                           virCgroup *cgroup)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
     G_GNUC_WARN_UNUSED_RESULT;
+
+static inline bool
+qemuTPMCheckKeepTPMStateMigrationSrcSuccess(virDomainObj *vm G_GNUC_UNUSED)
+{
+    return false;
+}
+
+static inline bool
+qemuTPMCheckKeepTPMStateMigrationDstFailure(virDomainObj *vm G_GNUC_UNUSED)
+{
+    return false;
+}
-- 
2.37.1