[libvirt] [PATCH] qemu: fix EFI nvram removal on domain undefine

[Pavel Mores]

When undefining a UEFI domain its nvram file has to be properly handled as
well.  It's mandatory to use one of --nvram and --keep-nvram options when
'virsh undefine <domain>' is issued for a UEFI domain.  To fix the bug as
reported, virsh should return an error message if neither option is used
and the nvram file should be removed when --nvram is given.

The cause of the problem is that when qemuDomainUndefineFlags() is invoked
on an inactive domain the path to its nvram file is empty.  This commit
aims to fix this by formatting and filling in the path in time for the
nvram removal code to run properly.

https://bugzilla.redhat.com/show_bug.cgi?id=1751596

Signed-off-by: Pavel Mores <pmores at redhat.com>
---
 src/qemu/qemu_domain.c | 12 +++++++++---
 src/qemu/qemu_domain.h |  4 ++++
 src/qemu/qemu_driver.c | 20 +++++++++++++++-----
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 35067c851f..1a0367cc27 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -15441,16 +15441,22 @@ qemuDomainDiskIsMissingLocalOptional(virDomainDiskDefPtr disk)
 }
 
 
+int
+qemuDomainNVRAMPathFormat(virQEMUDriverConfigPtr cfg,
+                            virDomainDefPtr def, char **path)
+{
+    return virAsprintf(path, "%s/%s_VARS.fd", cfg->nvramDir, def->name);
+}
+
 int
 qemuDomainNVRAMPathGenerate(virQEMUDriverConfigPtr cfg,
                             virDomainDefPtr def)
 {
     if (def->os.loader &&
         def->os.loader->type == VIR_DOMAIN_LOADER_TYPE_PFLASH &&
-        def->os.loader->readonly == VIR_TRISTATE_SWITCH_ON &&
+        def->os.loader->readonly == VIR_TRISTATE_BOOL_YES &&
         !def->os.loader->nvram) {
-        return virAsprintf(&def->os.loader->nvram, "%s/%s_VARS.fd",
-                           cfg->nvramDir, def->name);
+        return qemuDomainNVRAMPathFormat(cfg, def, &def->os.loader->nvram);
     }
 
     return 0;
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 01a54d4265..07725c7cc4 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -1207,6 +1207,10 @@ qemuDomainIsUsingNoShutdown(qemuDomainObjPrivatePtr priv);
 bool
 qemuDomainDiskIsMissingLocalOptional(virDomainDiskDefPtr disk);
 
+int
+qemuDomainNVRAMPathFormat(virQEMUDriverConfigPtr cfg,
+                            virDomainDefPtr def, char **path);
+
 int
 qemuDomainNVRAMPathGenerate(virQEMUDriverConfigPtr cfg,
                             virDomainDefPtr def);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index bc0ede2fb0..dcaadbdb52 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -7828,6 +7828,8 @@ qemuDomainUndefineFlags(virDomainPtr dom,
     int nsnapshots;
     int ncheckpoints;
     virQEMUDriverConfigPtr cfg = NULL;
+    char *nvram_path = NULL;
+    bool need_deallocate_nvram_path = false;
 
     virCheckFlags(VIR_DOMAIN_UNDEFINE_MANAGED_SAVE |
                   VIR_DOMAIN_UNDEFINE_SNAPSHOTS_METADATA |
@@ -7905,14 +7907,20 @@ qemuDomainUndefineFlags(virDomainPtr dom,
         }
     }
 
-    if (vm->def->os.loader &&
-        vm->def->os.loader->nvram &&
-        virFileExists(vm->def->os.loader->nvram)) {
+    if (vm->def->os.firmware == VIR_DOMAIN_OS_DEF_FIRMWARE_EFI) {
+        qemuDomainNVRAMPathFormat(cfg, vm->def, &nvram_path);
+        need_deallocate_nvram_path = true;
+    } else {
+        if (vm->def->os.loader)
+            nvram_path = vm->def->os.loader->nvram;
+    }
+
+    if (nvram_path && virFileExists(nvram_path)) {
         if ((flags & VIR_DOMAIN_UNDEFINE_NVRAM)) {
-            if (unlink(vm->def->os.loader->nvram) < 0) {
+            if (unlink(nvram_path) < 0) {
                 virReportSystemError(errno,
                                      _("failed to remove nvram: %s"),
-                                     vm->def->os.loader->nvram);
+                                     nvram_path);
                 goto endjob;
             }
         } else if (!(flags & VIR_DOMAIN_UNDEFINE_KEEP_NVRAM)) {
@@ -7948,6 +7956,8 @@ qemuDomainUndefineFlags(virDomainPtr dom,
     virDomainObjEndAPI(&vm);
     virObjectEventStateQueue(driver->domainEventState, event);
     virObjectUnref(cfg);
+    if (need_deallocate_nvram_path)
+        VIR_FREE(nvram_path);
     return ret;
 }
 
-- 
2.21.0