qemu: Pass qemuCaps to qemuDomainDefCopy

Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

This patch fixes all paths leading to qemuDomainDefCopy.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 0555caa6ab35806b05fb33fae476c14a0d70e429..dba5db68ecd60455024d7b680ca1c00a12326cb6 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -8361,6 +8361,7 @@ qemuDomainObjExitRemote(virDomainObjPtr obj,
 
 static virDomainDefPtr
 qemuDomainDefFromXML(virQEMUDriverPtr driver,
+                     virQEMUCapsPtr qemuCaps,
                      const char *xml)
 {
     virCapsPtr caps;
@@ -8369,7 +8370,7 @@ qemuDomainDefFromXML(virQEMUDriverPtr driver,
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         return NULL;
 
-    def = virDomainDefParseString(xml, caps, driver->xmlopt, NULL,
+    def = virDomainDefParseString(xml, caps, driver->xmlopt, qemuCaps,
                                   VIR_DOMAIN_DEF_PARSE_INACTIVE |
                                   VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE);
 
@@ -8380,6 +8381,7 @@ qemuDomainDefFromXML(virQEMUDriverPtr driver,
 
 virDomainDefPtr
 qemuDomainDefCopy(virQEMUDriverPtr driver,
+                  virQEMUCapsPtr qemuCaps,
                   virDomainDefPtr src,
                   unsigned int flags)
 {
@@ -8389,7 +8391,7 @@ qemuDomainDefCopy(virQEMUDriverPtr driver,
     if (!(xml = qemuDomainDefFormatXML(driver, src, flags)))
         return NULL;
 
-    ret = qemuDomainDefFromXML(driver, xml);
+    ret = qemuDomainDefFromXML(driver, qemuCaps, xml);
 
     VIR_FREE(xml);
     return ret;
@@ -10616,6 +10618,7 @@ qemuDomainMigratableDefCheckABIStability(virQEMUDriverPtr driver,
 
 bool
 qemuDomainDefCheckABIStability(virQEMUDriverPtr driver,
+                               virQEMUCapsPtr qemuCaps,
                                virDomainDefPtr src,
                                virDomainDefPtr dst)
 {
@@ -10623,8 +10626,8 @@ qemuDomainDefCheckABIStability(virQEMUDriverPtr driver,
     virDomainDefPtr migratableDefDst = NULL;
     bool ret = false;
 
-    if (!(migratableDefSrc = qemuDomainDefCopy(driver, src, COPY_FLAGS)) ||
-        !(migratableDefDst = qemuDomainDefCopy(driver, dst, COPY_FLAGS)))
+    if (!(migratableDefSrc = qemuDomainDefCopy(driver, qemuCaps, src, COPY_FLAGS)) ||
+        !(migratableDefDst = qemuDomainDefCopy(driver, qemuCaps, dst, COPY_FLAGS)))
         goto cleanup;
 
     ret = qemuDomainMigratableDefCheckABIStability(driver,
@@ -10643,14 +10646,15 @@ qemuDomainCheckABIStability(virQEMUDriverPtr driver,
                             virDomainObjPtr vm,
                             virDomainDefPtr dst)
 {
+    qemuDomainObjPrivatePtr priv = vm->privateData;
     virDomainDefPtr migratableSrc = NULL;
     virDomainDefPtr migratableDst = NULL;
     char *xml = NULL;
     bool ret = false;
 
     if (!(xml = qemuDomainFormatXML(driver, vm, COPY_FLAGS)) ||
-        !(migratableSrc = qemuDomainDefFromXML(driver, xml)) ||
-        !(migratableDst = qemuDomainDefCopy(driver, dst, COPY_FLAGS)))
+        !(migratableSrc = qemuDomainDefFromXML(driver, priv->qemuCaps, xml)) ||
+        !(migratableDst = qemuDomainDefCopy(driver, priv->qemuCaps, dst, COPY_FLAGS)))
         goto cleanup;
 
     ret = qemuDomainMigratableDefCheckABIStability(driver,

diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index b76d3cace9245c19fe9c32a9c930aacc279efbef..94ff6e7bd3bd99c1cef091f03fdb70ace9bcd7ba 100644 (file)
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -649,6 +649,7 @@ int qemuDomainObjExitRemote(virDomainObjPtr obj,
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
 
 virDomainDefPtr qemuDomainDefCopy(virQEMUDriverPtr driver,
+                                  virQEMUCapsPtr qemuCaps,
                                   virDomainDefPtr src,
                                   unsigned int flags);
 
@@ -863,6 +864,7 @@ int qemuDomainUpdateMemoryDeviceInfo(virQEMUDriverPtr driver,
                                      int asyncJob);
 
 bool qemuDomainDefCheckABIStability(virQEMUDriverPtr driver,
+                                    virQEMUCapsPtr qemuCaps,
                                     virDomainDefPtr src,
                                     virDomainDefPtr dst);
 

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ff83d1c02420cd1dc966c36a4a13a5383739deb0..4d6a9332436a011d84f19b7ed0b1d1342a47d543 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -6764,7 +6764,7 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
                                            VIR_DOMAIN_DEF_PARSE_INACTIVE)))
         goto cleanup;
 
-    if (!(newdef_migr = qemuDomainDefCopy(driver,
+    if (!(newdef_migr = qemuDomainDefCopy(driver, NULL,
                                           newdef,
                                           QEMU_DOMAIN_FORMAT_LIVE_FLAGS |
                                           VIR_DOMAIN_XML_MIGRATABLE)))
@@ -16553,7 +16553,7 @@ qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
     switch ((virDomainSnapshotState) snapdef->state) {
     case VIR_DOMAIN_SNAPSHOT_RUNNING:
     case VIR_DOMAIN_SNAPSHOT_PAUSED:
-
+        priv = vm->privateData;
         start_flags |= VIR_QEMU_PROCESS_START_PAUSED;
 
         /* Transitions 2, 3, 5, 6, 8, 9 */
@@ -16580,7 +16580,9 @@ qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                     if (!(config->cpu = virCPUDefCopy(cookie->cpu)))
                         goto endjob;
 
-                    compatible = qemuDomainDefCheckABIStability(driver, vm->def,
+                    compatible = qemuDomainDefCheckABIStability(driver,
+                                                                priv->qemuCaps,
+                                                                vm->def,
                                                                 config);
                 } else {
                     compatible = qemuDomainCheckABIStability(driver, vm, config);
@@ -16624,7 +16626,6 @@ qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                 }
             }
 
-            priv = vm->privateData;
             if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING) {
                 /* Transitions 5, 6 */
                 if (qemuProcessStopCPUs(driver, vm,

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 7c6be201b9d355d933a14f9405db14c94a2071f8..ec1cae8beca39d26aaf19fe1a80b3d9774089d39 100644 (file)
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2381,7 +2381,7 @@ qemuMigrationDstPrepareAny(virQEMUDriverPtr driver,
                 if (!newdef)
                     goto cleanup;
 
-                if (!qemuDomainDefCheckABIStability(driver, *def, newdef)) {
+                if (!qemuDomainDefCheckABIStability(driver, NULL, *def, newdef)) {
                     virDomainDefFree(newdef);
                     goto cleanup;
                 }
@@ -3427,7 +3427,7 @@ qemuMigrationSrcRun(virQEMUDriverPtr driver,
                 goto error;
         } else {
             virDomainDefPtr def = vm->newDef ? vm->newDef : vm->def;
-            if (!(persistDef = qemuDomainDefCopy(driver, def,
+            if (!(persistDef = qemuDomainDefCopy(driver, priv->qemuCaps, def,
                                                  VIR_DOMAIN_XML_SECURE |
                                                  VIR_DOMAIN_XML_MIGRATABLE)))
                 goto error;