From b900f7387fca1cf3567935c81136579d6bee95ca Mon Sep 17 00:00:00 2001
From: Jiri Denemark <jdenemar@redhat.com>
Date: Mon, 5 Aug 2019 17:31:10 +0200
Subject: [PATCH] qemu: Pass qemuCaps to qemuMigrationAnyPrepareDef

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 qemuMigrationAnyPrepareDef.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/qemu/qemu_driver.c    | 12 ++++++------
 src/qemu/qemu_migration.c |  8 ++++++--
 src/qemu/qemu_migration.h |  1 +
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 14a20029dd..1139fde77a 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -12651,7 +12651,7 @@ qemuDomainMigratePrepareTunnel(virConnectPtr dconn,
         goto cleanup;
     }
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepareTunnelEnsureACL(dconn, def) < 0)
@@ -12712,7 +12712,7 @@ qemuDomainMigratePrepare2(virConnectPtr dconn,
         goto cleanup;
     }
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepare2EnsureACL(dconn, def) < 0)
@@ -12951,7 +12951,7 @@ qemuDomainMigratePrepare3(virConnectPtr dconn,
                                                    QEMU_MIGRATION_DESTINATION)))
         goto cleanup;
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepare3EnsureACL(dconn, def) < 0)
@@ -13038,7 +13038,7 @@ qemuDomainMigratePrepare3Params(virConnectPtr dconn,
         goto cleanup;
     }
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepare3ParamsEnsureACL(dconn, def) < 0)
@@ -13092,7 +13092,7 @@ qemuDomainMigratePrepareTunnel3(virConnectPtr dconn,
                                                    QEMU_MIGRATION_DESTINATION)))
         goto cleanup;
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepareTunnel3EnsureACL(dconn, def) < 0)
@@ -13151,7 +13151,7 @@ qemuDomainMigratePrepareTunnel3Params(virConnectPtr dconn,
                                                    QEMU_MIGRATION_DESTINATION)))
         goto cleanup;
 
-    if (!(def = qemuMigrationAnyPrepareDef(driver, dom_xml, dname, &origname)))
+    if (!(def = qemuMigrationAnyPrepareDef(driver, NULL, dom_xml, dname, &origname)))
         goto cleanup;
 
     if (virDomainMigratePrepareTunnel3ParamsEnsureACL(dconn, def) < 0)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 39e574ee30..d07482d9f2 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2861,6 +2861,7 @@ qemuMigrationDstPrepareDirect(virQEMUDriverPtr driver,
 
 virDomainDefPtr
 qemuMigrationAnyPrepareDef(virQEMUDriverPtr driver,
+                           virQEMUCapsPtr qemuCaps,
                            const char *dom_xml,
                            const char *dname,
                            char **origname)
@@ -2878,7 +2879,8 @@ qemuMigrationAnyPrepareDef(virQEMUDriverPtr driver,
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         return NULL;
 
-    if (!(def = virDomainDefParseString(dom_xml, caps, driver->xmlopt, NULL,
+    if (!(def = virDomainDefParseString(dom_xml, caps, driver->xmlopt,
+                                        qemuCaps,
                                         VIR_DOMAIN_DEF_PARSE_INACTIVE |
                                         VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE)))
         goto cleanup;
@@ -3422,7 +3424,9 @@ qemuMigrationSrcRun(virQEMUDriverPtr driver,
 
     if (flags & VIR_MIGRATE_PERSIST_DEST) {
         if (persist_xml) {
-            if (!(persistDef = qemuMigrationAnyPrepareDef(driver, persist_xml,
+            if (!(persistDef = qemuMigrationAnyPrepareDef(driver,
+                                                          priv->qemuCaps,
+                                                          persist_xml,
                                                           NULL, NULL)))
                 goto error;
         } else {
diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h
index bea7b1e688..188ccfa7fd 100644
--- a/src/qemu/qemu_migration.h
+++ b/src/qemu/qemu_migration.h
@@ -115,6 +115,7 @@ qemuMigrationSrcBegin(virConnectPtr conn,
 
 virDomainDefPtr
 qemuMigrationAnyPrepareDef(virQEMUDriverPtr driver,
+                           virQEMUCapsPtr qemuCaps,
                            const char *dom_xml,
                            const char *dname,
                            char **origname);