From 7a3e5357cdd44f372dc8020395bdfd818d3453ed Mon Sep 17 00:00:00 2001

Message-Id: <7a3e5357cdd44f372dc8020395bdfd818d3453ed@dist-git>

From: Jiri Denemark <jdenemar@redhat.com>

Date: Fri, 16 Aug 2019 14:52:27 +0200

Subject: [PATCH] qemu: Pass qemuCaps to qemuDomainDefCopy

MIME-Version: 1.0

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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>

(cherry picked from commit a42f889591c16235e0fe349e509af896fa1ea5ff)

Conflicts:

	src/qemu/qemu_driver.c

            - context

https://bugzilla.redhat.com/show_bug.cgi?id=1731783

https://bugzilla.redhat.com/show_bug.cgi?id=1742023

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

Message-Id: <6ecee413894eadadaf37884be7dd4136ad2de403.1565959866.git.jdenemar@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/qemu/qemu_domain.c    | 16 ++++++++++------

 src/qemu/qemu_domain.h    |  2 ++

 src/qemu/qemu_driver.c    |  9 +++++----

 src/qemu/qemu_migration.c |  4 ++--

 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c

index 81699110fc..bf6013d42a 100644

--- a/src/qemu/qemu_domain.c

+++ b/src/qemu/qemu_domain.c

@@ -7203,6 +7203,7 @@ qemuDomainObjExitRemote(virDomainObjPtr obj,

 static virDomainDefPtr

 qemuDomainDefFromXML(virQEMUDriverPtr driver,

+                     virQEMUCapsPtr qemuCaps,

                      const char *xml)

 {

     virCapsPtr caps;

@@ -7211,7 +7212,7 @@ 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);

@@ -7222,6 +7223,7 @@ qemuDomainDefFromXML(virQEMUDriverPtr driver,

 virDomainDefPtr

 qemuDomainDefCopy(virQEMUDriverPtr driver,

+                  virQEMUCapsPtr qemuCaps,

                   virDomainDefPtr src,

                   unsigned int flags)

 {

@@ -7231,7 +7233,7 @@ 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;

@@ -9052,6 +9054,7 @@ qemuDomainMigratableDefCheckABIStability(virQEMUDriverPtr driver,

 bool

 qemuDomainDefCheckABIStability(virQEMUDriverPtr driver,

+                               virQEMUCapsPtr qemuCaps,

                                virDomainDefPtr src,

                                virDomainDefPtr dst)

 {

@@ -9059,8 +9062,8 @@ 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,

@@ -9079,14 +9082,15 @@ 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 cc406e3ca0..29283105cb 100644

--- a/src/qemu/qemu_domain.h

+++ b/src/qemu/qemu_domain.h

@@ -594,6 +594,7 @@ int qemuDomainObjExitRemote(virDomainObjPtr obj,

     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;

 virDomainDefPtr qemuDomainDefCopy(virQEMUDriverPtr driver,

+                                  virQEMUCapsPtr qemuCaps,

                                   virDomainDefPtr src,

                                   unsigned int flags);

@@ -769,6 +770,7 @@ 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 25818f5d8c..a486c66a5f 100644

--- a/src/qemu/qemu_driver.c

+++ b/src/qemu/qemu_driver.c

@@ -6325,7 +6325,7 @@ 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)))

@@ -16052,7 +16052,7 @@ qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,

     switch ((virDomainState) snap->def->state) {

     case VIR_DOMAIN_RUNNING:

     case VIR_DOMAIN_PAUSED:

-

+        priv = vm->privateData;

         start_flags |= VIR_QEMU_PROCESS_START_PAUSED;

         /* Transitions 2, 3, 5, 6, 8, 9 */

@@ -16079,7 +16079,9 @@ 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);

@@ -16123,7 +16125,6 @@ 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 67940330aa..4af105b997 100644

--- a/src/qemu/qemu_migration.c

+++ b/src/qemu/qemu_migration.c

@@ -2378,7 +2378,7 @@ qemuMigrationDstPrepareAny(virQEMUDriverPtr driver,

                 if (!newdef)

                     goto cleanup;

-                if (!qemuDomainDefCheckABIStability(driver, *def, newdef)) {

+                if (!qemuDomainDefCheckABIStability(driver, NULL, *def, newdef)) {

                     virDomainDefFree(newdef);

                     goto cleanup;

                 }

@@ -3417,7 +3417,7 @@ 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;

-- 

2.22.1