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-rw-r--r--.cirrus.yml6
-rw-r--r--.shippable.yml12
-rw-r--r--Makefile16
-rw-r--r--accel/tcg/cputlb.c15
-rw-r--r--accel/tcg/translate-all.c17
-rwxr-xr-xconfigure48
-rw-r--r--cpus-common.c25
-rw-r--r--cpus.c14
-rw-r--r--docs/devel/testing.rst107
m---------dtc0
-rw-r--r--exec.c1
-rw-r--r--hw/core/cpu.c1
-rw-r--r--include/exec/exec-all.h8
-rw-r--r--include/hw/core/cpu.h6
-rw-r--r--include/qemu/thread.h38
-rw-r--r--include/qemu/tsan.h71
-rw-r--r--include/tcg/tcg.h1
-rw-r--r--tcg/tcg.c9
-rw-r--r--tests/Makefile.include9
-rw-r--r--tests/docker/dockerfiles/fedora.docker2
-rw-r--r--tests/docker/dockerfiles/ubuntu2004.docker65
-rwxr-xr-xtests/docker/test-tsan44
-rw-r--r--tests/plugin/Makefile1
-rw-r--r--tests/plugin/lockstep.c340
-rw-r--r--tests/qtest/Makefile.include7
-rw-r--r--tests/tcg/Makefile.target12
-rw-r--r--tests/tcg/aarch64/Makefile.target5
-rw-r--r--tests/tcg/arm/Makefile.target2
-rw-r--r--tests/tcg/i386/Makefile.target1
-rw-r--r--tests/tsan/blacklist.tsan10
-rw-r--r--tests/tsan/suppressions.tsan14
-rw-r--r--util/coroutine-ucontext.c66
-rw-r--r--util/qemu-thread-posix.c2
-rw-r--r--util/qht.c1
34 files changed, 909 insertions, 67 deletions
diff --git a/.cirrus.yml b/.cirrus.yml
index ce7850a320..69342ae031 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -14,7 +14,7 @@ freebsd_12_task:
     - cd build
     - ../configure || { cat config.log; exit 1; }
     - gmake -j8
-    - gmake -j8 V=1 check
+    - gmake V=1 check
 
 macos_task:
   osx_instance:
@@ -26,7 +26,7 @@ macos_task:
     - cd build
     - ../configure --python=/usr/local/bin/python3 || { cat config.log; exit 1; }
     - gmake -j$(sysctl -n hw.ncpu)
-    - gmake check -j$(sysctl -n hw.ncpu)
+    - gmake check
 
 macos_xcode_task:
   osx_instance:
@@ -39,4 +39,4 @@ macos_xcode_task:
     - cd build
     - ../configure --cc=clang || { cat config.log; exit 1; }
     - gmake -j$(sysctl -n hw.ncpu)
-    - gmake check -j$(sysctl -n hw.ncpu)
+    - gmake check
diff --git a/.shippable.yml b/.shippable.yml
index 10cf219bff..2cce7b5689 100644
--- a/.shippable.yml
+++ b/.shippable.yml
@@ -5,8 +5,8 @@ env:
   global:
     - LC_ALL=C
   matrix:
-    # - IMAGE=debian-amd64
-    #   TARGET_LIST=x86_64-softmmu,x86_64-linux-user
+    - IMAGE=debian-amd64
+      TARGET_LIST=x86_64-softmmu,x86_64-linux-user
     - IMAGE=debian-win32-cross
       TARGET_LIST=arm-softmmu,i386-softmmu,lm32-softmmu
     - IMAGE=debian-win64-cross
@@ -19,10 +19,10 @@ env:
       TARGET_LIST=aarch64-softmmu,aarch64-linux-user
     - IMAGE=debian-s390x-cross
       TARGET_LIST=s390x-softmmu,s390x-linux-user
-    # - IMAGE=debian-mips-cross
-    #   TARGET_LIST=mips-softmmu,mipsel-linux-user
-    # - IMAGE=debian-mips64el-cross
-    #   TARGET_LIST=mips64el-softmmu,mips64el-linux-user
+    - IMAGE=debian-mips-cross
+      TARGET_LIST=mips-softmmu,mipsel-linux-user
+    - IMAGE=debian-mips64el-cross
+      TARGET_LIST=mips64el-softmmu,mips64el-linux-user
     - IMAGE=debian-ppc64el-cross
       TARGET_LIST=ppc64-softmmu,ppc64-linux-user,ppc64abi32-linux-user
 build:
diff --git a/Makefile b/Makefile
index ed0ed93b2d..48f23aa978 100644
--- a/Makefile
+++ b/Makefile
@@ -526,13 +526,14 @@ $(SOFTMMU_FUZZ_RULES): $(edk2-decompressed)
 $(TARGET_DIRS_RULES):
 	$(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C $(dir $@) V="$(V)" TARGET_DIR="$(dir $@)" $(notdir $@),)
 
-DTC_MAKE_ARGS=-I$(SRC_PATH)/dtc VPATH=$(SRC_PATH)/dtc -C dtc V="$(V)" LIBFDT_srcdir=$(SRC_PATH)/dtc/libfdt
+# LIBFDT_lib="": avoid breaking existing trees with objects requiring -fPIC
+DTC_MAKE_ARGS=-I$(SRC_PATH)/dtc VPATH=$(SRC_PATH)/dtc -C dtc V="$(V)" LIBFDT_lib=""
 DTC_CFLAGS=$(CFLAGS) $(QEMU_CFLAGS)
-DTC_CPPFLAGS=-I$(BUILD_DIR)/dtc -I$(SRC_PATH)/dtc -I$(SRC_PATH)/dtc/libfdt
+DTC_CPPFLAGS=-I$(SRC_PATH)/dtc/libfdt
 
 .PHONY: dtc/all
-dtc/all: .git-submodule-status dtc/libfdt dtc/tests
-	$(call quiet-command,$(MAKE) $(DTC_MAKE_ARGS) CPPFLAGS="$(DTC_CPPFLAGS)" CFLAGS="$(DTC_CFLAGS)" LDFLAGS="$(QEMU_LDFLAGS)" ARFLAGS="$(ARFLAGS)" CC="$(CC)" AR="$(AR)" LD="$(LD)" $(SUBDIR_MAKEFLAGS) libfdt/libfdt.a,)
+dtc/all: .git-submodule-status dtc/libfdt
+	$(call quiet-command,$(MAKE) $(DTC_MAKE_ARGS) CPPFLAGS="$(DTC_CPPFLAGS)" CFLAGS="$(DTC_CFLAGS)" LDFLAGS="$(QEMU_LDFLAGS)" ARFLAGS="$(ARFLAGS)" CC="$(CC)" AR="$(AR)" LD="$(LD)" $(SUBDIR_MAKEFLAGS) libfdt,)
 
 dtc/%: .git-submodule-status
 	@mkdir -p $@
@@ -561,12 +562,6 @@ slirp/all: .git-submodule-status
 		CC="$(CC)" AR="$(AR)" 	LD="$(LD)" RANLIB="$(RANLIB)"	\
 		CFLAGS="$(QEMU_CFLAGS) $(CFLAGS)" LDFLAGS="$(QEMU_LDFLAGS)")
 
-# Compatibility gunk to keep make working across the rename of targets
-# for recursion, to be removed some time after 4.1.
-subdir-dtc: dtc/all
-subdir-capstone: capstone/all
-subdir-slirp: slirp/all
-
 $(filter %/all, $(TARGET_DIRS_RULES)): libqemuutil.a $(common-obj-y) \
 	$(qom-obj-y)
 
@@ -820,7 +815,6 @@ distclean: clean
 	rm -rf $$d || exit 1 ; \
         done
 	rm -Rf .sdk
-	if test -f dtc/version_gen.h; then $(MAKE) $(DTC_MAKE_ARGS) clean; fi
 
 KEYMAPS=da     en-gb  et  fr     fr-ch  is  lt  no  pt-br  sv \
 ar      de     en-us  fi  fr-be  hr     it  lv  nl         pl  ru     th \
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index eb2cf9de5e..1e815357c7 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -270,6 +270,21 @@ void tlb_init(CPUState *cpu)
     }
 }
 
+void tlb_destroy(CPUState *cpu)
+{
+    CPUArchState *env = cpu->env_ptr;
+    int i;
+
+    qemu_spin_destroy(&env_tlb(env)->c.lock);
+    for (i = 0; i < NB_MMU_MODES; i++) {
+        CPUTLBDesc *desc = &env_tlb(env)->d[i];
+        CPUTLBDescFast *fast = &env_tlb(env)->f[i];
+
+        g_free(fast->table);
+        g_free(desc->iotlb);
+    }
+}
+
 /* flush_all_helper: run fn across all cpus
  *
  * If the wait flag is set then the src cpu's helper will be queued as
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 42ce1dfcff..c3d37058a1 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -384,6 +384,11 @@ static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb,
     return 0;
 }
 
+void tb_destroy(TranslationBlock *tb)
+{
+    qemu_spin_destroy(&tb->jmp_lock);
+}
+
 bool cpu_restore_state(CPUState *cpu, uintptr_t host_pc, bool will_exit)
 {
     TranslationBlock *tb;
@@ -413,6 +418,7 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t host_pc, bool will_exit)
                 /* one-shot translation, invalidate it immediately */
                 tb_phys_invalidate(tb, -1);
                 tcg_tb_remove(tb);
+                tb_destroy(tb);
             }
             r = true;
         }
@@ -541,6 +547,15 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
 #endif
         existing = atomic_cmpxchg(lp, NULL, pd);
         if (unlikely(existing)) {
+#ifndef CONFIG_USER_ONLY
+            {
+                int i;
+
+                for (i = 0; i < V_L2_SIZE; i++) {
+                    qemu_spin_destroy(&pd[i].lock);
+                }
+            }
+#endif
             g_free(pd);
             pd = existing;
         }
@@ -1886,6 +1901,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
 
         orig_aligned -= ROUND_UP(sizeof(*tb), qemu_icache_linesize);
         atomic_set(&tcg_ctx->code_gen_ptr, (void *)orig_aligned);
+        tb_destroy(tb);
         return existing_tb;
     }
     tcg_tb_insert(tb);
@@ -2235,6 +2251,7 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
             tb_phys_invalidate(tb->orig_tb, -1);
         }
         tcg_tb_remove(tb);
+        tb_destroy(tb);
     }
 
     /* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not
diff --git a/configure b/configure
index 89867a1720..b01b5e3bed 100755
--- a/configure
+++ b/configure
@@ -395,6 +395,7 @@ gprof="no"
 debug_tcg="no"
 debug="no"
 sanitizers="no"
+tsan="no"
 fortify_source=""
 strip_opt="yes"
 tcg_interpreter="no"
@@ -1152,6 +1153,10 @@ for opt do
   ;;
   --disable-sanitizers) sanitizers="no"
   ;;
+  --enable-tsan) tsan="yes"
+  ;;
+  --disable-tsan) tsan="no"
+  ;;
   --enable-sparse) sparse="yes"
   ;;
   --disable-sparse) sparse="no"
@@ -1764,6 +1769,7 @@ Advanced options (experts only):
   --with-pkgversion=VERS   use specified string as sub-version of the package
   --enable-debug           enable common debug build options
   --enable-sanitizers      enable default sanitizers
+  --enable-tsan            enable thread sanitizer
   --disable-strip          disable stripping binaries
   --disable-werror         disable compilation abort on warning
   --disable-stack-protector disable compiler-provided stack protection
@@ -4312,7 +4318,6 @@ EOF
           mkdir -p dtc
           if [ "$pwd_is_source_path" != "y" ] ; then
               symlink "$source_path/dtc/Makefile" "dtc/Makefile"
-              symlink "$source_path/dtc/scripts" "dtc/scripts"
           fi
           fdt_cflags="-I\$(SRC_PATH)/dtc/libfdt"
           fdt_ldflags="-L\$(BUILD_DIR)/dtc/libfdt"
@@ -6221,6 +6226,30 @@ if test "$fuzzing" = "yes" ; then
   fi
 fi
 
+# Thread sanitizer is, for now, much noisier than the other sanitizers;
+# keep it separate until that is not the case.
+if test "$tsan" = "yes" && test "$sanitizers" = "yes"; then
+  error_exit "TSAN is not supported with other sanitiziers."
+fi
+have_tsan=no
+have_tsan_iface_fiber=no
+if test "$tsan" = "yes" ; then
+  write_c_skeleton
+  if compile_prog "$CPU_CFLAGS -Werror -fsanitize=thread" "" ; then
+      have_tsan=yes
+  fi
+  cat > $TMPC << EOF
+#include <sanitizer/tsan_interface.h>
+int main(void) {
+  __tsan_create_fiber(0);
+  return 0;
+}
+EOF
+  if compile_prog "$CPU_CFLAGS -Werror -fsanitize=thread" "" ; then
+      have_tsan_iface_fiber=yes
+  fi
+fi
+
 ##########################################
 # check for libpmem
 
@@ -6378,6 +6407,16 @@ if test "$have_asan" = "yes"; then
            "Without code annotation, the report may be inferior."
   fi
 fi
+if test "$have_tsan" = "yes" ; then
+  if test "$have_tsan_iface_fiber" = "yes" ; then
+    QEMU_CFLAGS="-fsanitize=thread $QEMU_CFLAGS"
+    QEMU_LDFLAGS="-fsanitize=thread $QEMU_LDFLAGS"
+  else
+    error_exit "Cannot enable TSAN due to missing fiber annotation interface."
+  fi
+elif test "$tsan" = "yes" ; then
+  error_exit "Cannot enable TSAN due to missing sanitize thread interface."
+fi
 if test "$have_ubsan" = "yes"; then
   QEMU_CFLAGS="-fsanitize=undefined $QEMU_CFLAGS"
   QEMU_LDFLAGS="-fsanitize=undefined $QEMU_LDFLAGS"
@@ -6413,7 +6452,8 @@ if test "$werror" = "yes"; then
     QEMU_CFLAGS="-Werror $QEMU_CFLAGS"
 fi
 
-if test "$solaris" = "no" ; then
+# Exclude --warn-common with TSan to suppress warnings from the TSan libraries.
+if test "$solaris" = "no" && test "$tsan" = "no"; then
     if $ld --version 2>/dev/null | grep "GNU ld" >/dev/null 2>/dev/null ; then
         QEMU_LDFLAGS="-Wl,--warn-common $QEMU_LDFLAGS"
     fi
@@ -7477,6 +7517,10 @@ if test "$have_asan_iface_fiber" = "yes" ; then
     echo "CONFIG_ASAN_IFACE_FIBER=y" >> $config_host_mak
 fi
 
+if test "$have_tsan" = "yes" && test "$have_tsan_iface_fiber" = "yes" ; then
+    echo "CONFIG_TSAN=y" >> $config_host_mak
+fi
+
 if test "$has_environ" = "yes" ; then
   echo "CONFIG_HAS_ENVIRON=y" >> $config_host_mak
 fi
diff --git a/cpus-common.c b/cpus-common.c
index 70a9d12981..8f5512b3d7 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -97,7 +97,7 @@ void cpu_list_remove(CPUState *cpu)
 }
 
 struct qemu_work_item {
-    struct qemu_work_item *next;
+    QSIMPLEQ_ENTRY(qemu_work_item) node;
     run_on_cpu_func func;
     run_on_cpu_data data;
     bool free, exclusive, done;
@@ -106,13 +106,7 @@ struct qemu_work_item {
 static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi)
 {
     qemu_mutex_lock(&cpu->work_mutex);
-    if (cpu->queued_work_first == NULL) {
-        cpu->queued_work_first = wi;
-    } else {
-        cpu->queued_work_last->next = wi;
-    }
-    cpu->queued_work_last = wi;
-    wi->next = NULL;
+    QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node);
     wi->done = false;
     qemu_mutex_unlock(&cpu->work_mutex);
 
@@ -306,17 +300,14 @@ void process_queued_cpu_work(CPUState *cpu)
 {
     struct qemu_work_item *wi;
 
-    if (cpu->queued_work_first == NULL) {
+    qemu_mutex_lock(&cpu->work_mutex);
+    if (QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        qemu_mutex_unlock(&cpu->work_mutex);
         return;
     }
-
-    qemu_mutex_lock(&cpu->work_mutex);
-    while (cpu->queued_work_first != NULL) {
-        wi = cpu->queued_work_first;
-        cpu->queued_work_first = wi->next;
-        if (!cpu->queued_work_first) {
-            cpu->queued_work_last = NULL;
-        }
+    while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        wi = QSIMPLEQ_FIRST(&cpu->work_list);
+        QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);
         qemu_mutex_unlock(&cpu->work_mutex);
         if (wi->exclusive) {
             /* Running work items outside the BQL avoids the following deadlock:
diff --git a/cpus.c b/cpus.c
index 34fc203808..7317ae06b9 100644
--- a/cpus.c
+++ b/cpus.c
@@ -97,9 +97,19 @@ bool cpu_is_stopped(CPUState *cpu)
     return cpu->stopped || !runstate_is_running();
 }
 
+static inline bool cpu_work_list_empty(CPUState *cpu)
+{
+    bool ret;
+
+    qemu_mutex_lock(&cpu->work_mutex);
+    ret = QSIMPLEQ_EMPTY(&cpu->work_list);
+    qemu_mutex_unlock(&cpu->work_mutex);
+    return ret;
+}
+
 static bool cpu_thread_is_idle(CPUState *cpu)
 {
-    if (cpu->stop || cpu->queued_work_first) {
+    if (cpu->stop || !cpu_work_list_empty(cpu)) {
         return false;
     }
     if (cpu_is_stopped(cpu)) {
@@ -1518,7 +1528,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
             cpu = first_cpu;
         }
 
-        while (cpu && !cpu->queued_work_first && !cpu->exit_request) {
+        while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) {
 
             atomic_mb_set(&tcg_current_rr_cpu, cpu);
             current_cpu = cpu;
diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 770a987ea4..c1ff24370b 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -397,6 +397,113 @@ list is in the ``make docker`` help text. The frequently used ones are:
 * ``DEBUG=1``: enables debug. See the previous "Debugging a Docker test
   failure" section.
 
+Thread Sanitizer
+================
+
+Thread Sanitizer (TSan) is a tool which can detect data races.  QEMU supports
+building and testing with this tool.
+
+For more information on TSan:
+
+https://github.com/google/sanitizers/wiki/ThreadSanitizerCppManual
+
+Thread Sanitizer in Docker
+---------------------------
+TSan is currently supported in the ubuntu2004 docker.
+
+The test-tsan test will build using TSan and then run make check.
+
+.. code::
+
+  make docker-test-tsan@ubuntu2004
+
+TSan warnings under docker are placed in files located at build/tsan/.
+
+We recommend using DEBUG=1 to allow launching the test from inside the docker,
+and to allow review of the warnings generated by TSan.
+
+Building and Testing with TSan
+------------------------------
+
+It is possible to build and test with TSan, with a few additional steps.
+These steps are normally done automatically in the docker.
+
+There is a one time patch needed in clang-9 or clang-10 at this time:
+
+.. code::
+
+  sed -i 's/^const/static const/g' \
+      /usr/lib/llvm-10/lib/clang/10.0.0/include/sanitizer/tsan_interface.h
+
+To configure the build for TSan:
+
+.. code::
+
+  ../configure --enable-tsan --cc=clang-10 --cxx=clang++-10 \
+               --disable-werror --extra-cflags="-O0"
+
+The runtime behavior of TSAN is controlled by the TSAN_OPTIONS environment
+variable.
+
+More information on the TSAN_OPTIONS can be found here:
+
+https://github.com/google/sanitizers/wiki/ThreadSanitizerFlags
+
+For example:
+
+.. code::
+
+  export TSAN_OPTIONS=suppressions=<path to qemu>/tests/tsan/suppressions.tsan \
+                      detect_deadlocks=false history_size=7 exitcode=0 \
+                      log_path=<build path>/tsan/tsan_warning
+
+The above exitcode=0 has TSan continue without error if any warnings are found.
+This allows for running the test and then checking the warnings afterwards.
+If you want TSan to stop and exit with error on warnings, use exitcode=66.
+
+TSan Suppressions
+-----------------
+Keep in mind that for any data race warning, although there might be a data race
+detected by TSan, there might be no actual bug here.  TSan provides several
+different mechanisms for suppressing warnings.  In general it is recommended
+to fix the code if possible to eliminate the data race rather than suppress
+the warning.
+
+A few important files for suppressing warnings are:
+
+tests/tsan/suppressions.tsan - Has TSan warnings we wish to suppress at runtime.
+The comment on each supression will typically indicate why we are
+suppressing it.  More information on the file format can be found here:
+
+https://github.com/google/sanitizers/wiki/ThreadSanitizerSuppressions
+
+tests/tsan/blacklist.tsan - Has TSan warnings we wish to disable
+at compile time for test or debug.
+Add flags to configure to enable:
+
+"--extra-cflags=-fsanitize-blacklist=<src path>/tests/tsan/blacklist.tsan"
+
+More information on the file format can be found here under "Blacklist Format":
+
+https://github.com/google/sanitizers/wiki/ThreadSanitizerFlags
+
+TSan Annotations
+----------------
+include/qemu/tsan.h defines annotations.  See this file for more descriptions
+of the annotations themselves.  Annotations can be used to suppress
+TSan warnings or give TSan more information so that it can detect proper
+relationships between accesses of data.
+
+Annotation examples can be found here:
+
+https://github.com/llvm/llvm-project/tree/master/compiler-rt/test/tsan/
+
+Good files to start with are: annotate_happens_before.cpp and ignore_race.cpp
+
+The full set of annotations can be found here:
+
+https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp
+
 VM testing
 ==========
 
diff --git a/dtc b/dtc
-Subproject 88f18909db731a627456f26d779445f84e44953
+Subproject 85e5d839847af54efab170f2b1331b2a6421e64
diff --git a/exec.c b/exec.c
index 9c8f558590..d6712fba7e 100644
--- a/exec.c
+++ b/exec.c
@@ -892,6 +892,7 @@ void cpu_exec_unrealizefn(CPUState *cpu)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
 
+    tlb_destroy(cpu);
     cpu_list_remove(cpu);
 
     if (cc->vmsd != NULL) {
diff --git a/hw/core/cpu.c b/hw/core/cpu.c
index 4d5438b70e..0f23409f1d 100644
--- a/hw/core/cpu.c
+++ b/hw/core/cpu.c
@@ -370,6 +370,7 @@ static void cpu_common_initfn(Object *obj)
     cpu->nr_threads = 1;
 
     qemu_mutex_init(&cpu->work_mutex);
+    QSIMPLEQ_INIT(&cpu->work_list);
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
 
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 8792bea07a..3cf88272df 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -125,6 +125,11 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
  */
 void tlb_init(CPUState *cpu);
 /**
+ * tlb_destroy - destroy a CPU's TLB
+ * @cpu: CPU whose TLB should be destroyed
+ */
+void tlb_destroy(CPUState *cpu);
+/**
  * tlb_flush_page:
  * @cpu: CPU whose TLB should be flushed
  * @addr: virtual address of page to be flushed
@@ -284,6 +289,9 @@ void tlb_set_page(CPUState *cpu, target_ulong vaddr,
 static inline void tlb_init(CPUState *cpu)
 {
 }
+static inline void tlb_destroy(CPUState *cpu)
+{
+}
 static inline void tlb_flush_page(CPUState *cpu, target_ulong addr)
 {
 }
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 497600c49e..b3f4b79318 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -331,8 +331,8 @@ struct qemu_work_item;
  * @opaque: User data.
  * @mem_io_pc: Host Program Counter at which the memory was accessed.
  * @kvm_fd: vCPU file descriptor for KVM.
- * @work_mutex: Lock to prevent multiple access to queued_work_*.
- * @queued_work_first: First asynchronous work pending.
+ * @work_mutex: Lock to prevent multiple access to @work_list.
+ * @work_list: List of pending asynchronous work.
  * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes
  *                        to @trace_dstate).
  * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).
@@ -376,7 +376,7 @@ struct CPUState {
     sigjmp_buf jmp_env;
 
     QemuMutex work_mutex;
-    struct qemu_work_item *queued_work_first, *queued_work_last;
+    QSIMPLEQ_HEAD(, qemu_work_item) work_list;
 
     CPUAddressSpace *cpu_ases;
     int num_ases;
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index 06c058fb58..4baf4d1715 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -206,6 +206,10 @@ void qemu_thread_atexit_add(struct Notifier *notifier);
  */
 void qemu_thread_atexit_remove(struct Notifier *notifier);
 
+#ifdef CONFIG_TSAN
+#include <sanitizer/tsan_interface.h>
+#endif
+
 struct QemuSpin {
     int value;
 };
@@ -213,20 +217,46 @@ struct QemuSpin {
 static inline void qemu_spin_init(QemuSpin *spin)
 {
     __sync_lock_release(&spin->value);
+#ifdef CONFIG_TSAN
+    __tsan_mutex_create(spin, __tsan_mutex_not_static);
+#endif
+}
+
+/* const parameter because the only purpose here is the TSAN annotation */
+static inline void qemu_spin_destroy(const QemuSpin *spin)
+{
+#ifdef CONFIG_TSAN
+    __tsan_mutex_destroy((void *)spin, __tsan_mutex_not_static);
+#endif
 }
 
 static inline void qemu_spin_lock(QemuSpin *spin)
 {
+#ifdef CONFIG_TSAN
+    __tsan_mutex_pre_lock(spin, 0);
+#endif
     while (unlikely(__sync_lock_test_and_set(&spin->value, true))) {
         while (atomic_read(&spin->value)) {
             cpu_relax();
         }
     }
+#ifdef CONFIG_TSAN
+    __tsan_mutex_post_lock(spin, 0, 0);
+#endif
 }
 
 static inline bool qemu_spin_trylock(QemuSpin *spin)
 {
-    return __sync_lock_test_and_set(&spin->value, true);
+#ifdef CONFIG_TSAN
+    __tsan_mutex_pre_lock(spin, __tsan_mutex_try_lock);
+#endif
+    bool busy = __sync_lock_test_and_set(&spin->value, true);
+#ifdef CONFIG_TSAN
+    unsigned flags = __tsan_mutex_try_lock;
+    flags |= busy ? __tsan_mutex_try_lock_failed : 0;
+    __tsan_mutex_post_lock(spin, flags, 0);
+#endif
+    return busy;
 }
 
 static inline bool qemu_spin_locked(QemuSpin *spin)
@@ -236,7 +266,13 @@ static inline bool qemu_spin_locked(QemuSpin *spin)
 
 static inline void qemu_spin_unlock(QemuSpin *spin)
 {
+#ifdef CONFIG_TSAN
+    __tsan_mutex_pre_unlock(spin, 0);
+#endif
     __sync_lock_release(&spin->value);
+#ifdef CONFIG_TSAN
+    __tsan_mutex_post_unlock(spin, 0);
+#endif
 }
 
 struct QemuLockCnt {
diff --git a/include/qemu/tsan.h b/include/qemu/tsan.h
new file mode 100644
index 0000000000..09cc665f91
--- /dev/null
+++ b/include/qemu/tsan.h
@@ -0,0 +1,71 @@
+#ifndef QEMU_TSAN_H
+#define QEMU_TSAN_H
+/*
+ * tsan.h
+ *
+ * This file defines macros used to give ThreadSanitizer
+ * additional information to help suppress warnings.
+ * This is necessary since TSan does not provide a header file
+ * for these annotations.  The standard way to include these
+ * is via the below macros.
+ *
+ * Annotation examples can be found here:
+ *  https://github.com/llvm/llvm-project/tree/master/compiler-rt/test/tsan
+ * annotate_happens_before.cpp or ignore_race.cpp are good places to start.
+ *
+ * The full set of annotations can be found here in tsan_interface_ann.cpp.
+ *  https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/tsan/rtl/
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifdef CONFIG_TSAN
+/*
+ * Informs TSan of a happens before/after relationship.
+ */
+#define QEMU_TSAN_ANNOTATE_HAPPENS_BEFORE(addr) \
+    AnnotateHappensBefore(__FILE__, __LINE__, (void *)(addr))
+#define QEMU_TSAN_ANNOTATE_HAPPENS_AFTER(addr) \
+    AnnotateHappensAfter(__FILE__, __LINE__, (void *)(addr))
+/*
+ * Gives TSan more information about thread names it can report the
+ * name of the thread in the warning report.
+ */
+#define QEMU_TSAN_ANNOTATE_THREAD_NAME(name) \
+    AnnotateThreadName(__FILE__, __LINE__, (void *)(name))
+/*
+ * Allows defining a region of code on which TSan will not record memory READS.
+ * This has the effect of disabling race detection for this section of code.
+ */
+#define QEMU_TSAN_ANNOTATE_IGNORE_READS_BEGIN() \
+    AnnotateIgnoreReadsBegin(__FILE__, __LINE__)
+#define QEMU_TSAN_ANNOTATE_IGNORE_READS_END() \
+    AnnotateIgnoreReadsEnd(__FILE__, __LINE__)
+/*
+ * Allows defining a region of code on which TSan will not record memory
+ * WRITES.  This has the effect of disabling race detection for this
+ * section of code.
+ */
+#define QEMU_TSAN_ANNOTATE_IGNORE_WRITES_BEGIN() \
+    AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
+#define QEMU_TSAN_ANNOTATE_IGNORE_WRITES_END() \
+    AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
+#else
+#define QEMU_TSAN_ANNOTATE_HAPPENS_BEFORE(addr)
+#define QEMU_TSAN_ANNOTATE_HAPPENS_AFTER(addr)
+#define QEMU_TSAN_ANNOTATE_THREAD_NAME(name)
+#define QEMU_TSAN_ANNOTATE_IGNORE_READS_BEGIN()
+#define QEMU_TSAN_ANNOTATE_IGNORE_READS_END()
+#define QEMU_TSAN_ANNOTATE_IGNORE_WRITES_BEGIN()
+#define QEMU_TSAN_ANNOTATE_IGNORE_WRITES_END()
+#endif
+
+void AnnotateHappensBefore(const char *f, int l, void *addr);
+void AnnotateHappensAfter(const char *f, int l, void *addr);
+void AnnotateThreadName(const char *f, int l, char *name);
+void AnnotateIgnoreReadsBegin(const char *f, int l);
+void AnnotateIgnoreReadsEnd(const char *f, int l);
+void AnnotateIgnoreWritesBegin(const char *f, int l);
+void AnnotateIgnoreWritesEnd(const char *f, int l);
+#endif
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index 380014ed80..e63450a893 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -819,6 +819,7 @@ void tcg_pool_reset(TCGContext *s);
 TranslationBlock *tcg_tb_alloc(TCGContext *s);
 
 void tcg_region_init(void);
+void tb_destroy(TranslationBlock *tb);
 void tcg_region_reset_all(void);
 
 size_t tcg_code_size(void);
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 1aa6cb47f2..1362bc6101 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -502,6 +502,14 @@ size_t tcg_nb_tbs(void)
     return nb_tbs;
 }
 
+static gboolean tcg_region_tree_traverse(gpointer k, gpointer v, gpointer data)
+{
+    TranslationBlock *tb = v;
+
+    tb_destroy(tb);
+    return FALSE;
+}
+
 static void tcg_region_tree_reset_all(void)
 {
     size_t i;
@@ -510,6 +518,7 @@ static void tcg_region_tree_reset_all(void)
     for (i = 0; i < region.n; i++) {
         struct tcg_region_tree *rt = region_trees + i * tree_size;
 
+        g_tree_foreach(rt->tree, tcg_region_tree_traverse, NULL);
         /* Increment the refcount first so that destroy acts as a reset */
         g_tree_ref(rt->tree);
         g_tree_destroy(rt->tree);
diff --git a/tests/Makefile.include b/tests/Makefile.include
index 5607c7290d..3f4448a20b 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -55,7 +55,6 @@ SYSEMU_TARGET_LIST := $(subst -softmmu.mak,,$(notdir \
 
 check-unit-y += tests/check-qdict$(EXESUF)
 check-unit-y += tests/check-block-qdict$(EXESUF)
-check-unit-$(CONFIG_SOFTMMU) += tests/test-char$(EXESUF)
 check-unit-y += tests/check-qnum$(EXESUF)
 check-unit-y += tests/check-qstring$(EXESUF)
 check-unit-y += tests/check-qlist$(EXESUF)
@@ -108,7 +107,6 @@ check-unit-y += tests/test-qht$(EXESUF)
 check-unit-y += tests/test-qht-par$(EXESUF)
 check-unit-y += tests/test-bitops$(EXESUF)
 check-unit-y += tests/test-bitcnt$(EXESUF)
-check-unit-$(CONFIG_SOFTMMU) += tests/test-qdev-global-props$(EXESUF)
 check-unit-y += tests/check-qom-interface$(EXESUF)
 check-unit-y += tests/check-qom-proplist$(EXESUF)
 check-unit-y += tests/test-qemu-opts$(EXESUF)
@@ -123,9 +121,16 @@ check-speed-$(CONFIG_BLOCK) += tests/benchmark-crypto-cipher$(EXESUF)
 check-unit-$(CONFIG_BLOCK) += tests/test-crypto-secret$(EXESUF)
 check-unit-$(call land,$(CONFIG_BLOCK),$(CONFIG_GNUTLS)) += tests/test-crypto-tlscredsx509$(EXESUF)
 check-unit-$(call land,$(CONFIG_BLOCK),$(CONFIG_GNUTLS)) += tests/test-crypto-tlssession$(EXESUF)
+ifndef CONFIG_TSAN
+# Some tests: test-char, test-qdev-global-props, and test-qga,
+# are not runnable under TSan due to a known issue.
+# https://github.com/google/sanitizers/issues/1116
+check-unit-$(CONFIG_SOFTMMU) += tests/test-char$(EXESUF)
+check-unit-$(CONFIG_SOFTMMU) += tests/test-qdev-global-props$(EXESUF)
 ifneq (,$(findstring qemu-ga,$(TOOLS)))
 check-unit-$(call land,$(CONFIG_LINUX),$(CONFIG_VIRTIO_SERIAL)) += tests/test-qga$(EXESUF)
 endif
+endif
 check-unit-$(CONFIG_SOFTMMU) += tests/test-timed-average$(EXESUF)
 check-unit-$(call land,$(CONFIG_SOFTMMU),$(CONFIG_INOTIFY1)) += tests/test-util-filemonitor$(EXESUF)
 check-unit-$(CONFIG_SOFTMMU) += tests/test-util-sockets$(EXESUF)
diff --git a/tests/docker/dockerfiles/fedora.docker b/tests/docker/dockerfiles/fedora.docker
index 92b6e11c8a..798ddd2c3e 100644
--- a/tests/docker/dockerfiles/fedora.docker
+++ b/tests/docker/dockerfiles/fedora.docker
@@ -1,4 +1,4 @@
-FROM fedora:30
+FROM fedora:32
 
 # Please keep this list sorted alphabetically
 ENV PACKAGES \
diff --git a/tests/docker/dockerfiles/ubuntu2004.docker b/tests/docker/dockerfiles/ubuntu2004.docker
new file mode 100644
index 0000000000..6050ce7e8a
--- /dev/null
+++ b/tests/docker/dockerfiles/ubuntu2004.docker
@@ -0,0 +1,65 @@
+FROM ubuntu:20.04
+ENV PACKAGES flex bison \
+    ccache \
+    clang-10\
+    gcc \
+    gettext \
+    git \
+    glusterfs-common \
+    libaio-dev \
+    libattr1-dev \
+    libbrlapi-dev \
+    libbz2-dev \
+    libcacard-dev \
+    libcap-ng-dev \
+    libcurl4-gnutls-dev \
+    libdrm-dev \
+    libepoxy-dev \
+    libfdt-dev \
+    libgbm-dev \
+    libgtk-3-dev \
+    libibverbs-dev \
+    libiscsi-dev \
+    libjemalloc-dev \
+    libjpeg-turbo8-dev \
+    liblzo2-dev \
+    libncurses5-dev \
+    libncursesw5-dev \
+    libnfs-dev \
+    libnss3-dev \
+    libnuma-dev \
+    libpixman-1-dev \
+    librados-dev \
+    librbd-dev \
+    librdmacm-dev \
+    libsasl2-dev \
+    libsdl2-dev \
+    libseccomp-dev \
+    libsnappy-dev \
+    libspice-protocol-dev \
+    libspice-server-dev \
+    libssh-dev \
+    libusb-1.0-0-dev \
+    libusbredirhost-dev \
+    libvdeplug-dev \
+    libvte-2.91-dev \
+    libxen-dev \
+    libzstd-dev \
+    make \
+    python3-yaml \
+    python3-sphinx \
+    sparse \
+    texinfo \
+    xfslibs-dev\
+    vim
+RUN apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get -y install $PACKAGES
+RUN dpkg -l $PACKAGES | sort > /packages.txt
+ENV FEATURES clang tsan pyyaml sdl2
+
+# https://bugs.launchpad.net/qemu/+bug/1838763
+ENV QEMU_CONFIGURE_OPTS --disable-libssh
+
+# Apply patch https://reviews.llvm.org/D75820
+# This is required for TSan in clang-10 to compile with QEMU.
+RUN sed -i 's/^const/static const/g' /usr/lib/llvm-10/lib/clang/10.0.0/include/sanitizer/tsan_interface.h
diff --git a/tests/docker/test-tsan b/tests/docker/test-tsan
new file mode 100755
index 0000000000..eb40ac45b7
--- /dev/null
+++ b/tests/docker/test-tsan
@@ -0,0 +1,44 @@
+#!/bin/bash -e
+#
+# This test will use TSan as part of a build and a make check.
+#
+# Copyright (c) 2020 Linaro
+# Copyright (c) 2016 Red Hat Inc.
+#
+# Authors:
+#  Robert Foley <robert.foley@linaro.org>
+#  Originally based on test-quick from Fam Zheng <famz@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2
+# or (at your option) any later version. See the COPYING file in
+# the top-level directory.
+
+. common.rc
+
+setup_tsan()
+{
+    requires clang tsan
+    tsan_log_dir="/tmp/qemu-test/build/tsan"
+    mkdir -p $tsan_log_dir > /dev/null || true
+    EXTRA_CONFIGURE_OPTS="${EXTRA_CONFIGURE_OPTS} --enable-tsan \
+                          --cc=clang-10 --cxx=clang++-10 \
+                          --disable-werror --extra-cflags=-O0"
+    # detect deadlocks is false currently simply because
+    # TSan crashes immediately with deadlock detector enabled.
+    # We have maxed out the history size to get the best chance of finding
+    # warnings during testing.
+    # Note, to get TSan to fail on warning, use exitcode=66 below.
+    tsan_opts="suppressions=/tmp/qemu-test/src/tests/tsan/suppressions.tsan\
+               detect_deadlocks=false history_size=7\
+               halt_on_error=0 exitcode=0 verbose=5\
+               log_path=$tsan_log_dir/tsan_warning"
+    export TSAN_OPTIONS="$tsan_opts"
+}
+
+cd "$BUILD_DIR"
+
+TARGET_LIST=${TARGET_LIST:-$DEF_TARGET_LIST} \
+setup_tsan
+build_qemu
+check_qemu
+install_qemu
diff --git a/tests/plugin/Makefile b/tests/plugin/Makefile
index 75467b6db8..b3250e2504 100644
--- a/tests/plugin/Makefile
+++ b/tests/plugin/Makefile
@@ -13,6 +13,7 @@ NAMES += mem
 NAMES += hotblocks
 NAMES += howvec
 NAMES += hotpages
+NAMES += lockstep
 
 SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES)))
 
diff --git a/tests/plugin/lockstep.c b/tests/plugin/lockstep.c
new file mode 100644
index 0000000000..a696673dff
--- /dev/null
+++ b/tests/plugin/lockstep.c
@@ -0,0 +1,340 @@
+/*
+ * Lockstep Execution Plugin
+ *
+ * Allows you to execute two QEMU instances in lockstep and report
+ * when their execution diverges. This is mainly useful for developers
+ * who want to see where a change to TCG code generation has
+ * introduced a subtle and hard to find bug.
+ *
+ * Caveats:
+ *   - single-threaded linux-user apps only with non-deterministic syscalls
+ *   - no MTTCG enabled system emulation (icount may help)
+ *
+ * While icount makes things more deterministic it doesn't mean a
+ * particular run may execute the exact same sequence of blocks. An
+ * asynchronous event (for example X11 graphics update) may cause a
+ * block to end early and a new partial block to start. This means
+ * serial only test cases are a better bet. -d nochain may also help.
+ *
+ * This code is not thread safe!
+ *
+ * Copyright (c) 2020 Linaro Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <glib.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <qemu-plugin.h>
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
+
+/* saved so we can uninstall later */
+static qemu_plugin_id_t our_id;
+
+static unsigned long bb_count;
+static unsigned long insn_count;
+
+/* Information about a translated block */
+typedef struct {
+    uint64_t pc;
+    uint64_t insns;
+} BlockInfo;
+
+/* Information about an execution state in the log */
+typedef struct {
+    BlockInfo *block;
+    unsigned long insn_count;
+    unsigned long block_count;
+} ExecInfo;
+
+/* The execution state we compare */
+typedef struct {
+    uint64_t pc;
+    unsigned long insn_count;
+} ExecState;
+
+typedef struct {
+    GSList *log_pos;
+    int distance;
+} DivergeState;
+
+/* list of translated block info */
+static GSList *blocks;
+
+/* execution log and points of divergence */
+static GSList *log, *divergence_log;
+
+static int socket_fd;
+static char *path_to_unlink;
+
+static bool verbose;
+
+static void plugin_cleanup(qemu_plugin_id_t id)
+{
+    /* Free our block data */
+    g_slist_free_full(blocks, &g_free);
+    g_slist_free_full(log, &g_free);
+    g_slist_free(divergence_log);
+
+    close(socket_fd);
+    if (path_to_unlink) {
+        unlink(path_to_unlink);
+    }
+}
+
+static void plugin_exit(qemu_plugin_id_t id, void *p)
+{
+    g_autoptr(GString) out = g_string_new("No divergence :-)\n");
+    g_string_append_printf(out, "Executed %ld/%d blocks\n",
+                           bb_count, g_slist_length(log));
+    g_string_append_printf(out, "Executed ~%ld instructions\n", insn_count);
+    qemu_plugin_outs(out->str);
+
+    plugin_cleanup(id);
+}
+
+static void report_divergance(ExecState *us, ExecState *them)
+{
+    DivergeState divrec = { log, 0 };
+    g_autoptr(GString) out = g_string_new("");
+    bool diverged = false;
+
+    /*
+     * If we have diverged before did we get back on track or are we
+     * totally loosing it?
+     */
+    if (divergence_log) {
+        DivergeState *last = (DivergeState *) divergence_log->data;
+        GSList *entry;
+
+        for (entry = log; g_slist_next(entry); entry = g_slist_next(entry)) {
+            if (entry == last->log_pos) {
+                break;
+            }
+            divrec.distance++;
+        }
+
+        /*
+         * If the last two records are so close it is likely we will
+         * not recover synchronisation with the other end.
+         */
+        if (divrec.distance == 1 && last->distance == 1) {
+            diverged = true;
+        }
+    }
+    divergence_log = g_slist_prepend(divergence_log,
+                                     g_memdup(&divrec, sizeof(divrec)));
+
+    /* Output short log entry of going out of sync... */
+    if (verbose || divrec.distance == 1 || diverged) {
+        g_string_printf(out, "@ %#016lx vs %#016lx (%d/%d since last)\n",
+                        us->pc, them->pc, g_slist_length(divergence_log),
+                        divrec.distance);
+        qemu_plugin_outs(out->str);
+    }
+
+    if (diverged) {
+        int i;
+        GSList *entry;
+
+        g_string_printf(out, "Δ insn_count @ %#016lx (%ld) vs %#016lx (%ld)\n",
+                        us->pc, us->insn_count, them->pc, them->insn_count);
+
+        for (entry = log, i = 0;
+             g_slist_next(entry) && i < 5;
+             entry = g_slist_next(entry), i++) {
+            ExecInfo *prev = (ExecInfo *) entry->data;
+            g_string_append_printf(out,
+                                   "  previously @ %#016lx/%ld (%ld insns)\n",
+                                   prev->block->pc, prev->block->insns,
+                                   prev->insn_count);
+        }
+        qemu_plugin_outs(out->str);
+        qemu_plugin_outs("too much divergence... giving up.");
+        qemu_plugin_uninstall(our_id, plugin_cleanup);
+    }
+}
+
+static void vcpu_tb_exec(unsigned int cpu_index, void *udata)
+{
+    BlockInfo *bi = (BlockInfo *) udata;
+    ExecState us, them;
+    ssize_t bytes;
+    ExecInfo *exec;
+
+    us.pc = bi->pc;
+    us.insn_count = insn_count;
+
+    /*
+     * Write our current position to the other end. If we fail the
+     * other end has probably died and we should shut down gracefully.
+     */
+    bytes = write(socket_fd, &us, sizeof(ExecState));
+    if (bytes < sizeof(ExecState)) {
+        qemu_plugin_outs(bytes < 0 ?
+                         "problem writing to socket" :
+                         "wrote less than expected to socket");
+        qemu_plugin_uninstall(our_id, plugin_cleanup);
+        return;
+    }
+
+    /*
+     * Now read where our peer has reached. Again a failure probably
+     * indicates the other end died and we should close down cleanly.
+     */
+    bytes = read(socket_fd, &them, sizeof(ExecState));
+    if (bytes < sizeof(ExecState)) {
+        qemu_plugin_outs(bytes < 0 ?
+                         "problem reading from socket" :
+                         "read less than expected");
+        qemu_plugin_uninstall(our_id, plugin_cleanup);
+        return;
+    }
+
+    /*
+     * Compare and report if we have diverged.
+     */
+    if (us.pc != them.pc) {
+        report_divergance(&us, &them);
+    }
+
+    /*
+     * Assume this block will execute fully and record it
+     * in the execution log.
+     */
+    insn_count += bi->insns;
+    bb_count++;
+    exec = g_new0(ExecInfo, 1);
+    exec->block = bi;
+    exec->insn_count = insn_count;
+    exec->block_count = bb_count;
+    log = g_slist_prepend(log, exec);
+}
+
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+    BlockInfo *bi = g_new0(BlockInfo, 1);
+    bi->pc = qemu_plugin_tb_vaddr(tb);
+    bi->insns = qemu_plugin_tb_n_insns(tb);
+
+    /* save a reference so we can free later */
+    blocks = g_slist_prepend(blocks, bi);
+    qemu_plugin_register_vcpu_tb_exec_cb(tb, vcpu_tb_exec,
+                                         QEMU_PLUGIN_CB_NO_REGS, (void *)bi);
+}
+
+
+/*
+ * Instead of encoding master/slave status into what is essentially
+ * two peers we shall just take the simple approach of checking for
+ * the existence of the pipe and assuming if it's not there we are the
+ * first process.
+ */
+static bool setup_socket(const char *path)
+{
+    struct sockaddr_un sockaddr;
+    int fd;
+
+    fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (fd < 0) {
+        perror("create socket");
+        return false;
+    }
+
+    sockaddr.sun_family = AF_UNIX;
+    g_strlcpy(sockaddr.sun_path, path, sizeof(sockaddr.sun_path) - 1);
+    if (bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) {
+        perror("bind socket");
+        close(fd);
+        return false;
+    }
+
+    /* remember to clean-up */
+    path_to_unlink = g_strdup(path);
+
+    if (listen(fd, 1) < 0) {
+        perror("listen socket");
+        close(fd);
+        return false;
+    }
+
+    socket_fd = accept(fd, NULL, NULL);
+    if (socket_fd < 0 && errno != EINTR) {
+        perror("accept socket");
+        return false;
+    }
+
+    qemu_plugin_outs("setup_socket::ready\n");
+
+    return true;
+}
+
+static bool connect_socket(const char *path)
+{
+    int fd;
+    struct sockaddr_un sockaddr;
+
+    fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (fd < 0) {
+        perror("create socket");
+        return false;
+    }
+
+    sockaddr.sun_family = AF_UNIX;
+    g_strlcpy(sockaddr.sun_path, path, sizeof(sockaddr.sun_path) - 1);
+
+    if (connect(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) {
+        perror("failed to connect");
+        return false;
+    }
+
+    qemu_plugin_outs("connect_socket::ready\n");
+
+    socket_fd = fd;
+    return true;
+}
+
+static bool setup_unix_socket(const char *path)
+{
+    if (g_file_test(path, G_FILE_TEST_EXISTS)) {
+        return connect_socket(path);
+    } else {
+        return setup_socket(path);
+    }
+}
+
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+                                           const qemu_info_t *info,
+                                           int argc, char **argv)
+{
+    int i;
+
+    if (!argc || !argv[0]) {
+        qemu_plugin_outs("Need a socket path to talk to other instance.");
+        return -1;
+    }
+
+    for (i = 0; i < argc; i++) {
+        char *p = argv[i];
+        if (strcmp(p, "verbose") == 0) {
+            verbose = true;
+        } else if (!setup_unix_socket(argv[0])) {
+            qemu_plugin_outs("Failed to setup socket for communications.");
+            return -1;
+        }
+    }
+
+    our_id = id;
+
+    qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+    qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
+    return 0;
+}
diff --git a/tests/qtest/Makefile.include b/tests/qtest/Makefile.include
index 5023fa413d..98af2c2d93 100644
--- a/tests/qtest/Makefile.include
+++ b/tests/qtest/Makefile.include
@@ -314,12 +314,15 @@ tests/qtest/tpm-tis-device-test$(EXESUF): tests/qtest/tpm-tis-device-test.o test
 # QTest rules
 
 TARGETS=$(patsubst %-softmmu,%, $(filter %-softmmu,$(TARGET_DIRS)))
+QTEST_TARGETS =
+# The qtests are not runnable (yet) under TSan due to a known issue.
+# https://github.com/google/sanitizers/issues/1116
+ifndef CONFIG_TSAN
 ifeq ($(CONFIG_POSIX),y)
 QTEST_TARGETS = $(TARGETS)
 check-qtest-y=$(foreach TARGET,$(TARGETS), $(check-qtest-$(TARGET)-y:%=tests/qtest/%$(EXESUF)))
 check-qtest-y += $(check-qtest-generic-y:%=tests/qtest/%$(EXESUF))
-else
-QTEST_TARGETS =
+endif
 endif
 
 qtest-obj-y = tests/qtest/libqtest.o $(test-util-obj-y)
diff --git a/tests/tcg/Makefile.target b/tests/tcg/Makefile.target
index b3cff3cad1..4b2b696fce 100644
--- a/tests/tcg/Makefile.target
+++ b/tests/tcg/Makefile.target
@@ -126,9 +126,11 @@ RUN_TESTS=$(patsubst %,run-%, $(TESTS))
 
 # If plugins exist also include those in the tests
 ifeq ($(CONFIG_PLUGIN),y)
-PLUGIN_DIR=../../plugin
-VPATH+=$(PLUGIN_DIR)
-PLUGINS=$(notdir $(wildcard $(PLUGIN_DIR)/*.so))
+PLUGIN_SRC=$(SRC_PATH)/tests/plugin
+PLUGIN_LIB=../../plugin
+VPATH+=$(PLUGIN_LIB)
+PLUGINS=$(filter-out liblockstep.so,\
+		$(patsubst %.c, lib%.so, $(notdir $(wildcard $(PLUGIN_SRC)/*.c))))
 
 # We need to ensure expand the run-plugin-TEST-with-PLUGIN
 # pre-requistes manually here as we can't use stems to handle it. We
@@ -152,7 +154,7 @@ run-%: %
 
 run-plugin-%:
 	$(call run-test, $@, $(QEMU) $(QEMU_OPTS) \
-		-plugin $(PLUGIN_DIR)/$(call extract-plugin,$@) \
+		-plugin $(PLUGIN_LIB)/$(call extract-plugin,$@) \
 		-d plugin -D $*.pout \
 		 $(call strip-plugin,$<), \
 	"$* on $(TARGET_NAME)")
@@ -168,7 +170,7 @@ run-plugin-%:
 	$(call run-test, $@, \
 	  $(QEMU) -monitor none -display none \
 		  -chardev file$(COMMA)path=$@.out$(COMMA)id=output \
-	   	  -plugin $(PLUGIN_DIR)/$(call extract-plugin,$@) \
+	   	  -plugin $(PLUGIN_LIB)/$(call extract-plugin,$@) \
 	    	  -d plugin -D $*.pout \
 	   	  $(QEMU_OPTS) $(call strip-plugin,$<), \
 	  "$* on $(TARGET_NAME)")
diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
index 312f36cde5..b617f2ac7e 100644
--- a/tests/tcg/aarch64/Makefile.target
+++ b/tests/tcg/aarch64/Makefile.target
@@ -20,8 +20,9 @@ run-fcvt: fcvt
 # Pauth Tests
 ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_3),)
 AARCH64_TESTS += pauth-1 pauth-2 pauth-4
-run-pauth-%: QEMU_OPTS += -cpu max
 pauth-%: CFLAGS += -march=armv8.3-a
+run-pauth-%: QEMU_OPTS += -cpu max
+run-plugin-pauth-%: QEMU_OPTS += -cpu max
 endif
 
 # Semihosting smoke test for linux-user
@@ -31,7 +32,7 @@ run-semihosting: semihosting
 
 run-plugin-semihosting-with-%:
 	$(call run-test, $@, $(QEMU) $(QEMU_OPTS) \
-		-plugin $(PLUGIN_DIR)/$(call extract-plugin,$@) \
+		-plugin $(PLUGIN_LIB)/$(call extract-plugin,$@) \
 		 $(call strip-plugin,$<) 2> $<.err, \
 		"$< on $(TARGET_NAME) with $*")
 
diff --git a/tests/tcg/arm/Makefile.target b/tests/tcg/arm/Makefile.target
index 3da09a38be..ec95156562 100644
--- a/tests/tcg/arm/Makefile.target
+++ b/tests/tcg/arm/Makefile.target
@@ -45,7 +45,7 @@ run-semihosting-arm: semihosting-arm
 
 run-plugin-semihosting-with-%:
 	$(call run-test, $@, $(QEMU) $(QEMU_OPTS) \
-		-plugin $(PLUGIN_DIR)/$(call extract-plugin,$@) \
+		-plugin $(PLUGIN_LIB)/$(call extract-plugin,$@) \
 		 $(call strip-plugin,$<) 2> $<.err, \
 		"$< on $(TARGET_NAME) with $*")
 
diff --git a/tests/tcg/i386/Makefile.target b/tests/tcg/i386/Makefile.target
index 53efec0668..1a6463a7dc 100644
--- a/tests/tcg/i386/Makefile.target
+++ b/tests/tcg/i386/Makefile.target
@@ -12,6 +12,7 @@ X86_64_TESTS:=$(filter test-i386-ssse3, $(ALL_X86_TESTS))
 
 test-i386-pcmpistri: CFLAGS += -msse4.2
 run-test-i386-pcmpistri: QEMU_OPTS += -cpu max
+run-plugin-test-i386-pcmpistri-%: QEMU_OPTS += -cpu max
 
 #
 # hello-i386 is a barebones app
diff --git a/tests/tsan/blacklist.tsan b/tests/tsan/blacklist.tsan
new file mode 100644
index 0000000000..75e444f5dc
--- /dev/null
+++ b/tests/tsan/blacklist.tsan
@@ -0,0 +1,10 @@
+# This is an example blacklist.
+# To enable use of the blacklist add this to configure:
+# "--extra-cflags=-fsanitize-blacklist=<src path>/tests/tsan/blacklist.tsan"
+# The eventual goal would be to fix these warnings.
+
+# TSan is not happy about setting/getting of dirty bits,
+# for example, cpu_physical_memory_set_dirty_range,
+# and cpu_physical_memory_get_dirty.
+src:bitops.c
+src:bitmap.c
diff --git a/tests/tsan/suppressions.tsan b/tests/tsan/suppressions.tsan
new file mode 100644
index 0000000000..73414b9ebd
--- /dev/null
+++ b/tests/tsan/suppressions.tsan
@@ -0,0 +1,14 @@
+# This is the set of runtime suppressions of TSan warnings.
+# The goal would be to have here only items we do not
+# plan to fix, and to explain why for each item.
+
+# TSan reports a double lock on RECURSIVE mutexes.
+# Since the recursive lock is intentional, we choose to ignore it.
+mutex:aio_context_acquire
+mutex:pthread_mutex_lock
+
+# TSan reports a race betwen pthread_mutex_init() and
+# pthread_mutex_lock().  Since this is outside of QEMU,
+# we choose to ignore it.
+race:pthread_mutex_init
+race:pthread_mutex_lock
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index bd593e61bc..613f4c118e 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -37,12 +37,19 @@
 #endif
 #endif
 
+#ifdef CONFIG_TSAN
+#include <sanitizer/tsan_interface.h>
+#endif
+
 typedef struct {
     Coroutine base;
     void *stack;
     size_t stack_size;
     sigjmp_buf env;
 
+    void *tsan_co_fiber;
+    void *tsan_caller_fiber;
+
 #ifdef CONFIG_VALGRIND_H
     unsigned int valgrind_stack_id;
 #endif
@@ -65,7 +72,18 @@ union cc_arg {
     int i[2];
 };
 
-static void finish_switch_fiber(void *fake_stack_save)
+/* QEMU_ALWAYS_INLINE only does so if __OPTIMIZE__, so we cannot use it. */
+static inline __attribute__((always_inline))
+void on_new_fiber(CoroutineUContext *co)
+{
+#ifdef CONFIG_TSAN
+    co->tsan_co_fiber = __tsan_create_fiber(0); /* flags: sync on switch */
+    co->tsan_caller_fiber = __tsan_get_current_fiber();
+#endif
+}
+
+static inline __attribute__((always_inline))
+void finish_switch_fiber(void *fake_stack_save)
 {
 #ifdef CONFIG_ASAN
     const void *bottom_old;
@@ -78,13 +96,30 @@ static void finish_switch_fiber(void *fake_stack_save)
         leader.stack_size = size_old;
     }
 #endif
+#ifdef CONFIG_TSAN
+    if (fake_stack_save) {
+        __tsan_release(fake_stack_save);
+        __tsan_switch_to_fiber(fake_stack_save, 0);  /* 0=synchronize */
+    }
+#endif
 }
 
-static void start_switch_fiber(void **fake_stack_save,
-                               const void *bottom, size_t size)
+static inline __attribute__((always_inline)) void start_switch_fiber(
+    CoroutineAction action, void **fake_stack_save,
+    const void *bottom, size_t size, void *new_fiber)
 {
 #ifdef CONFIG_ASAN
-    __sanitizer_start_switch_fiber(fake_stack_save, bottom, size);
+    __sanitizer_start_switch_fiber(
+            action == COROUTINE_TERMINATE ? NULL : fake_stack_save,
+            bottom, size);
+#endif
+#ifdef CONFIG_TSAN
+    void *curr_fiber =
+        __tsan_get_current_fiber();
+    __tsan_acquire(curr_fiber);
+
+    *fake_stack_save = curr_fiber;
+    __tsan_switch_to_fiber(new_fiber, 0);  /* 0=synchronize */
 #endif
 }
 
@@ -104,8 +139,12 @@ static void coroutine_trampoline(int i0, int i1)
 
     /* Initialize longjmp environment and switch back the caller */
     if (!sigsetjmp(self->env, 0)) {
-        start_switch_fiber(&fake_stack_save,
-                           leader.stack, leader.stack_size);
+        start_switch_fiber(
+            COROUTINE_YIELD,
+            &fake_stack_save,
+            leader.stack,
+            leader.stack_size,
+            self->tsan_caller_fiber);
         siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
     }
 
@@ -154,12 +193,16 @@ Coroutine *qemu_coroutine_new(void)
 
     arg.p = co;
 
+    on_new_fiber(co);
     makecontext(&uc, (void (*)(void))coroutine_trampoline,
                 2, arg.i[0], arg.i[1]);
 
     /* swapcontext() in, siglongjmp() back out */
     if (!sigsetjmp(old_env, 0)) {
-        start_switch_fiber(&fake_stack_save, co->stack, co->stack_size);
+        start_switch_fiber(
+            COROUTINE_YIELD,
+            &fake_stack_save,
+            co->stack, co->stack_size, co->tsan_co_fiber);
         swapcontext(&old_uc, &uc);
     }
 
@@ -216,8 +259,8 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
 
     ret = sigsetjmp(from->env, 0);
     if (ret == 0) {
-        start_switch_fiber(action == COROUTINE_TERMINATE ?
-                           NULL : &fake_stack_save, to->stack, to->stack_size);
+        start_switch_fiber(action, &fake_stack_save,
+                           to->stack, to->stack_size, to->tsan_co_fiber);
         siglongjmp(to->env, action);
     }
 
@@ -231,6 +274,11 @@ Coroutine *qemu_coroutine_self(void)
     if (!current) {
         current = &leader.base;
     }
+#ifdef CONFIG_TSAN
+    if (!leader.tsan_co_fiber) {
+        leader.tsan_co_fiber = __tsan_get_current_fiber();
+    }
+#endif
     return current;
 }
 
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 838980aaa5..b4c2359272 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -15,6 +15,7 @@
 #include "qemu/atomic.h"
 #include "qemu/notify.h"
 #include "qemu-thread-common.h"
+#include "qemu/tsan.h"
 
 static bool name_threads;
 
@@ -513,6 +514,7 @@ static void *qemu_thread_start(void *args)
 # endif
     }
 #endif
+    QEMU_TSAN_ANNOTATE_THREAD_NAME(qemu_thread_args->name);
     g_free(qemu_thread_args->name);
     g_free(qemu_thread_args);
     pthread_cleanup_push(qemu_thread_atexit_notify, NULL);
diff --git a/util/qht.c b/util/qht.c
index aa51be3c52..67e5d5b916 100644
--- a/util/qht.c
+++ b/util/qht.c
@@ -348,6 +348,7 @@ static inline void qht_chain_destroy(const struct qht_bucket *head)
     struct qht_bucket *curr = head->next;
     struct qht_bucket *prev;
 
+    qemu_spin_destroy(&head->lock);
     while (curr) {
         prev = curr;
         curr = curr->next;