diff --git a/.cirrus.yml b/.cirrus.yml
index 27efc48619..90645fede6 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -22,7 +22,9 @@ macos_task:
   install_script:
     - brew install pkg-config python gnu-sed glib pixman make sdl2
   script:
-    - ./configure --python=/usr/local/bin/python3 || { cat config.log; exit 1; }
+    - mkdir build
+    - 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)
 
@@ -33,6 +35,8 @@ macos_xcode_task:
   install_script:
     - brew install pkg-config gnu-sed glib pixman make sdl2
   script:
-    - ./configure --cc=clang || { cat config.log; exit 1; }
+    - mkdir build
+    - cd build
+    - ../configure --cc=clang || { cat config.log; exit 1; }
     - gmake -j$(sysctl -n hw.ncpu)
     - gmake check -j$(sysctl -n hw.ncpu)
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e3db1b847c..ebcef0ebe9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,7 +6,9 @@ build-system1:
  script:
  - apt-get install -y -qq libgtk-3-dev libvte-dev nettle-dev libcacard-dev
       libusb-dev libvde-dev libspice-protocol-dev libgl1-mesa-dev libvdeplug-dev
- - ./configure --enable-werror --target-list="aarch64-softmmu alpha-softmmu
+ - mkdir build
+ - cd build
+ - ../configure --enable-werror --target-list="aarch64-softmmu alpha-softmmu
       cris-softmmu hppa-softmmu lm32-softmmu moxie-softmmu microblazeel-softmmu
       mips64el-softmmu m68k-softmmu ppc-softmmu riscv64-softmmu sparc-softmmu"
  - make -j2
@@ -16,7 +18,9 @@ build-system2:
  script:
  - apt-get install -y -qq libsdl2-dev libgcrypt-dev libbrlapi-dev libaio-dev
       libfdt-dev liblzo2-dev librdmacm-dev libibverbs-dev libibumad-dev
- - ./configure --enable-werror --target-list="tricore-softmmu unicore32-softmmu
+ - mkdir build
+ - cd build
+ - ../configure --enable-werror --target-list="tricore-softmmu unicore32-softmmu
       microblaze-softmmu mips-softmmu riscv32-softmmu s390x-softmmu sh4-softmmu
       sparc64-softmmu x86_64-softmmu xtensa-softmmu nios2-softmmu or1k-softmmu"
  - make -j2
@@ -24,7 +28,9 @@ build-system2:
 
 build-disabled:
  script:
- - ./configure --enable-werror --disable-rdma --disable-slirp --disable-curl
+ - mkdir build
+ - cd build
+ - ../configure --enable-werror --disable-rdma --disable-slirp --disable-curl
       --disable-capstone --disable-live-block-migration --disable-glusterfs
       --disable-replication --disable-coroutine-pool --disable-smartcard
       --disable-guest-agent --disable-curses --disable-libxml2 --disable-tpm
@@ -37,7 +43,9 @@ build-disabled:
 build-tcg-disabled:
  script:
  - apt-get install -y -qq clang libgtk-3-dev libusb-dev
- - ./configure --cc=clang --enable-werror --disable-tcg --audio-drv-list=""
+ - mkdir build
+ - cd build
+ - ../configure --cc=clang --enable-werror --disable-tcg --audio-drv-list=""
  - make -j2
  - make check-unit
  - make check-qapi-schema
@@ -52,7 +60,9 @@ build-tcg-disabled:
 
 build-user:
  script:
- - ./configure --enable-werror --disable-system --disable-guest-agent
+ - mkdir build
+ - cd build
+ - ../configure --enable-werror --disable-system --disable-guest-agent
                --disable-capstone --disable-slirp --disable-fdt
  - make -j2
  - make run-tcg-tests-i386-linux-user run-tcg-tests-x86_64-linux-user
@@ -61,7 +71,9 @@ build-clang:
  script:
  - apt-get install -y -qq clang libsdl2-dev libattr1-dev libcap-ng-dev
       xfslibs-dev libiscsi-dev libnfs-dev libseccomp-dev gnutls-dev librbd-dev
- - ./configure --cc=clang --cxx=clang++ --enable-werror
+ - mkdir build
+ - cd build
+ - ../configure --cc=clang --cxx=clang++ --enable-werror
       --target-list="alpha-softmmu arm-softmmu m68k-softmmu mips64-softmmu
                      ppc-softmmu s390x-softmmu x86_64-softmmu arm-linux-user"
  - make -j2
@@ -70,7 +82,9 @@ build-clang:
 build-tci:
  script:
  - TARGETS="aarch64 alpha arm hppa m68k microblaze moxie ppc64 s390x x86_64"
- - ./configure --enable-tcg-interpreter
+ - mkdir build
+ - cd build
+ - ../configure --enable-tcg-interpreter
       --target-list="$(for tg in $TARGETS; do echo -n ${tg}'-softmmu '; done)"
  - make -j2
  - make tests/boot-serial-test tests/cdrom-test tests/pxe-test
diff --git a/.shippable.yml b/.shippable.yml
index f74a3de3ff..83aae08bb4 100644
--- a/.shippable.yml
+++ b/.shippable.yml
@@ -35,5 +35,7 @@ build:
     options: "-e HOME=/root"
   ci:
     - unset CC
-    - ./configure ${QEMU_CONFIGURE_OPTS} --target-list=${TARGET_LIST}
+    - mkdir build
+    - cd build
+    - ../configure ${QEMU_CONFIGURE_OPTS} --target-list=${TARGET_LIST}
     - make -j$(($(getconf _NPROCESSORS_ONLN) + 1))
diff --git a/.travis.yml b/.travis.yml
index 6cb8af6fa5..376b7d6dfa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -73,8 +73,8 @@ notifications:
 
 env:
   global:
-    - SRC_DIR="."
-    - BUILD_DIR="."
+    - SRC_DIR=".."
+    - BUILD_DIR="build"
     - BASE_CONFIG="--disable-docs --disable-tools"
     - TEST_CMD="make check V=1"
     # This is broadly a list of "mainline" softmmu targets which have support across the major distros
@@ -180,18 +180,13 @@ matrix:
       compiler: clang
 
 
-    - env:
-        - CONFIG="--disable-user --target-list=${MAIN_SOFTMMU_TARGETS}"
-        - CACHE_NAME="${TRAVIS_BRANCH}-linux-clang-default"
-      compiler: clang
-
-
     - env:
         - CONFIG="--target-list=${MAIN_SOFTMMU_TARGETS} "
         - CACHE_NAME="${TRAVIS_BRANCH}-linux-clang-sanitize"
       compiler: clang
       before_script:
-        - ./configure ${CONFIG} --extra-cflags="-fsanitize=undefined -Werror" || { cat config.log && exit 1; }
+        - mkdir -p ${BUILD_DIR} && cd ${BUILD_DIR}
+        - ${SRC_DIR}/configure ${CONFIG} --extra-cflags="-fsanitize=undefined -Werror" || { cat config.log && exit 1; }
 
 
     - env:
@@ -214,10 +209,11 @@ matrix:
         - TEST_CMD=""
 
 
-    # We manually include builds which we disable "make check" for
+    # Check the TCG interpreter (TCI)
     - env:
-        - CONFIG="--enable-debug --enable-tcg-interpreter"
-        - TEST_CMD=""
+        - CONFIG="--enable-debug-tcg --enable-tcg-interpreter --disable-kvm --disable-containers
+            --target-list=alpha-softmmu,arm-softmmu,hppa-softmmu,m68k-softmmu,microblaze-softmmu,moxie-softmmu,ppc-softmmu,s390x-softmmu,x86_64-softmmu"
+        - TEST_CMD="make check-qtest check-tcg V=1"
 
 
     # We don't need to exercise every backend with every front-end
@@ -322,7 +318,8 @@ matrix:
         - CONFIG="--cc=gcc-9 --cxx=g++-9 --disable-pie --disable-linux-user"
         - TEST_CMD=""
       before_script:
-        - ./configure ${CONFIG} --extra-cflags="-g3 -O0 -Wno-error=stringop-truncation -fsanitize=thread -fuse-ld=gold" || { cat config.log && exit 1; }
+        - mkdir -p ${BUILD_DIR} && cd ${BUILD_DIR}
+        - ${SRC_DIR}/configure ${CONFIG} --extra-cflags="-g3 -O0 -Wno-error=stringop-truncation -fsanitize=thread -fuse-ld=gold" || { cat config.log && exit 1; }
 
 
     # Run check-tcg against linux-user
@@ -353,6 +350,92 @@ matrix:
         - TEST_CMD="make -j3 check-tcg V=1"
         - CACHE_NAME="${TRAVIS_BRANCH}-linux-gcc-debug-tcg"
 
+    - arch: arm64
+      dist: xenial
+      addons:
+        apt_packages:
+          - libaio-dev
+          - libattr1-dev
+          - libbrlapi-dev
+          - libcap-ng-dev
+          - libgcrypt20-dev
+          - libgnutls28-dev
+          - libgtk-3-dev
+          - libiscsi-dev
+          - liblttng-ust-dev
+          - libncurses5-dev
+          - libnfs-dev
+          - libnss3-dev
+          - libpixman-1-dev
+          - libpng-dev
+          - librados-dev
+          - libsdl2-dev
+          - libseccomp-dev
+          - liburcu-dev
+          - libusb-1.0-0-dev
+          - libvdeplug-dev
+          - libvte-2.91-dev
+      env:
+        - TEST_CMD="make check check-tcg V=1"
+        - CONFIG="--disable-containers --target-list=${MAIN_SOFTMMU_TARGETS}"
+
+    - arch: ppc64le
+      dist: xenial
+      addons:
+        apt_packages:
+          - libaio-dev
+          - libattr1-dev
+          - libbrlapi-dev
+          - libcap-ng-dev
+          - libgcrypt20-dev
+          - libgnutls28-dev
+          - libgtk-3-dev
+          - libiscsi-dev
+          - liblttng-ust-dev
+          - libncurses5-dev
+          - libnfs-dev
+          - libnss3-dev
+          - libpixman-1-dev
+          - libpng-dev
+          - librados-dev
+          - libsdl2-dev
+          - libseccomp-dev
+          - liburcu-dev
+          - libusb-1.0-0-dev
+          - libvdeplug-dev
+          - libvte-2.91-dev
+      env:
+        - TEST_CMD="make check check-tcg V=1"
+        - CONFIG="--disable-containers --target-list=${MAIN_SOFTMMU_TARGETS},ppc64le-linux-user"
+
+    - arch: s390x
+      dist: bionic
+      addons:
+        apt_packages:
+          - libaio-dev
+          - libattr1-dev
+          - libbrlapi-dev
+          - libcap-ng-dev
+          - libgcrypt20-dev
+          - libgnutls28-dev
+          - libgtk-3-dev
+          - libiscsi-dev
+          - liblttng-ust-dev
+          - libncurses5-dev
+          - libnfs-dev
+          - libnss3-dev
+          - libpixman-1-dev
+          - libpng-dev
+          - librados-dev
+          - libsdl2-dev
+          - libseccomp-dev
+          - liburcu-dev
+          - libusb-1.0-0-dev
+          - libvdeplug-dev
+          - libvte-2.91-dev
+      env:
+        - TEST_CMD="make check check-tcg V=1"
+        - CONFIG="--disable-containers --target-list=${MAIN_SOFTMMU_TARGETS},s390x-linux-user"
 
     # Release builds
     # The make-release script expect a QEMU version, so our tag must start with a 'v'.
@@ -373,5 +456,6 @@ matrix:
         - make -C ${SRC_DIR} qemu-${QEMU_VERSION}.tar.bz2
         - ls -l ${SRC_DIR}/qemu-${QEMU_VERSION}.tar.bz2
         - tar -xf ${SRC_DIR}/qemu-${QEMU_VERSION}.tar.bz2 && cd qemu-${QEMU_VERSION}
-        - ./configure ${BASE_CONFIG} ${CONFIG} || { cat config.log && exit 1; }
+        - mkdir -p release-build && cd release-build
+        - ../configure ${BASE_CONFIG} ${CONFIG} || { cat config.log && exit 1; }
         - make install
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index c01f59c743..62068d10c3 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -156,7 +156,7 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
 #if defined(DEBUG_DISAS)
     if (qemu_loglevel_mask(CPU_LOG_TB_CPU)
         && qemu_log_in_addr_range(itb->pc)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         int flags = 0;
         if (qemu_loglevel_mask(CPU_LOG_TB_FPU)) {
             flags |= CPU_DUMP_FPU;
@@ -165,7 +165,7 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
         flags |= CPU_DUMP_CCOP;
 #endif
         log_cpu_state(cpu, flags);
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif /* DEBUG_DISAS */
 
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 9f48da9472..bb325a2bc4 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1804,7 +1804,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM) &&
         qemu_log_in_addr_range(tb->pc)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("OUT: [size=%d]\n", gen_code_size);
         if (tcg_ctx->data_gen_ptr) {
             size_t code_size = tcg_ctx->data_gen_ptr - tb->tc.ptr;
@@ -1829,7 +1829,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
         }
         qemu_log("\n");
         qemu_log_flush();
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 
diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index f977682be7..603d17ff83 100644
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -138,11 +138,11 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(db->pc_first)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("----------------\n");
         ops->disas_log(db, cpu);
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 }
diff --git a/bsd-user/main.c b/bsd-user/main.c
index 470a8bf79e..7f4e3cd627 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -963,7 +963,7 @@ int main(int argc, char **argv)
 
     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
         qemu_log("guest_base  0x%lx\n", guest_base);
-        log_page_dump();
+        log_page_dump("binary load");
 
         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
diff --git a/configure b/configure
index 5723a29070..940bf9e87a 100755
--- a/configure
+++ b/configure
@@ -302,6 +302,7 @@ audio_win_int=""
 libs_qga=""
 debug_info="yes"
 stack_protector=""
+use_containers="yes"
 
 if test -e "$source_path/.git"
 then
@@ -1535,6 +1536,10 @@ for opt do
   ;;
   --disable-plugins) plugins="no"
   ;;
+  --enable-containers) use_containers="yes"
+  ;;
+  --disable-containers) use_containers="no"
+  ;;
   *)
       echo "ERROR: unknown option $opt"
       echo "Try '$0 --help' for more information"
@@ -1718,6 +1723,7 @@ Advanced options (experts only):
                            track the maximum stack usage of stacks created by qemu_alloc_stack
   --enable-plugins
                            enable plugins via shared library loading
+  --disable-containers     don't use containers for cross-building
 
 Optional features, enabled with --enable-FEATURE and
 disabled with --disable-FEATURE, default is enabled if available:
@@ -6399,6 +6405,7 @@ else
 echo "local state directory   queried at runtime"
 echo "Windows SDK       $win_sdk"
 fi
+echo "Build directory   $(pwd)"
 echo "Source path       $source_path"
 echo "GIT binary        $git"
 echo "GIT submodules    $git_submodules"
@@ -7996,7 +8003,7 @@ done
 (for i in $cross_cc_vars; do
   export $i
 done
-export target_list source_path
+export target_list source_path use_containers
 $source_path/tests/tcg/configure.sh)
 
 # temporary config to build submodules
diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 27f286858a..ab5be0c729 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -418,13 +418,15 @@ access, so they SHOULD NOT be exposed to external interfaces if you are
 concerned about attackers taking control of the guest and potentially
 exploiting a QEMU security bug to compromise the host.
 
-QEMU binary
------------
+QEMU binaries
+-------------
 
 By default, qemu-system-x86_64 is searched in $PATH to run the guest. If there
 isn't one, or if it is older than 2.10, the test won't work. In this case,
 provide the QEMU binary in env var: ``QEMU=/path/to/qemu-2.10+``.
 
+Likewise the path to qemu-img can be set in QEMU_IMG environment variable.
+
 Make jobs
 ---------
 
diff --git a/exec.c b/exec.c
index efdc0aee98..d4b769d0d4 100644
--- a/exec.c
+++ b/exec.c
@@ -1225,13 +1225,13 @@ void cpu_abort(CPUState *cpu, const char *fmt, ...)
     fprintf(stderr, "\n");
     cpu_dump_state(cpu, stderr, CPU_DUMP_FPU | CPU_DUMP_CCOP);
     if (qemu_log_separate()) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("qemu: fatal: ");
         qemu_log_vprintf(fmt, ap2);
         qemu_log("\n");
         log_cpu_state(cpu, CPU_DUMP_FPU | CPU_DUMP_CCOP);
         qemu_log_flush();
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
         qemu_log_close();
     }
     va_end(ap2);
diff --git a/hw/net/can/can_sja1000.c b/hw/net/can/can_sja1000.c
index 1f81341554..39c78faf9b 100644
--- a/hw/net/can/can_sja1000.c
+++ b/hw/net/can/can_sja1000.c
@@ -247,8 +247,8 @@ int can_sja_accept_filter(CanSJA1000State *s,
 static void can_display_msg(const char *prefix, const qemu_can_frame *msg)
 {
     int i;
+    FILE *logfile = qemu_log_lock();
 
-    qemu_log_lock();
     qemu_log("%s%03X [%01d] %s %s",
              prefix,
              msg->can_id & QEMU_CAN_EFF_MASK,
@@ -261,7 +261,7 @@ static void can_display_msg(const char *prefix, const qemu_can_frame *msg)
     }
     qemu_log("\n");
     qemu_log_flush();
-    qemu_log_unlock();
+    qemu_log_unlock(logfile);
 }
 
 static void buff2frame_pel(const uint8_t *buff, qemu_can_frame *frame)
diff --git a/include/exec/log.h b/include/exec/log.h
index e2cfd436e6..fcc7b9e00b 100644
--- a/include/exec/log.h
+++ b/include/exec/log.h
@@ -15,8 +15,15 @@
  */
 static inline void log_cpu_state(CPUState *cpu, int flags)
 {
+    QemuLogFile *logfile;
+
     if (qemu_log_enabled()) {
-        cpu_dump_state(cpu, qemu_logfile, flags);
+        rcu_read_lock();
+        logfile = atomic_rcu_read(&qemu_logfile);
+        if (logfile) {
+            cpu_dump_state(cpu, logfile->fd, flags);
+        }
+        rcu_read_unlock();
     }
 }
 
@@ -40,19 +47,36 @@ static inline void log_cpu_state_mask(int mask, CPUState *cpu, int flags)
 static inline void log_target_disas(CPUState *cpu, target_ulong start,
                                     target_ulong len)
 {
-    target_disas(qemu_logfile, cpu, start, len);
+    QemuLogFile *logfile;
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
+        target_disas(logfile->fd, cpu, start, len);
+    }
+    rcu_read_unlock();
 }
 
 static inline void log_disas(void *code, unsigned long size)
 {
-    disas(qemu_logfile, code, size);
+    QemuLogFile *logfile;
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
+        disas(logfile->fd, code, size);
+    }
+    rcu_read_unlock();
 }
 
 #if defined(CONFIG_USER_ONLY)
 /* page_dump() output to the log file: */
-static inline void log_page_dump(void)
+static inline void log_page_dump(const char *operation)
 {
-    page_dump(qemu_logfile);
+    FILE *logfile = qemu_log_lock();
+    if (logfile) {
+        qemu_log("page layout changed following %s\n", operation);
+        page_dump(logfile);
+    }
+    qemu_log_unlock(logfile);
 }
 #endif
 #endif
diff --git a/include/qemu/log.h b/include/qemu/log.h
index a91105b2ad..e0f4e40628 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -3,9 +3,16 @@
 
 /* A small part of this API is split into its own header */
 #include "qemu/log-for-trace.h"
+#include "qemu/rcu.h"
+
+typedef struct QemuLogFile {
+    struct rcu_head rcu;
+    FILE *fd;
+} QemuLogFile;
 
 /* Private global variable, don't use */
-extern FILE *qemu_logfile;
+extern QemuLogFile *qemu_logfile;
+
 
 /* 
  * The new API:
@@ -25,7 +32,16 @@ static inline bool qemu_log_enabled(void)
  */
 static inline bool qemu_log_separate(void)
 {
-    return qemu_logfile != NULL && qemu_logfile != stderr;
+    QemuLogFile *logfile;
+    bool res = false;
+
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile && logfile->fd != stderr) {
+        res = true;
+    }
+    rcu_read_unlock();
+    return res;
 }
 
 #define CPU_LOG_TB_OUT_ASM (1 << 0)
@@ -53,14 +69,25 @@ static inline bool qemu_log_separate(void)
  * qemu_loglevel is never set when qemu_logfile is unset.
  */
 
-static inline void qemu_log_lock(void)
+static inline FILE *qemu_log_lock(void)
 {
-    qemu_flockfile(qemu_logfile);
+    QemuLogFile *logfile;
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
+        qemu_flockfile(logfile->fd);
+        return logfile->fd;
+    } else {
+        return NULL;
+    }
 }
 
-static inline void qemu_log_unlock(void)
+static inline void qemu_log_unlock(FILE *fd)
 {
-    qemu_funlockfile(qemu_logfile);
+    if (fd) {
+        qemu_funlockfile(fd);
+    }
+    rcu_read_unlock();
 }
 
 /* Logging functions: */
@@ -70,9 +97,14 @@ static inline void qemu_log_unlock(void)
 static inline void GCC_FMT_ATTR(1, 0)
 qemu_log_vprintf(const char *fmt, va_list va)
 {
-    if (qemu_logfile) {
-        vfprintf(qemu_logfile, fmt, va);
+    QemuLogFile *logfile;
+
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
+        vfprintf(logfile->fd, fmt, va);
     }
+    rcu_read_unlock();
 }
 
 /* log only if a bit is set on the current loglevel mask:
diff --git a/linux-user/main.c b/linux-user/main.c
index 6ff7851e86..8718d03ee2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -826,7 +826,7 @@ int main(int argc, char **argv, char **envp)
 
     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
         qemu_log("guest_base  0x%lx\n", guest_base);
-        log_page_dump();
+        log_page_dump("binary load");
 
         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 46a6e3a761..8685f02e7e 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -17,11 +17,10 @@
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
-
+#include "trace.h"
+#include "exec/log.h"
 #include "qemu.h"
 
-//#define DEBUG_MMAP
-
 static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER;
 static __thread int mmap_lock_count;
 
@@ -66,13 +65,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
     abi_ulong end, host_start, host_end, addr;
     int prot1, ret;
 
-#ifdef DEBUG_MMAP
-    printf("mprotect: start=0x" TARGET_ABI_FMT_lx
-           "len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c\n", start, len,
-           prot & PROT_READ ? 'r' : '-',
-           prot & PROT_WRITE ? 'w' : '-',
-           prot & PROT_EXEC ? 'x' : '-');
-#endif
+    trace_target_mprotect(start, len, prot);
 
     if ((start & ~TARGET_PAGE_MASK) != 0)
         return -TARGET_EINVAL;
@@ -369,32 +362,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
     abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
 
     mmap_lock();
-#ifdef DEBUG_MMAP
-    {
-        printf("mmap: start=0x" TARGET_ABI_FMT_lx
-               " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=",
-               start, len,
-               prot & PROT_READ ? 'r' : '-',
-               prot & PROT_WRITE ? 'w' : '-',
-               prot & PROT_EXEC ? 'x' : '-');
-        if (flags & MAP_FIXED)
-            printf("MAP_FIXED ");
-        if (flags & MAP_ANONYMOUS)
-            printf("MAP_ANON ");
-        switch(flags & MAP_TYPE) {
-        case MAP_PRIVATE:
-            printf("MAP_PRIVATE ");
-            break;
-        case MAP_SHARED:
-            printf("MAP_SHARED ");
-            break;
-        default:
-            printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE);
-            break;
-        }
-        printf("fd=%d offset=" TARGET_ABI_FMT_lx "\n", fd, offset);
-    }
-#endif
+    trace_target_mmap(start, len, prot, flags, fd, offset);
 
     if (!len) {
         errno = EINVAL;
@@ -569,11 +537,10 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
  the_end1:
     page_set_flags(start, start + len, prot | PAGE_VALID);
  the_end:
-#ifdef DEBUG_MMAP
-    printf("ret=0x" TARGET_ABI_FMT_lx "\n", start);
-    page_dump(stdout);
-    printf("\n");
-#endif
+    trace_target_mmap_complete(start);
+    if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
+        log_page_dump(__func__);
+    }
     tb_invalidate_phys_range(start, start + len);
     mmap_unlock();
     return start;
@@ -628,11 +595,8 @@ int target_munmap(abi_ulong start, abi_ulong len)
     abi_ulong end, real_start, real_end, addr;
     int prot, ret;
 
-#ifdef DEBUG_MMAP
-    printf("munmap: start=0x" TARGET_ABI_FMT_lx " len=0x"
-           TARGET_ABI_FMT_lx "\n",
-           start, len);
-#endif
+    trace_target_munmap(start, len);
+
     if (start & ~TARGET_PAGE_MASK)
         return -TARGET_EINVAL;
     len = TARGET_PAGE_ALIGN(len);
diff --git a/linux-user/trace-events b/linux-user/trace-events
index 6df234bbb6..f6de1b8bef 100644
--- a/linux-user/trace-events
+++ b/linux-user/trace-events
@@ -11,3 +11,9 @@ user_handle_signal(void *env, int target_sig) "env=%p signal %d"
 user_host_signal(void *env, int host_sig, int target_sig) "env=%p signal %d (target %d("
 user_queue_signal(void *env, int target_sig) "env=%p signal %d"
 user_s390x_restore_sigregs(void *env, uint64_t sc_psw_addr, uint64_t env_psw_addr) "env=%p frame psw.addr 0x%"PRIx64 " current psw.addr 0x%"PRIx64
+
+# mmap.c
+target_mprotect(uint64_t start, uint64_t len, int flags) "start=0x%"PRIx64 " len=0x%"PRIx64 " prot=0x%x"
+target_mmap(uint64_t start, uint64_t len, int pflags, int mflags, int fd, uint64_t offset) "start=0x%"PRIx64 " len=0x%"PRIx64 " prot=0x%x flags=0x%x fd=%d offset=0x%"PRIx64
+target_mmap_complete(uint64_t retaddr) "retaddr=0x%"PRIx64
+target_munmap(uint64_t start, uint64_t len) "start=0x%"PRIx64" len=0x%"PRIx64
diff --git a/net/can/can_socketcan.c b/net/can/can_socketcan.c
index 8a6ffad40c..29bfacd4f8 100644
--- a/net/can/can_socketcan.c
+++ b/net/can/can_socketcan.c
@@ -76,8 +76,7 @@ QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data)
 static void can_host_socketcan_display_msg(struct qemu_can_frame *msg)
 {
     int i;
-
-    qemu_log_lock();
+    FILE *logfile = qemu_log_lock();
     qemu_log("[cansocketcan]: %03X [%01d] %s %s",
              msg->can_id & QEMU_CAN_EFF_MASK,
              msg->can_dlc,
@@ -89,7 +88,7 @@ static void can_host_socketcan_display_msg(struct qemu_can_frame *msg)
     }
     qemu_log("\n");
     qemu_log_flush();
-    qemu_log_unlock();
+    qemu_log_unlock(logfile);
 }
 
 static void can_host_socketcan_read(void *opaque)
diff --git a/target/cris/translate.c b/target/cris/translate.c
index e752bd0609..cb57516a44 100644
--- a/target/cris/translate.c
+++ b/target/cris/translate.c
@@ -3273,11 +3273,11 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
 #if !DISAS_CRIS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(pc_start)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("--------------\n");
         qemu_log("IN: %s\n", lookup_symbol(pc_start));
         log_target_disas(cs, pc_start, dc->pc - pc_start);
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 #endif
diff --git a/target/i386/translate.c b/target/i386/translate.c
index 77e932d827..7c99ef1385 100644
--- a/target/i386/translate.c
+++ b/target/i386/translate.c
@@ -2502,14 +2502,15 @@ static void gen_unknown_opcode(CPUX86State *env, DisasContext *s)
     gen_illegal_opcode(s);
 
     if (qemu_loglevel_mask(LOG_UNIMP)) {
+        FILE *logfile = qemu_log_lock();
         target_ulong pc = s->pc_start, end = s->pc;
-        qemu_log_lock();
+
         qemu_log("ILLOPC: " TARGET_FMT_lx ":", pc);
         for (; pc < end; ++pc) {
             qemu_log(" %02x", cpu_ldub_code(env, pc));
         }
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 }
 
diff --git a/target/lm32/translate.c b/target/lm32/translate.c
index 778cae1e81..73db9654d6 100644
--- a/target/lm32/translate.c
+++ b/target/lm32/translate.c
@@ -1137,10 +1137,10 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(pc_start)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("\n");
         log_target_disas(cs, pc_start, dc->pc - pc_start);
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 }
diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index bdc7d5326a..525115b041 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -1765,10 +1765,10 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
 #if !SIM_COMPAT
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(pc_start)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("--------------\n");
         log_target_disas(cs, pc_start, dc->pc - pc_start);
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 #endif
diff --git a/target/nios2/translate.c b/target/nios2/translate.c
index e17656e66f..82107bf270 100644
--- a/target/nios2/translate.c
+++ b/target/nios2/translate.c
@@ -892,11 +892,11 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(tb->pc)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("IN: %s\n", lookup_symbol(tb->pc));
         log_target_disas(cs, tb->pc, dc->pc - tb->pc);
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 }
diff --git a/target/tilegx/translate.c b/target/tilegx/translate.c
index 68dd4aa2d8..abce7e1c75 100644
--- a/target/tilegx/translate.c
+++ b/target/tilegx/translate.c
@@ -2388,7 +2388,6 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
     dc->zero = NULL;
 
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)) {
-        qemu_log_lock();
         qemu_log("IN: %s\n", lookup_symbol(pc_start));
     }
     gen_tb_start(tb);
@@ -2417,11 +2416,6 @@ void gen_intermediate_code(CPUState *cs, TranslationBlock *tb, int max_insns)
     gen_tb_end(tb, num_insns);
     tb->size = dc->pc - pc_start;
     tb->icount = num_insns;
-
-    if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)) {
-        qemu_log("\n");
-        qemu_log_unlock();
-    }
 }
 
 void restore_state_to_opc(CPUTLGState *env, TranslationBlock *tb,
diff --git a/target/unicore32/translate.c b/target/unicore32/translate.c
index 0e01f35856..0f6891b8aa 100644
--- a/target/unicore32/translate.c
+++ b/target/unicore32/translate.c
@@ -1994,12 +1994,12 @@ done_generating:
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)
         && qemu_log_in_addr_range(pc_start)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("----------------\n");
         qemu_log("IN: %s\n", lookup_symbol(pc_start));
         log_target_disas(cs, pc_start, dc->pc - pc_start);
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
     tb->size = dc->pc - pc_start;
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 5475d49ed1..4f616ba38b 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1085,7 +1085,7 @@ void tcg_prologue_init(TCGContext *s)
 
 #ifdef DEBUG_DISAS
     if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("PROLOGUE: [size=%zu]\n", prologue_size);
         if (s->data_gen_ptr) {
             size_t code_size = s->data_gen_ptr - buf0;
@@ -1110,7 +1110,7 @@ void tcg_prologue_init(TCGContext *s)
         }
         qemu_log("\n");
         qemu_log_flush();
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 
@@ -2114,9 +2114,17 @@ static void tcg_dump_ops(TCGContext *s, bool have_prefs)
         }
 
         if (have_prefs || op->life) {
-            for (; col < 40; ++col) {
-                putc(' ', qemu_logfile);
+
+            QemuLogFile *logfile;
+
+            rcu_read_lock();
+            logfile = atomic_rcu_read(&qemu_logfile);
+            if (logfile) {
+                for (; col < 40; ++col) {
+                    putc(' ', logfile->fd);
+                }
             }
+            rcu_read_unlock();
         }
 
         if (op->life) {
@@ -4041,11 +4049,11 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
 #ifdef DEBUG_DISAS
     if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP)
                  && qemu_log_in_addr_range(tb->pc))) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("OP:\n");
         tcg_dump_ops(s, false);
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 
@@ -4086,11 +4094,11 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
 #ifdef DEBUG_DISAS
         if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP_IND)
                      && qemu_log_in_addr_range(tb->pc))) {
-            qemu_log_lock();
+            FILE *logfile = qemu_log_lock();
             qemu_log("OP before indirect lowering:\n");
             tcg_dump_ops(s, false);
             qemu_log("\n");
-            qemu_log_unlock();
+            qemu_log_unlock(logfile);
         }
 #endif
         /* Replace indirect temps with direct temps.  */
@@ -4107,11 +4115,11 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
 #ifdef DEBUG_DISAS
     if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP_OPT)
                  && qemu_log_in_addr_range(tb->pc))) {
-        qemu_log_lock();
+        FILE *logfile = qemu_log_lock();
         qemu_log("OP after optimization and liveness analysis:\n");
         tcg_dump_ops(s, true);
         qemu_log("\n");
-        qemu_log_unlock();
+        qemu_log_unlock(logfile);
     }
 #endif
 
diff --git a/tests/docker/common.rc b/tests/docker/common.rc
index 512202b0a1..02cd67a8c5 100755
--- a/tests/docker/common.rc
+++ b/tests/docker/common.rc
@@ -53,12 +53,7 @@ check_qemu()
         INVOCATION="$@"
     fi
 
-    if command -v gtester > /dev/null 2>&1 && \
-           gtester --version > /dev/null 2>&1; then
-        make $MAKEFLAGS $INVOCATION
-    else
-        echo "No working gtester, skipping make $INVOCATION"
-    fi
+    make $MAKEFLAGS $INVOCATION
 }
 
 test_fail()
diff --git a/tests/hd-geo-test.c b/tests/hd-geo-test.c
index 7e86c5416c..a249800544 100644
--- a/tests/hd-geo-test.c
+++ b/tests/hd-geo-test.c
@@ -34,8 +34,13 @@ static char *create_test_img(int secs)
     fd = mkstemp(template);
     g_assert(fd >= 0);
     ret = ftruncate(fd, (off_t)secs * 512);
-    g_assert(ret == 0);
     close(fd);
+
+    if (ret) {
+        free(template);
+        template = NULL;
+    }
+
     return template;
 }
 
@@ -934,6 +939,10 @@ int main(int argc, char **argv)
     for (i = 0; i < backend_last; i++) {
         if (img_secs[i] >= 0) {
             img_file_name[i] = create_test_img(img_secs[i]);
+            if (!img_file_name[i]) {
+                g_test_message("Could not create test images.");
+                goto test_add_done;
+            }
         } else {
             img_file_name[i] = NULL;
         }
@@ -965,6 +974,7 @@ int main(int argc, char **argv)
                        "skipping hd-geo/override/* tests");
     }
 
+test_add_done:
     ret = g_test_run();
 
     for (i = 0; i < backend_last; i++) {
diff --git a/tests/qemu-iotests/005 b/tests/qemu-iotests/005
index 58442762fe..b6d03ac37d 100755
--- a/tests/qemu-iotests/005
+++ b/tests/qemu-iotests/005
@@ -59,10 +59,7 @@ fi
 # Sanity check: For raw, we require a file system that permits the creation
 # of a HUGE (but very sparse) file. Check we can create it before continuing.
 if [ "$IMGFMT" = "raw" ]; then
-    if ! truncate --size=5T "$TEST_IMG"; then
-        _notrun "file system on $TEST_DIR does not support large enough files"
-    fi
-    rm "$TEST_IMG"
+    _require_large_file 5T
 fi
 
 echo
diff --git a/tests/qemu-iotests/060 b/tests/qemu-iotests/060
index b91d8321bb..d96f17a484 100755
--- a/tests/qemu-iotests/060
+++ b/tests/qemu-iotests/060
@@ -49,6 +49,9 @@ _supported_fmt qcow2
 _supported_proto file
 _supported_os Linux
 
+# The repair process will create a large file - so check for availability first
+_require_large_file 64G
+
 rt_offset=65536  # 0x10000 (XXX: just an assumption)
 rb_offset=131072 # 0x20000 (XXX: just an assumption)
 l1_offset=196608 # 0x30000 (XXX: just an assumption)
diff --git a/tests/qemu-iotests/079 b/tests/qemu-iotests/079
index 81f0c21f53..78536d3bbf 100755
--- a/tests/qemu-iotests/079
+++ b/tests/qemu-iotests/079
@@ -39,6 +39,9 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _supported_fmt qcow2
 _supported_proto file nfs
 
+# Some containers (e.g. non-x86 on Travis) do not allow large files
+_require_large_file 4G
+
 echo "=== Check option preallocation and cluster_size ==="
 echo
 cluster_sizes="16384 32768 65536 131072 262144 524288 1048576 2097152 4194304"
diff --git a/tests/qemu-iotests/220 b/tests/qemu-iotests/220
index 2d62c5dcac..15159270d3 100755
--- a/tests/qemu-iotests/220
+++ b/tests/qemu-iotests/220
@@ -42,10 +42,8 @@ echo "== Creating huge file =="
 
 # Sanity check: We require a file system that permits the creation
 # of a HUGE (but very sparse) file.  tmpfs works, ext4 does not.
-if ! truncate --size=513T "$TEST_IMG"; then
-    _notrun "file system on $TEST_DIR does not support large enough files"
-fi
-rm "$TEST_IMG"
+_require_large_file 513T
+
 IMGOPTS='cluster_size=2M,refcount_bits=1' _make_test_img 513T
 
 echo "== Populating refcounts =="
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 0cc8acc9ed..6f0582c79a 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -643,5 +643,15 @@ _require_drivers()
     done
 }
 
+# Check that we have a file system that allows huge (but very sparse) files
+#
+_require_large_file()
+{
+    if ! truncate --size="$1" "$TEST_IMG"; then
+        _notrun "file system on $TEST_DIR does not support large enough files"
+    fi
+    rm "$TEST_IMG"
+}
+
 # make sure this script returns success
 true
diff --git a/tests/tcg/Makefile.prereqs b/tests/tcg/Makefile.prereqs
index 7494b31b95..9a29604a83 100644
--- a/tests/tcg/Makefile.prereqs
+++ b/tests/tcg/Makefile.prereqs
@@ -13,6 +13,6 @@ DOCKER_IMAGE:=
 
 ifneq ($(DOCKER_IMAGE),)
 build-tcg-tests-$(PROBE_TARGET): docker-image-$(DOCKER_IMAGE)
+endif
 $(BUILD_DIR)/tests/tcg/config_$(PROBE_TARGET).mak: config-host.mak
 config-host.mak: $(SRC_PATH)/tests/tcg/configure.sh
-endif
diff --git a/tests/tcg/configure.sh b/tests/tcg/configure.sh
index 6c4a471aea..210e68396f 100755
--- a/tests/tcg/configure.sh
+++ b/tests/tcg/configure.sh
@@ -36,8 +36,10 @@ TMPC="${TMPDIR1}/qemu-conf.c"
 TMPE="${TMPDIR1}/qemu-conf.exe"
 
 container="no"
-if has "docker" || has "podman"; then
-  container=$($python $source_path/tests/docker/docker.py probe)
+if test $use_containers = "yes"; then
+    if has "docker" || has "podman"; then
+        container=$($python $source_path/tests/docker/docker.py probe)
+    fi
 fi
 
 # cross compilers defaults, can be overridden with --cross-cc-ARCH
diff --git a/tests/test-logging.c b/tests/test-logging.c
index a12585f70a..1e646f045d 100644
--- a/tests/test-logging.c
+++ b/tests/test-logging.c
@@ -108,6 +108,82 @@ static void test_parse_path(gconstpointer data)
     error_free_or_abort(&err);
 }
 
+static void test_logfile_write(gconstpointer data)
+{
+    QemuLogFile *logfile;
+    QemuLogFile *logfile2;
+    gchar const *dir = data;
+    Error *err = NULL;
+    g_autofree gchar *file_path;
+    g_autofree gchar *file_path1;
+    FILE *orig_fd;
+
+    /*
+     * Before starting test, set log flags, to ensure the file gets
+     * opened below with the call to qemu_set_log_filename().
+     * In cases where a logging backend other than log is used,
+     * this is needed.
+     */
+    qemu_set_log(CPU_LOG_TB_OUT_ASM);
+    file_path = g_build_filename(dir, "qemu_test_log_write0.log", NULL);
+    file_path1 = g_build_filename(dir, "qemu_test_log_write1.log", NULL);
+
+    /*
+     * Test that even if an open file handle is changed,
+     * our handle remains valid due to RCU.
+     */
+    qemu_set_log_filename(file_path, &err);
+    g_assert(!err);
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    orig_fd = logfile->fd;
+    g_assert(logfile && logfile->fd);
+    fprintf(logfile->fd, "%s 1st write to file\n", __func__);
+    fflush(logfile->fd);
+
+    /* Change the logfile and ensure that the handle is still valid. */
+    qemu_set_log_filename(file_path1, &err);
+    g_assert(!err);
+    logfile2 = atomic_rcu_read(&qemu_logfile);
+    g_assert(logfile->fd == orig_fd);
+    g_assert(logfile2->fd != logfile->fd);
+    fprintf(logfile->fd, "%s 2nd write to file\n", __func__);
+    fflush(logfile->fd);
+    rcu_read_unlock();
+}
+
+static void test_logfile_lock(gconstpointer data)
+{
+    FILE *logfile;
+    gchar const *dir = data;
+    Error *err = NULL;
+    g_autofree gchar *file_path;
+
+    file_path = g_build_filename(dir, "qemu_test_logfile_lock0.log", NULL);
+
+    /*
+     * Test the use of the logfile lock, such
+     * that even if an open file handle is closed,
+     * our handle remains valid for use due to RCU.
+     */
+    qemu_set_log_filename(file_path, &err);
+    logfile = qemu_log_lock();
+    g_assert(logfile);
+    fprintf(logfile, "%s 1st write to file\n", __func__);
+    fflush(logfile);
+
+    /*
+     * Initiate a close file and make sure our handle remains
+     * valid since we still have the logfile lock.
+     */
+    qemu_log_close();
+    fprintf(logfile, "%s 2nd write to file\n", __func__);
+    fflush(logfile);
+    qemu_log_unlock(logfile);
+
+    g_assert(!err);
+}
+
 /* Remove a directory and all its entries (non-recursive). */
 static void rmdir_full(gchar const *root)
 {
@@ -134,6 +210,10 @@ int main(int argc, char **argv)
 
     g_test_add_func("/logging/parse_range", test_parse_range);
     g_test_add_data_func("/logging/parse_path", tmp_path, test_parse_path);
+    g_test_add_data_func("/logging/logfile_write_path",
+                         tmp_path, test_logfile_write);
+    g_test_add_data_func("/logging/logfile_lock_path",
+                         tmp_path, test_logfile_lock);
 
     rc = g_test_run();
 
diff --git a/tests/test-util-filemonitor.c b/tests/test-util-filemonitor.c
index 301cd2db61..45009c69f4 100644
--- a/tests/test-util-filemonitor.c
+++ b/tests/test-util-filemonitor.c
@@ -406,10 +406,21 @@ test_file_monitor_events(void)
     char *pathdst = NULL;
     QFileMonitorTestData data;
     GHashTable *ids = g_hash_table_new(g_int64_hash, g_int64_equal);
+    char *travis_arch;
 
     qemu_mutex_init(&data.lock);
     data.records = NULL;
 
+    /*
+     * This test does not work on Travis LXD containers since some
+     * syscalls are blocked in that environment.
+     */
+    travis_arch = getenv("TRAVIS_ARCH");
+    if (travis_arch && !g_str_equal(travis_arch, "x86_64")) {
+        g_test_skip("Test does not work on non-x86 Travis containers.");
+        return;
+    }
+
     /*
      * The file monitor needs the main loop running in
      * order to receive events from inotify. We must
diff --git a/tests/vm/Makefile.include b/tests/vm/Makefile.include
index fea348e845..9e7c46a473 100644
--- a/tests/vm/Makefile.include
+++ b/tests/vm/Makefile.include
@@ -34,6 +34,7 @@ vm-help vm-test:
 	@echo "    DEBUG=1              	 - Enable verbose output on host and interactive debugging"
 	@echo "    V=1				 - Enable verbose ouput on host and guest commands"
 	@echo "    QEMU=/path/to/qemu		 - Change path to QEMU binary"
+	@echo "    QEMU_IMG=/path/to/qemu-img	 - Change path to qemu-img tool"
 
 vm-build-all: $(addprefix vm-build-, $(IMAGES))
 
diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
index 53b9515ee2..ed5dd4f3d0 100755
--- a/tests/vm/basevm.py
+++ b/tests/vm/basevm.py
@@ -152,6 +152,11 @@ def ssh_root_check(self, *cmd):
     def build_image(self, img):
         raise NotImplementedError
 
+    def exec_qemu_img(self, *args):
+        cmd = [os.environ.get("QEMU_IMG", "qemu-img")]
+        cmd.extend(list(args))
+        subprocess.check_call(cmd)
+
     def add_source_dir(self, src_dir):
         name = "data-" + hashlib.sha1(src_dir.encode("utf-8")).hexdigest()[:5]
         tarfile = os.path.join(self._tmpdir, name + ".tar")
diff --git a/tests/vm/centos b/tests/vm/centos
index b9e851f2d3..f2f0befd84 100755
--- a/tests/vm/centos
+++ b/tests/vm/centos
@@ -68,7 +68,7 @@ class CentosVM(basevm.BaseVM):
         sys.stderr.write("Extracting the image...\n")
         subprocess.check_call(["ln", "-f", cimg, img_tmp + ".xz"])
         subprocess.check_call(["xz", "--keep", "-dvf", img_tmp + ".xz"])
-        subprocess.check_call(["qemu-img", "resize", img_tmp, "50G"])
+        self.exec_qemu_img("resize", img_tmp, "50G")
         self.boot(img_tmp, extra_args = ["-cdrom", self._gen_cloud_init_iso()])
         self.wait_ssh()
         self.ssh_root_check("touch /etc/cloud/cloud-init.disabled")
diff --git a/tests/vm/fedora b/tests/vm/fedora
index 7fec1479fb..8e270fc0f0 100755
--- a/tests/vm/fedora
+++ b/tests/vm/fedora
@@ -74,9 +74,7 @@ class FedoraVM(basevm.BaseVM):
 
         self.print_step("Preparing iso and disk image")
         subprocess.check_call(["cp", "-f", cimg, iso])
-        subprocess.check_call(["qemu-img", "create", "-f", "qcow2",
-                               img_tmp, self.size])
-
+        self.exec_qemu_img("create", "-f", "qcow2", img_tmp, self.size)
         self.print_step("Booting installer")
         self.boot(img_tmp, extra_args = [
             "-bios", "pc-bios/bios-256k.bin",
diff --git a/tests/vm/freebsd b/tests/vm/freebsd
index 2a19461a90..1825cc5821 100755
--- a/tests/vm/freebsd
+++ b/tests/vm/freebsd
@@ -82,8 +82,7 @@ class FreeBSDVM(basevm.BaseVM):
         self.print_step("Preparing iso and disk image")
         subprocess.check_call(["cp", "-f", cimg, iso_xz])
         subprocess.check_call(["xz", "-dvf", iso_xz])
-        subprocess.check_call(["qemu-img", "create", "-f", "qcow2",
-                               img_tmp, self.size])
+        self.exec_qemu_img("create", "-f", "qcow2", img_tmp, self.size)
 
         self.print_step("Booting installer")
         self.boot(img_tmp, extra_args = [
diff --git a/tests/vm/netbsd b/tests/vm/netbsd
index 611e6cc5b5..ec6f3563b2 100755
--- a/tests/vm/netbsd
+++ b/tests/vm/netbsd
@@ -77,8 +77,7 @@ class NetBSDVM(basevm.BaseVM):
 
         self.print_step("Preparing iso and disk image")
         subprocess.check_call(["ln", "-f", cimg, iso])
-        subprocess.check_call(["qemu-img", "create", "-f", "qcow2",
-                               img_tmp, self.size])
+        self.exec_qemu_img("create", "-f", "qcow2", img_tmp, self.size)
 
         self.print_step("Booting installer")
         self.boot(img_tmp, extra_args = [
diff --git a/tests/vm/openbsd b/tests/vm/openbsd
index b92c39f89a..6df5162dbf 100755
--- a/tests/vm/openbsd
+++ b/tests/vm/openbsd
@@ -73,8 +73,7 @@ class OpenBSDVM(basevm.BaseVM):
 
         self.print_step("Preparing iso and disk image")
         subprocess.check_call(["cp", "-f", cimg, iso])
-        subprocess.check_call(["qemu-img", "create", "-f", "qcow2",
-                               img_tmp, self.size])
+        self.exec_qemu_img("create", "-f", "qcow2", img_tmp, self.size)
 
         self.print_step("Booting installer")
         self.boot(img_tmp, extra_args = [
diff --git a/tests/vm/ubuntu.i386 b/tests/vm/ubuntu.i386
index f611bebdc9..3834cd7a8d 100755
--- a/tests/vm/ubuntu.i386
+++ b/tests/vm/ubuntu.i386
@@ -70,7 +70,7 @@ class UbuntuX86VM(basevm.BaseVM):
             sha256sum="28969840626d1ea80bb249c08eef1a4533e8904aa51a327b40f37ac4b4ff04ef")
         img_tmp = img + ".tmp"
         subprocess.check_call(["cp", "-f", cimg, img_tmp])
-        subprocess.check_call(["qemu-img", "resize", img_tmp, "50G"])
+        self.exec_qemu_img("resize", img_tmp, "50G")
         self.boot(img_tmp, extra_args = ["-cdrom", self._gen_cloud_init_iso()])
         self.wait_ssh()
         self.ssh_root_check("touch /etc/cloud/cloud-init.disabled")
diff --git a/trace/control.c b/trace/control.c
index d9cafc161b..0fb8124160 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -98,38 +98,6 @@ TraceEvent *trace_event_name(const char *name)
     return NULL;
 }
 
-static bool pattern_glob(const char *pat, const char *ev)
-{
-    while (*pat != '\0' && *ev != '\0') {
-        if (*pat == *ev) {
-            pat++;
-            ev++;
-        }
-        else if (*pat == '*') {
-            if (pattern_glob(pat, ev+1)) {
-                return true;
-            } else if (pattern_glob(pat+1, ev)) {
-                return true;
-            } else {
-                return false;
-            }
-        } else {
-            return false;
-        }
-    }
-
-    while (*pat == '*') {
-        pat++;
-    }
-
-    if (*pat == '\0' && *ev == '\0') {
-        return true;
-    } else {
-        return false;
-    }
-}
-
-
 void trace_event_iter_init(TraceEventIter *iter, const char *pattern)
 {
     iter->event = 0;
@@ -148,8 +116,7 @@ TraceEvent *trace_event_iter_next(TraceEventIter *iter)
             iter->group++;
         }
         if (!iter->pattern ||
-            pattern_glob(iter->pattern,
-                         trace_event_get_name(ev))) {
+            g_pattern_match_simple(iter->pattern, trace_event_get_name(ev))) {
             return ev;
         }
     }
diff --git a/util/log.c b/util/log.c
index 1ca13059ee..867264da8d 100644
--- a/util/log.c
+++ b/util/log.c
@@ -24,9 +24,11 @@
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "trace/control.h"
+#include "qemu/thread.h"
 
 static char *logfilename;
-FILE *qemu_logfile;
+static QemuMutex qemu_logfile_mutex;
+QemuLogFile *qemu_logfile;
 int qemu_loglevel;
 static int log_append = 0;
 static GArray *debug_regions;
@@ -35,10 +37,14 @@ static GArray *debug_regions;
 int qemu_log(const char *fmt, ...)
 {
     int ret = 0;
-    if (qemu_logfile) {
+    QemuLogFile *logfile;
+
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
         va_list ap;
         va_start(ap, fmt);
-        ret = vfprintf(qemu_logfile, fmt, ap);
+        ret = vfprintf(logfile->fd, fmt, ap);
         va_end(ap);
 
         /* Don't pass back error results.  */
@@ -46,57 +52,91 @@ int qemu_log(const char *fmt, ...)
             ret = 0;
         }
     }
+    rcu_read_unlock();
     return ret;
 }
 
+static void __attribute__((__constructor__)) qemu_logfile_init(void)
+{
+    qemu_mutex_init(&qemu_logfile_mutex);
+}
+
+static void qemu_logfile_free(QemuLogFile *logfile)
+{
+    g_assert(logfile);
+
+    if (logfile->fd != stderr) {
+        fclose(logfile->fd);
+    }
+    g_free(logfile);
+}
+
 static bool log_uses_own_buffers;
 
 /* enable or disable low levels log */
 void qemu_set_log(int log_flags)
 {
+    bool need_to_open_file = false;
+    QemuLogFile *logfile;
+
     qemu_loglevel = log_flags;
 #ifdef CONFIG_TRACE_LOG
     qemu_loglevel |= LOG_TRACE;
 #endif
-    if (!qemu_logfile &&
-        (is_daemonized() ? logfilename != NULL : qemu_loglevel)) {
+    /*
+     * In all cases we only log if qemu_loglevel is set.
+     * Also:
+     *   If not daemonized we will always log either to stderr
+     *     or to a file (if there is a logfilename).
+     *   If we are daemonized,
+     *     we will only log if there is a logfilename.
+     */
+    if (qemu_loglevel && (!is_daemonized() || logfilename)) {
+        need_to_open_file = true;
+    }
+    qemu_mutex_lock(&qemu_logfile_mutex);
+    if (qemu_logfile && !need_to_open_file) {
+        logfile = qemu_logfile;
+        atomic_rcu_set(&qemu_logfile, NULL);
+        call_rcu(logfile, qemu_logfile_free, rcu);
+    } else if (!qemu_logfile && need_to_open_file) {
+        logfile = g_new0(QemuLogFile, 1);
         if (logfilename) {
-            qemu_logfile = fopen(logfilename, log_append ? "a" : "w");
-            if (!qemu_logfile) {
+            logfile->fd = fopen(logfilename, log_append ? "a" : "w");
+            if (!logfile->fd) {
+                g_free(logfile);
                 perror(logfilename);
                 _exit(1);
             }
             /* In case we are a daemon redirect stderr to logfile */
             if (is_daemonized()) {
-                dup2(fileno(qemu_logfile), STDERR_FILENO);
-                fclose(qemu_logfile);
+                dup2(fileno(logfile->fd), STDERR_FILENO);
+                fclose(logfile->fd);
                 /* This will skip closing logfile in qemu_log_close() */
-                qemu_logfile = stderr;
+                logfile->fd = stderr;
             }
         } else {
             /* Default to stderr if no log file specified */
             assert(!is_daemonized());
-            qemu_logfile = stderr;
+            logfile->fd = stderr;
         }
         /* must avoid mmap() usage of glibc by setting a buffer "by hand" */
         if (log_uses_own_buffers) {
             static char logfile_buf[4096];
 
-            setvbuf(qemu_logfile, logfile_buf, _IOLBF, sizeof(logfile_buf));
+            setvbuf(logfile->fd, logfile_buf, _IOLBF, sizeof(logfile_buf));
         } else {
 #if defined(_WIN32)
             /* Win32 doesn't support line-buffering, so use unbuffered output. */
-            setvbuf(qemu_logfile, NULL, _IONBF, 0);
+            setvbuf(logfile->fd, NULL, _IONBF, 0);
 #else
-            setvbuf(qemu_logfile, NULL, _IOLBF, 0);
+            setvbuf(logfile->fd, NULL, _IOLBF, 0);
 #endif
             log_append = 1;
         }
+        atomic_rcu_set(&qemu_logfile, logfile);
     }
-    if (qemu_logfile &&
-        (is_daemonized() ? logfilename == NULL : !qemu_loglevel)) {
-        qemu_log_close();
-    }
+    qemu_mutex_unlock(&qemu_logfile_mutex);
 }
 
 void qemu_log_needs_buffers(void)
@@ -113,6 +153,7 @@ void qemu_set_log_filename(const char *filename, Error **errp)
 {
     char *pidstr;
     g_free(logfilename);
+    logfilename = NULL;
 
     pidstr = strstr(filename, "%");
     if (pidstr) {
@@ -224,18 +265,29 @@ out:
 /* fflush() the log file */
 void qemu_log_flush(void)
 {
-    fflush(qemu_logfile);
+    QemuLogFile *logfile;
+
+    rcu_read_lock();
+    logfile = atomic_rcu_read(&qemu_logfile);
+    if (logfile) {
+        fflush(logfile->fd);
+    }
+    rcu_read_unlock();
 }
 
 /* Close the log file */
 void qemu_log_close(void)
 {
-    if (qemu_logfile) {
-        if (qemu_logfile != stderr) {
-            fclose(qemu_logfile);
-        }
-        qemu_logfile = NULL;
+    QemuLogFile *logfile;
+
+    qemu_mutex_lock(&qemu_logfile_mutex);
+    logfile = qemu_logfile;
+
+    if (logfile) {
+        atomic_rcu_set(&qemu_logfile, NULL);
+        call_rcu(logfile, qemu_logfile_free, rcu);
     }
+    qemu_mutex_unlock(&qemu_logfile_mutex);
 }
 
 const QEMULogItem qemu_log_items[] = {