Merge remote-tracking branch 'remotes/stsquad/tags/pull-6.0-rc2-fixes-060421-1' into staging

Testing updates:

  - fix x86_64 cross compilers
  - don't use registry for non-x86 containers
  - add valid host types for given cross compile containers
  - clean up i386 code16 test with explicit -no-pie
  - relax sha1.py gdbstub test
  - add more gdbstub documentation
  - remove annoying warning on gitlab
  - test dtrace backend in gitlab

# gpg: Signature made Tue 06 Apr 2021 15:55:53 BST
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-6.0-rc2-fixes-060421-1:
  gitlab-ci.yml: Test the dtrace backend in one of the jobs
  gitlab-ci.yml: Fix the filtering for the git submodules
  docs/system/gdb.rst: Document how to debug multicore machines
  docs/system/gdb.rst: Add some more heading structure
  tests/tcg: relax the next step precision of the gdb sha1 test
  tests/tcg/i386: force -fno-pie for test-i386
  tests/tcg/i386: expand .data sections for system tests
  tests/tcg/configure.sh: make sure we pick up x86_64 cross compilers
  tests/tcg: add concept of container_hosts
  tests/docker: don't set DOCKER_REGISTRY on non-x86_64
  tests/tcg: update the defaults for x86 compilers

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

9 files changed, 126 insertions, 14 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3480d79db3..52d65d6c04 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -42,7 +42,7 @@ include:
   image: $CI_REGISTRY_IMAGE/qemu/$IMAGE:latest
   script:
     - scripts/git-submodule.sh update
-        $(grep GIT_SUBMODULES build/config-host.mak | sed 's/GIT_SUBMODULES=//')
+        $(sed -n '/GIT_SUBMODULES=/ s/.*=// p' build/config-host.mak)
     - cd build
     - find . -type f -exec touch {} +
     # Avoid recompiling by hiding ninja with NINJA=":"
@@ -223,7 +223,7 @@ build-system-centos:
   variables:
     IMAGE: centos8
     CONFIGURE_ARGS: --disable-nettle --enable-gcrypt --enable-fdt=system
-                    --enable-modules
+                    --enable-modules --enable-trace-backends=dtrace
     TARGETS: ppc64-softmmu or1k-softmmu s390x-softmmu
       x86_64-softmmu rx-softmmu sh4-softmmu nios2-softmmu
     MAKE_CHECK_ARGS: check-build
diff --git a/configure b/configure
index 8275df1506..4f374b4889 100755
--- a/configure
+++ b/configure
@@ -6299,7 +6299,7 @@ done
 (for i in $cross_cc_vars; do
   export $i
 done
-export target_list source_path use_containers
+export target_list source_path use_containers ARCH
 $source_path/tests/tcg/configure.sh)
 
 # temporary config to build submodules
diff --git a/docs/system/gdb.rst b/docs/system/gdb.rst
index 72b1e68f4e..144d083df3 100644
--- a/docs/system/gdb.rst
+++ b/docs/system/gdb.rst
@@ -45,7 +45,66 @@ Here are some useful tips in order to use gdb on system code:
 3. Use ``set architecture i8086`` to dump 16 bit code. Then use
    ``x/10i $cs*16+$eip`` to dump the code at the PC position.
 
-Advanced debugging options:
+Debugging multicore machines
+============================
+
+GDB's abstraction for debugging targets with multiple possible
+parallel flows of execution is a two layer one: it supports multiple
+"inferiors", each of which can have multiple "threads". When the QEMU
+machine has more than one CPU, QEMU exposes each CPU cluster as a
+separate "inferior", where each CPU within the cluster is a separate
+"thread". Most QEMU machine types have identical CPUs, so there is a
+single cluster which has all the CPUs in it.  A few machine types are
+heterogenous and have multiple clusters: for example the ``sifive_u``
+machine has a cluster with one E51 core and a second cluster with four
+U54 cores. Here the E51 is the only thread in the first inferior, and
+the U54 cores are all threads in the second inferior.
+
+When you connect gdb to the gdbstub, it will automatically
+connect to the first inferior; you can display the CPUs in this
+cluster using the gdb ``info thread`` command, and switch between
+them using gdb's usual thread-management commands.
+
+For multi-cluster machines, unfortunately gdb does not by default
+handle multiple inferiors, and so you have to explicitly connect
+to them. First, you must connect with the ``extended-remote``
+protocol, not ``remote``::
+
+    (gdb) target extended-remote localhost:1234
+
+Once connected, gdb will have a single inferior, for the
+first cluster. You need to create inferiors for the other
+clusters and attach to them, like this::
+
+  (gdb) add-inferior
+  Added inferior 2
+  (gdb) inferior 2
+  [Switching to inferior 2 [<null>] (<noexec>)]
+  (gdb) attach 2
+  Attaching to process 2
+  warning: No executable has been specified and target does not support
+  determining executable automatically.  Try using the "file" command.
+  0x00000000 in ?? ()
+
+Once you've done this, ``info threads`` will show CPUs in
+all the clusters you have attached to::
+
+  (gdb) info threads
+    Id   Target Id         Frame
+    1.1  Thread 1.1 (cortex-m33-arm-cpu cpu [running]) 0x00000000 in ?? ()
+  * 2.1  Thread 2.2 (cortex-m33-arm-cpu cpu [halted ]) 0x00000000 in ?? ()
+
+You probably also want to set gdb to ``schedule-multiple`` mode,
+so that when you tell gdb to ``continue`` it resumes all CPUs,
+not just those in the cluster you are currently working on::
+
+  (gdb) set schedule-multiple on
+
+Advanced debugging options
+==========================
+
+Changing single-stepping behaviour
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 The default single stepping behavior is step with the IRQs and timer
 service routines off. It is set this way because when gdb executes a
@@ -88,6 +147,8 @@ three commands you can query and set the single step behavior:
       sending: "qemu.sstep=0x5"
       received: "OK"
 
+Examining physical memory
+^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Another feature that QEMU gdbstub provides is to toggle the memory GDB
 works with, by default GDB will show the current process memory respecting
diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index 7cab761bf5..9f464cb92c 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -16,7 +16,10 @@ DOCKER_IMAGES := $(sort $(notdir $(basename $(wildcard $(DOCKER_FILES_DIR)/*.doc
 DOCKER_TARGETS := $(patsubst %,docker-image-%,$(DOCKER_IMAGES))
 # Use a global constant ccache directory to speed up repetitive builds
 DOCKER_CCACHE_DIR := $$HOME/.cache/qemu-docker-ccache
-DOCKER_REGISTRY := $(if $(REGISTRY),$(REGISTRY),registry.gitlab.com/qemu-project/qemu)
+ifeq ($(HOST_ARCH),x86_64)
+DOCKER_DEFAULT_REGISTRY := registry.gitlab.com/qemu-project/qemu
+endif
+DOCKER_REGISTRY := $(if $(REGISTRY),$(REGISTRY),$(DOCKER_DEFAULT_REGISTRY))
 
 DOCKER_TESTS := $(notdir $(shell \
 	find $(SRC_PATH)/tests/docker/ -name 'test-*' -type f))
diff --git a/tests/docker/dockerfiles/centos8.docker b/tests/docker/dockerfiles/centos8.docker
index a763d55730..a8c6c528b0 100644
--- a/tests/docker/dockerfiles/centos8.docker
+++ b/tests/docker/dockerfiles/centos8.docker
@@ -29,6 +29,7 @@ ENV PACKAGES \
     rdma-core-devel \
     spice-glib-devel \
     spice-server \
+    systemtap-sdt-devel \
     tar \
     zlib-devel
 
diff --git a/tests/tcg/configure.sh b/tests/tcg/configure.sh
index ce304f4933..fa1a4261a4 100755
--- a/tests/tcg/configure.sh
+++ b/tests/tcg/configure.sh
@@ -52,7 +52,7 @@ fi
 : ${cross_cc_hexagon="hexagon-unknown-linux-musl-clang"}
 : ${cross_cc_cflags_hexagon="-mv67 -O2 -static"}
 : ${cross_cc_hppa="hppa-linux-gnu-gcc"}
-: ${cross_cc_i386="i386-pc-linux-gnu-gcc"}
+: ${cross_cc_i386="i686-linux-gnu-gcc"}
 : ${cross_cc_cflags_i386="-m32"}
 : ${cross_cc_m68k="m68k-linux-gnu-gcc"}
 : $(cross_cc_mips64el="mips64el-linux-gnuabi64-gcc")
@@ -69,7 +69,7 @@ fi
 : ${cross_cc_cflags_sparc="-m32 -mv8plus -mcpu=ultrasparc"}
 : ${cross_cc_sparc64="sparc64-linux-gnu-gcc"}
 : ${cross_cc_cflags_sparc64="-m64 -mcpu=ultrasparc"}
-: ${cross_cc_x86_64="x86_64-pc-linux-gnu-gcc"}
+: ${cross_cc_x86_64="x86_64-linux-gnu-gcc"}
 : ${cross_cc_cflags_x86_64="-m64"}
 
 for target in $target_list; do
@@ -108,79 +108,103 @@ for target in $target_list; do
   case $target in
     aarch64-*)
       # We don't have any bigendian build tools so we only use this for AArch64
+      container_hosts="x86_64 aarch64"
       container_image=debian-arm64-test-cross
       container_cross_cc=aarch64-linux-gnu-gcc-10
       ;;
     alpha-*)
+      container_hosts=x86_64
       container_image=debian-alpha-cross
       container_cross_cc=alpha-linux-gnu-gcc
       ;;
     arm-*)
       # We don't have any bigendian build tools so we only use this for ARM
+      container_hosts="x86_64 aarch64"
       container_image=debian-armhf-cross
       container_cross_cc=arm-linux-gnueabihf-gcc
       ;;
     cris-*)
+      container_hosts=x86_64
       container_image=fedora-cris-cross
       container_cross_cc=cris-linux-gnu-gcc
       ;;
     hppa-*)
+      container_hosts=x86_64
       container_image=debian-hppa-cross
       container_cross_cc=hppa-linux-gnu-gcc
       ;;
     i386-*)
+      container_hosts=x86_64
       container_image=fedora-i386-cross
       container_cross_cc=gcc
       ;;
     m68k-*)
+      container_hosts=x86_64
       container_image=debian-m68k-cross
       container_cross_cc=m68k-linux-gnu-gcc
       ;;
     mips64el-*)
+      container_hosts=x86_64
       container_image=debian-mips64el-cross
       container_cross_cc=mips64el-linux-gnuabi64-gcc
       ;;
     mips64-*)
+      container_hosts=x86_64
       container_image=debian-mips64-cross
       container_cross_cc=mips64-linux-gnuabi64-gcc
       ;;
     mipsel-*)
+      container_hosts=x86_64
       container_image=debian-mipsel-cross
       container_cross_cc=mipsel-linux-gnu-gcc
       ;;
     mips-*)
+      container_hosts=x86_64
       container_image=debian-mips-cross
       container_cross_cc=mips-linux-gnu-gcc
       ;;
     ppc-*|ppc64abi32-*)
+      container_hosts=x86_64
       container_image=debian-powerpc-cross
       container_cross_cc=powerpc-linux-gnu-gcc
       ;;
     ppc64-*)
+      container_hosts=x86_64
       container_image=debian-ppc64-cross
       container_cross_cc=powerpc64-linux-gnu-gcc
       ;;
     ppc64le-*)
+      container_hosts=x86_64
       container_image=debian-ppc64el-cross
       container_cross_cc=powerpc64le-linux-gnu-gcc
       ;;
     riscv64-*)
+      container_hosts=x86_64
       container_image=debian-riscv64-cross
       container_cross_cc=riscv64-linux-gnu-gcc
       ;;
     s390x-*)
+      container_hosts=x86_64
       container_image=debian-s390x-cross
       container_cross_cc=s390x-linux-gnu-gcc
       ;;
     sh4-*)
+      container_hosts=x86_64
       container_image=debian-sh4-cross
       container_cross_cc=sh4-linux-gnu-gcc
       ;;
     sparc64-*)
+      container_hosts=x86_64
       container_image=debian-sparc64-cross
       container_cross_cc=sparc64-linux-gnu-gcc
       ;;
+    x86_64-*)
+      container_hosts="aarch64 ppc64el x86_64"
+      container_image=debian-amd64-cross
+      container_cross_cc=x86_64-linux-gnu-gcc
+      ;;
     xtensa*-softmmu)
+      container_hosts=x86_64
       container_image=debian-xtensa-cross
 
       # default to the dc232b cpu
@@ -257,6 +281,12 @@ for target in $target_list; do
                 echo "CROSS_CC_HAS_POWER8_VECTOR=y" >> $config_target_mak
             fi
         ;;
+        i386-linux-user)
+            if do_compiler "$target_compiler" $target_compiler_cflags \
+                -Werror -fno-pie -o $TMPE $TMPC; then
+                echo "CROSS_CC_HAS_I386_NOPIE=y" >> $config_target_mak
+            fi
+        ;;
     esac
 
     enabled_cross_compilers="$enabled_cross_compilers $target_compiler"
@@ -265,7 +295,11 @@ for target in $target_list; do
   done
 
   if test $got_cross_cc = no && test "$container" != no && test -n "$container_image"; then
-    echo "DOCKER_IMAGE=$container_image" >> $config_target_mak
-    echo "DOCKER_CROSS_CC_GUEST=$container_cross_cc" >> $config_target_mak
+      for host in $container_hosts; do
+          if test "$host" = "$ARCH"; then
+              echo "DOCKER_IMAGE=$container_image" >> $config_target_mak
+              echo "DOCKER_CROSS_CC_GUEST=$container_cross_cc" >> $config_target_mak
+          fi
+      done
   fi
 done
diff --git a/tests/tcg/i386/Makefile.target b/tests/tcg/i386/Makefile.target
index c4a6f91966..f7efaab918 100644
--- a/tests/tcg/i386/Makefile.target
+++ b/tests/tcg/i386/Makefile.target
@@ -27,13 +27,23 @@ run-plugin-test-i386-bmi2-%: QEMU_OPTS += -cpu max
 hello-i386: CFLAGS+=-ffreestanding
 hello-i386: LDFLAGS+=-nostdlib
 
-#
-# test-386 includes a couple of additional objects that need to be linked together
-#
+# test-386 includes a couple of additional objects that need to be
+# linked together, we also need a no-pie capable compiler due to the
+# non-pic calls into 16-bit mode
+ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_I386_NOPIE),)
+test-i386: CFLAGS += -fno-pie
 
 test-i386: test-i386.c test-i386-code16.S test-i386-vm86.S test-i386.h test-i386-shift.h test-i386-muldiv.h
 	$(CC) $(CFLAGS) $(LDFLAGS) $(EXTRA_CFLAGS) -o $@ \
 	   $(<D)/test-i386.c $(<D)/test-i386-code16.S $(<D)/test-i386-vm86.S -lm
+else
+test-i386:
+	$(call skip-test, "BUILD of $@", "missing -no-pie compiler support")
+run-test-i386:
+	$(call skip-test, "RUN of test-i386", "not built")
+run-plugin-test-i386-with-%:
+	$(call skip-test, "RUN of test-i386 ($*)", "not built")
+endif
 
 ifeq ($(SPEED), slow)
 
diff --git a/tests/tcg/i386/system/kernel.ld b/tests/tcg/i386/system/kernel.ld
index 92de525e93..27ea5bbe04 100644
--- a/tests/tcg/i386/system/kernel.ld
+++ b/tests/tcg/i386/system/kernel.ld
@@ -12,7 +12,7 @@ SECTIONS {
 	}
 
 	.data : {
-		*(.data)
+		*(.data*)
 		__load_en = .;
 	}
 
diff --git a/tests/tcg/multiarch/gdbstub/sha1.py b/tests/tcg/multiarch/gdbstub/sha1.py
index 2bfde49633..423b720e6d 100644
--- a/tests/tcg/multiarch/gdbstub/sha1.py
+++ b/tests/tcg/multiarch/gdbstub/sha1.py
@@ -40,7 +40,10 @@ def run_test():
 
     check_break("SHA1Init")
 
-    # check step and inspect values
+    # Check step and inspect values. We do a double next after the
+    # breakpoint as depending on the version of gdb we may step the
+    # preamble and not the first actual line of source.
+    gdb.execute("next")
     gdb.execute("next")
     val_ctx = gdb.parse_and_eval("context->state[0]")
     exp_ctx = 0x67452301