[Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[Michael Weiser]

Hello,

below patches add support for big-endian aarch64 to linux-user. Almost
everything is already in place. The patches just set up the CPU flags as
required for big-endianess, add a distinction in uname and make sure the
instructions for the signal trampoline end up in memory little-endian.
Finally, configure is extended to allow building of a
aarch64_be-linux-user target.

With this I am able to run individual aarch64_be binaries as well as
chroot into a full-blown aarch64_be userland using binfmt_misc, running
and compiling things (Gentoo crossdev/native).

Thanks,
Michael

Michael Weiser (4):
  linux-user: Add support for big-endian aarch64
  linux-user: Add separate aarch64_be uname
  linux-user: Fix endianess of aarch64 signal trampoline
  configure: Add aarch64_be-linux-user target

 configure                                 |  9 +++++----
 default-configs/aarch64_be-linux-user.mak |  1 +
 linux-user/aarch64/target_syscall.h       |  4 ++++
 linux-user/main.c                         |  6 ++++++
 linux-user/signal.c                       | 10 +++++++---
 5 files changed, 23 insertions(+), 7 deletions(-)
 create mode 100644 default-configs/aarch64_be-linux-user.mak

-- 
2.15.1

[Qemu-devel] [PATCH 1/4] linux-user: Add support for big-endian aarch64

[Michael Weiser]

Enable big-endian mode for data accesses on aarch64 for big-endian linux
user mode. Activate it for all execution levels as documented by ARM:
Set the SCTLR EE bit for ELs 1 through 3. Additionally set bit E0E in
EL1 to enable it in EL0 as well.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
---
 linux-user/main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/linux-user/main.c b/linux-user/main.c
index 2fd2a143ed..7ea863260d 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -4611,6 +4611,12 @@ int main(int argc, char **argv, char **envp)
         }
         env->pc = regs->pc;
         env->xregs[31] = regs->sp;
+#ifdef TARGET_WORDS_BIGENDIAN
+        env->cp15.sctlr_el[1] |= SCTLR_E0E;
+        for (i = 1; i < 4; ++i) {
+            env->cp15.sctlr_el[i] |= SCTLR_EE;
+        }
+#endif
     }
 #elif defined(TARGET_ARM)
     {
-- 
2.15.1

[Qemu-devel] [PATCH 2/4] linux-user: Add separate aarch64_be uname

[Michael Weiser]

Make big-endian aarch64 systems identify as aarch64_be as expected by
big-endian userland and toolchains.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
---
 linux-user/aarch64/target_syscall.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/linux-user/aarch64/target_syscall.h b/linux-user/aarch64/target_syscall.h
index 1b62953eeb..604ab99b14 100644
--- a/linux-user/aarch64/target_syscall.h
+++ b/linux-user/aarch64/target_syscall.h
@@ -8,7 +8,11 @@ struct target_pt_regs {
     uint64_t        pstate;
 };
 
+#if defined(TARGET_WORDS_BIGENDIAN)
+#define UNAME_MACHINE "aarch64_be"
+#else
 #define UNAME_MACHINE "aarch64"
+#endif
 #define UNAME_MINIMUM_RELEASE "3.8.0"
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ       2048
-- 
2.15.1

[Qemu-devel] [PATCH 3/4] linux-user: Fix endianess of aarch64 signal trampoline

[Michael Weiser]

Since for aarch64 the signal trampoline is synthesized directly into the
signal frame we need to make sure the instructions end up little-endian.
Otherwise the wrong endianness will cause a SIGILL upon return from the
signal handler on big-endian targets.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
---
 linux-user/signal.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index dae14d4a89..eb3638f61b 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -1599,9 +1599,13 @@ static void target_setup_frame(int usig, struct target_sigaction *ka,
     if (ka->sa_flags & TARGET_SA_RESTORER) {
         return_addr = ka->sa_restorer;
     } else {
-        /* mov x8,#__NR_rt_sigreturn; svc #0 */
-        __put_user(0xd2801168, &frame->tramp[0]);
-        __put_user(0xd4000001, &frame->tramp[1]);
+        /*
+	 * mov x8,#__NR_rt_sigreturn; svc #0
+	 * Since these are instructions they need to be put as little-endian
+	 * regardless of target default or current CPU endianness.
+	 */
+        __put_user_e(0xd2801168, &frame->tramp[0], le);
+        __put_user_e(0xd4000001, &frame->tramp[1], le);
         return_addr = frame_addr + offsetof(struct target_rt_sigframe, tramp);
     }
     env->xregs[0] = usig;
-- 
2.15.1

[Qemu-devel] [PATCH 4/4] configure: Add aarch64_be-linux-user target

[Michael Weiser]

Add target aarch64_be-linux-user. This allows a qemu-aarch64_be binary
to be built that will run big-endian aarch64 binaries.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
---
 configure                                 | 9 +++++----
 default-configs/aarch64_be-linux-user.mak | 1 +
 2 files changed, 6 insertions(+), 4 deletions(-)
 create mode 100644 default-configs/aarch64_be-linux-user.mak

diff --git a/configure b/configure
index 9c8aa5a98b..03d95340d8 100755
--- a/configure
+++ b/configure
@@ -657,7 +657,7 @@ case "$cpu" in
     cpu="arm"
     supported_cpu="yes"
   ;;
-  aarch64)
+  aarch64|aarch64_be)
     cpu="aarch64"
     supported_cpu="yes"
   ;;
@@ -6345,7 +6345,7 @@ if test "$linux" = "yes" ; then
   s390x)
     linux_arch=s390
     ;;
-  aarch64)
+  aarch64|aarch64_be)
     linux_arch=arm64
     ;;
   mips64)
@@ -6369,7 +6369,7 @@ target_name=$(echo $target | cut -d '-' -f 1)
 target_bigendian="no"
 
 case "$target_name" in
-  armeb|hppa|lm32|m68k|microblaze|mips|mipsn32|mips64|moxie|or1k|ppc|ppcemb|ppc64|ppc64abi32|s390x|sh4eb|sparc|sparc64|sparc32plus|xtensaeb)
+  armeb|aarch64_be|hppa|lm32|m68k|microblaze|mips|mipsn32|mips64|moxie|or1k|ppc|ppcemb|ppc64|ppc64abi32|s390x|sh4eb|sparc|sparc64|sparc32plus|xtensaeb)
   target_bigendian=yes
   ;;
 esac
@@ -6424,7 +6424,8 @@ case "$target_name" in
     mttcg="yes"
     gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
   ;;
-  aarch64)
+  aarch64|aarch64_be)
+    TARGET_ARCH=aarch64
     TARGET_BASE_ARCH=arm
     bflt="yes"
     mttcg="yes"
diff --git a/default-configs/aarch64_be-linux-user.mak b/default-configs/aarch64_be-linux-user.mak
new file mode 100644
index 0000000000..a69d9d2e41
--- /dev/null
+++ b/default-configs/aarch64_be-linux-user.mak
@@ -0,0 +1 @@
+# Default configuration for aarch64_be-linux-user
-- 
2.15.1

Re: [Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[Laurent Vivier]

Le 19/12/2017 à 16:16, Michael Weiser a écrit :
> Hello,
> 
> below patches add support for big-endian aarch64 to linux-user. Almost
> everything is already in place. The patches just set up the CPU flags as
> required for big-endianess, add a distinction in uname and make sure the
> instructions for the signal trampoline end up in memory little-endian.
> Finally, configure is extended to allow building of a
> aarch64_be-linux-user target.
> 
> With this I am able to run individual aarch64_be binaries as well as
> chroot into a full-blown aarch64_be userland using binfmt_misc, running
> and compiling things (Gentoo crossdev/native).

Could you also update scripts/qemu-binfmt-conf.sh for the aarch64_be magic?

Thanks,
Laurent

Re: [Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[Michael Weiser]

Hello Laurent,

On Tue, Dec 19, 2017 at 05:17:35PM +0100, Laurent Vivier wrote:

> > below patches add support for big-endian aarch64 to linux-user. Almost

> Could you also update scripts/qemu-binfmt-conf.sh for the aarch64_be magic?

Done. v2 forthcoming.
-- 
Bye,
Michael

Re: [Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[no-reply]

Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20171219151636.5162-1-michael.weiser@gmx.de
Subject: [Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

git config --local diff.renamelimit 0
git config --local diff.renames True

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
5ac57ff210 configure: Add aarch64_be-linux-user target
07335652c6 linux-user: Fix endianess of aarch64 signal trampoline
ee4c6e2e72 linux-user: Add separate aarch64_be uname
1b214cd96a linux-user: Add support for big-endian aarch64

=== OUTPUT BEGIN ===
Checking PATCH 1/4: linux-user: Add support for big-endian aarch64...
Checking PATCH 2/4: linux-user: Add separate aarch64_be uname...
Checking PATCH 3/4: linux-user: Fix endianess of aarch64 signal trampoline...
ERROR: code indent should never use tabs
#26: FILE: linux-user/signal.c:1603:
+^I * mov x8,#__NR_rt_sigreturn; svc #0$

ERROR: code indent should never use tabs
#27: FILE: linux-user/signal.c:1604:
+^I * Since these are instructions they need to be put as little-endian$

ERROR: code indent should never use tabs
#28: FILE: linux-user/signal.c:1605:
+^I * regardless of target default or current CPU endianness.$

ERROR: code indent should never use tabs
#29: FILE: linux-user/signal.c:1606:
+^I */$

total: 4 errors, 0 warnings, 16 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Checking PATCH 4/4: configure: Add aarch64_be-linux-user target...
=== OUTPUT END ===

Test command exited with code: 1


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Re: [Qemu-devel] [PATCH 0/4] Add aarch64_be-linux-user target

[Richard Henderson]

On 12/19/2017 07:16 AM, Michael Weiser wrote:
> Michael Weiser (4):
>   linux-user: Add support for big-endian aarch64
>   linux-user: Add separate aarch64_be uname
>   linux-user: Fix endianess of aarch64 signal trampoline
>   configure: Add aarch64_be-linux-user target

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~