[PATCH v2 0/2] target/s390x: Fix LAE setting a wrong access register

[PATCH v2 0/2] target/s390x: Fix LAE setting a wrong access register

[Ilya Leoshkevich]

v1: https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg01596.html
v1 -> v2: Fix building the test with clang (Thomas).



Hi,

Ido has noticed that LAE sets a wrong access register and proposed a
fix. This series fixes the issue and adds a test.

Best regards,
Ilya

Ilya Leoshkevich (2):
  target/s390x: Fix LAE setting a wrong access register
  tests/tcg/s390x: Test LOAD ADDRESS EXTENDED

 target/s390x/tcg/translate.c    |  3 ++-
 tests/tcg/s390x/Makefile.target |  1 +
 tests/tcg/s390x/lae.c           | 31 +++++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 tests/tcg/s390x/lae.c

-- 
2.43.0

[PATCH v2 1/2] target/s390x: Fix LAE setting a wrong access register

[Ilya Leoshkevich]

LAE should set the access register corresponding to the first operand,
instead, it always modifies access register 1.

Co-developed-by: Ido Plat <Ido.Plat@ibm.com>
Cc: qemu-stable@nongnu.org
Fixes: a1c7610a6879 ("target-s390x: implement LAY and LAEY instructions")
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 target/s390x/tcg/translate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 62ab2be8b12..8df00b7df9f 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -3221,6 +3221,7 @@ static DisasJumpType op_mov2e(DisasContext *s, DisasOps *o)
 {
     int b2 = get_field(s, b2);
     TCGv ar1 = tcg_temp_new_i64();
+    int r1 = get_field(s, r1);
 
     o->out = o->in2;
     o->in2 = NULL;
@@ -3244,7 +3245,7 @@ static DisasJumpType op_mov2e(DisasContext *s, DisasOps *o)
         break;
     }
 
-    tcg_gen_st32_i64(ar1, tcg_env, offsetof(CPUS390XState, aregs[1]));
+    tcg_gen_st32_i64(ar1, tcg_env, offsetof(CPUS390XState, aregs[r1]));
     return DISAS_NEXT;
 }
 
-- 
2.43.0

[PATCH v2 2/2] tests/tcg/s390x: Test LOAD ADDRESS EXTENDED

[Ilya Leoshkevich]

Add a small test to prevent regressions. Userspace runs in primary
mode, so LAE should always set the access register to 0.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tests/tcg/s390x/Makefile.target |  1 +
 tests/tcg/s390x/lae.c           | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 tests/tcg/s390x/lae.c

diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index 0e670f3f8b9..30994dcf9c2 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -44,6 +44,7 @@ TESTS+=clgebr
 TESTS+=clc
 TESTS+=laalg
 TESTS+=add-logical-with-carry
+TESTS+=lae
 
 cdsg: CFLAGS+=-pthread
 cdsg: LDFLAGS+=-pthread
diff --git a/tests/tcg/s390x/lae.c b/tests/tcg/s390x/lae.c
new file mode 100644
index 00000000000..59712b5e371
--- /dev/null
+++ b/tests/tcg/s390x/lae.c
@@ -0,0 +1,31 @@
+/*
+ * Test the LOAD ADDRESS EXTENDED instruction.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    unsigned long long ar = -1, b2 = 100000, r, x2 = 500;
+    /*
+     * Hardcode the register number, since clang does not allow using %rN in
+     * place of %aN.
+     */
+    register unsigned long long r2 __asm__("2");
+    int tmp;
+
+    asm("ear %[tmp],%%a2\n"
+        "lae %%r2,42(%[x2],%[b2])\n"
+        "ear %[ar],%%a2\n"
+        "sar %%a2,%[tmp]"
+        : [tmp] "=&r" (tmp), "=&r" (r2), [ar] "+r" (ar)
+        : [b2] "r" (b2), [x2] "r" (x2)
+        : "memory");
+    r = r2;
+    assert(ar == 0xffffffff00000000ULL);
+    assert(r == 100542);
+
+    return EXIT_SUCCESS;
+}
-- 
2.43.0