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

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

[Ilya Leoshkevich]

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           | 25 +++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 tests/tcg/s390x/lae.c

-- 
2.43.0

[PATCH 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")
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 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           | 25 +++++++++++++++++++++++++
 2 files changed, 26 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..661e95f9978
--- /dev/null
+++ b/tests/tcg/s390x/lae.c
@@ -0,0 +1,25 @@
+/*
+ * 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;
+    int tmp;
+
+    asm("ear %[tmp],%[r]\n"
+        "lae %[r],42(%[x2],%[b2])\n"
+        "ear %[ar],%[r]\n"
+        "sar %[r],%[tmp]"
+        : [tmp] "=&r" (tmp), [r] "=&r" (r), [ar] "+r" (ar)
+        : [b2] "r" (b2), [x2] "r" (x2)
+        : "memory");
+    assert(ar == 0xffffffff00000000ULL);
+    assert(r == 100542);
+
+    return EXIT_SUCCESS;
+}
-- 
2.43.0

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

[David Hildenbrand]

On 10.01.24 00:22, Ilya Leoshkevich wrote:
> 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")
> 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;
>   }
>   

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb

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

[Thomas Huth]

On 10/01/2024 00.22, Ilya Leoshkevich wrote:
> 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           | 25 +++++++++++++++++++++++++
>   2 files changed, 26 insertions(+)
>   create mode 100644 tests/tcg/s390x/lae.c

Reviewed-by: Thomas Huth <thuth@redhat.com>

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

[Thomas Huth]

On 10/01/2024 00.22, Ilya Leoshkevich wrote:
> 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           | 25 +++++++++++++++++++++++++
>   2 files changed, 26 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..661e95f9978
> --- /dev/null
> +++ b/tests/tcg/s390x/lae.c
> @@ -0,0 +1,25 @@
> +/*
> + * 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;
> +    int tmp;
> +
> +    asm("ear %[tmp],%[r]\n"
> +        "lae %[r],42(%[x2],%[b2])\n"
> +        "ear %[ar],%[r]\n"
> +        "sar %[r],%[tmp]"
> +        : [tmp] "=&r" (tmp), [r] "=&r" (r), [ar] "+r" (ar)
> +        : [b2] "r" (b2), [x2] "r" (x2)
> +        : "memory");
> +    assert(ar == 0xffffffff00000000ULL);
> +    assert(r == 100542);
> +
> +    return EXIT_SUCCESS;
> +}

I'm sorry, but it fails when building with Clang (version 17):

.../qemu/tests/tcg/s390x/lae.c:14:9: error: invalid operand for instruction
    14 |     asm("ear %[tmp],%[r]\n"
       |         ^
<inline asm>:1:10: note: instantiated into assembly here
     1 |         ear %r2,%r1
       |                 ^
.../qemu/tests/tcg/s390x/lae.c:16:10: error: invalid operand for instruction
    16 |         "ear %[ar],%[r]\n"
       |          ^
<inline asm>:3:9: note: instantiated into assembly here
     3 | ear %r0,%r1
       |         ^
.../qemu/tests/tcg/s390x/lae.c:17:10: error: invalid operand for instruction
    17 |         "sar %[r],%[tmp]"
       |          ^
<inline asm>:4:5: note: instantiated into assembly here
     4 | sar %r1,%r2
       |     ^
3 errors generated.

Any suggestions how to fix it best?

  Thomas

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

[Ilya Leoshkevich]

On Thu, 2024-01-11 at 09:37 +0100, Thomas Huth wrote:
> On 10/01/2024 00.22, Ilya Leoshkevich wrote:
> > 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           | 25 +++++++++++++++++++++++++
> >   2 files changed, 26 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..661e95f9978
> > --- /dev/null
> > +++ b/tests/tcg/s390x/lae.c
> > @@ -0,0 +1,25 @@
> > +/*
> > + * 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;
> > +    int tmp;
> > +
> > +    asm("ear %[tmp],%[r]\n"
> > +        "lae %[r],42(%[x2],%[b2])\n"
> > +        "ear %[ar],%[r]\n"
> > +        "sar %[r],%[tmp]"
> > +        : [tmp] "=&r" (tmp), [r] "=&r" (r), [ar] "+r" (ar)
> > +        : [b2] "r" (b2), [x2] "r" (x2)
> > +        : "memory");
> > +    assert(ar == 0xffffffff00000000ULL);
> > +    assert(r == 100542);
> > +
> > +    return EXIT_SUCCESS;
> > +}
> 
> I'm sorry, but it fails when building with Clang (version 17):
> 
> .../qemu/tests/tcg/s390x/lae.c:14:9: error: invalid operand for
> instruction
>     14 |     asm("ear %[tmp],%[r]\n"
>        |         ^
> <inline asm>:1:10: note: instantiated into assembly here
>      1 |         ear %r2,%r1
>        |                 ^
> .../qemu/tests/tcg/s390x/lae.c:16:10: error: invalid operand for
> instruction
>     16 |         "ear %[ar],%[r]\n"
>        |          ^
> <inline asm>:3:9: note: instantiated into assembly here
>      3 | ear %r0,%r1
>        |         ^
> .../qemu/tests/tcg/s390x/lae.c:17:10: error: invalid operand for
> instruction
>     17 |         "sar %[r],%[tmp]"
>        |          ^
> <inline asm>:4:5: note: instantiated into assembly here
>      4 | sar %r1,%r2
>        |     ^
> 3 errors generated.
> 
> Any suggestions how to fix it best?
> 
>   Thomas
> 

clang wants %aN there, and I don't see a way to convert %rN to %aN.
Seems like I'll have to hardcode the register number. I'll send a v2.