2021-05-03 13:44:26

by David Hildenbrand

[permalink] [raw]
Subject: [PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

The PoP documents:
134: The vector packed decimal facility is installed in the
z/Architecture architectural mode. When bit 134 is
one, bit 129 is also one.
135: The vector enhancements facility 1 is installed in
the z/Architecture architectural mode. When bit 135
is one, bit 129 is also one.

Looks like we confuse the vector enhancements facility 1 ("EXT") with the
Vector packed decimal facility ("BCD"). Let's fix the facility checks.

Detected while working on QEMU/tcg z14 support and only unlocking
the vector enhancements facility 1, but not the vector packed decimal
facility.

Fixes: 2583b848cad0 ("s390: report new vector facilities")
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Alexander Egorenkov <[email protected]>
Cc: Niklas Schnelle <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: [email protected]
Signed-off-by: David Hildenbrand <[email protected]>
---
arch/s390/kernel/setup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 72134f9f6ff5..5aab59ad5688 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -937,9 +937,9 @@ static int __init setup_hwcaps(void)
if (MACHINE_HAS_VX) {
elf_hwcap |= HWCAP_S390_VXRS;
if (test_facility(134))
- elf_hwcap |= HWCAP_S390_VXRS_EXT;
- if (test_facility(135))
elf_hwcap |= HWCAP_S390_VXRS_BCD;
+ if (test_facility(135))
+ elf_hwcap |= HWCAP_S390_VXRS_EXT;
if (test_facility(148))
elf_hwcap |= HWCAP_S390_VXRS_EXT2;
if (test_facility(152))
--
2.30.2


2021-05-03 13:45:05

by Christian Borntraeger

[permalink] [raw]
Subject: Re: [PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility



On 03.05.21 14:12, David Hildenbrand wrote:
> The PoP documents:
> 134: The vector packed decimal facility is installed in the
> z/Architecture architectural mode. When bit 134 is
> one, bit 129 is also one.
> 135: The vector enhancements facility 1 is installed in
> the z/Architecture architectural mode. When bit 135
> is one, bit 129 is also one.
>
> Looks like we confuse the vector enhancements facility 1 ("EXT") with the
> Vector packed decimal facility ("BCD"). Let's fix the facility checks.
>
> Detected while working on QEMU/tcg z14 support and only unlocking
> the vector enhancements facility 1, but not the vector packed decimal
> facility.
>
> Fixes: 2583b848cad0 ("s390: report new vector facilities")
> Cc: Heiko Carstens <[email protected]>
> Cc: Vasily Gorbik <[email protected]>
> Cc: Christian Borntraeger <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: Alexander Egorenkov <[email protected]>
> Cc: Niklas Schnelle <[email protected]>
> Cc: Janosch Frank <[email protected]>
> Cc: [email protected]
> Signed-off-by: David Hildenbrand <[email protected]>

Yes looks correct. This should not be noticable on real machines as you either
have both or none, but of course with virtual machine this could happen.

Reviewed-by: Christian Borntraeger <[email protected]>

> ---
> arch/s390/kernel/setup.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
> index 72134f9f6ff5..5aab59ad5688 100644
> --- a/arch/s390/kernel/setup.c
> +++ b/arch/s390/kernel/setup.c
> @@ -937,9 +937,9 @@ static int __init setup_hwcaps(void)
> if (MACHINE_HAS_VX) {
> elf_hwcap |= HWCAP_S390_VXRS;
> if (test_facility(134))
> - elf_hwcap |= HWCAP_S390_VXRS_EXT;
> - if (test_facility(135))
> elf_hwcap |= HWCAP_S390_VXRS_BCD;
> + if (test_facility(135))
> + elf_hwcap |= HWCAP_S390_VXRS_EXT;
> if (test_facility(148))
> elf_hwcap |= HWCAP_S390_VXRS_EXT2;
> if (test_facility(152))
>

2021-05-03 18:07:10

by Cornelia Huck

[permalink] [raw]
Subject: Re: [PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

On Mon, 3 May 2021 14:12:44 +0200
David Hildenbrand <[email protected]> wrote:

> The PoP documents:
> 134: The vector packed decimal facility is installed in the
> z/Architecture architectural mode. When bit 134 is
> one, bit 129 is also one.
> 135: The vector enhancements facility 1 is installed in
> the z/Architecture architectural mode. When bit 135
> is one, bit 129 is also one.
>
> Looks like we confuse the vector enhancements facility 1 ("EXT") with the
> Vector packed decimal facility ("BCD"). Let's fix the facility checks.
>
> Detected while working on QEMU/tcg z14 support and only unlocking
> the vector enhancements facility 1, but not the vector packed decimal
> facility.
>
> Fixes: 2583b848cad0 ("s390: report new vector facilities")
> Cc: Heiko Carstens <[email protected]>
> Cc: Vasily Gorbik <[email protected]>
> Cc: Christian Borntraeger <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: Alexander Egorenkov <[email protected]>
> Cc: Niklas Schnelle <[email protected]>
> Cc: Janosch Frank <[email protected]>
> Cc: [email protected]
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> arch/s390/kernel/setup.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Cornelia Huck <[email protected]>

2021-05-03 18:08:53

by Janosch Frank

[permalink] [raw]
Subject: Re: [PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

On 5/3/21 2:12 PM, David Hildenbrand wrote:
> The PoP documents:
> 134: The vector packed decimal facility is installed in the
> z/Architecture architectural mode. When bit 134 is
> one, bit 129 is also one.
> 135: The vector enhancements facility 1 is installed in
> the z/Architecture architectural mode. When bit 135
> is one, bit 129 is also one.
>
> Looks like we confuse the vector enhancements facility 1 ("EXT") with the
> Vector packed decimal facility ("BCD"). Let's fix the facility checks.
>
> Detected while working on QEMU/tcg z14 support and only unlocking
> the vector enhancements facility 1, but not the vector packed decimal
> facility.

Reviewed-by: Janosch Frank <[email protected]>

>
> Fixes: 2583b848cad0 ("s390: report new vector facilities")
> Cc: Heiko Carstens <[email protected]>
> Cc: Vasily Gorbik <[email protected]>
> Cc: Christian Borntraeger <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: Alexander Egorenkov <[email protected]>
> Cc: Niklas Schnelle <[email protected]>
> Cc: Janosch Frank <[email protected]>
> Cc: [email protected]
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> arch/s390/kernel/setup.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
> index 72134f9f6ff5..5aab59ad5688 100644
> --- a/arch/s390/kernel/setup.c
> +++ b/arch/s390/kernel/setup.c
> @@ -937,9 +937,9 @@ static int __init setup_hwcaps(void)
> if (MACHINE_HAS_VX) {
> elf_hwcap |= HWCAP_S390_VXRS;
> if (test_facility(134))
> - elf_hwcap |= HWCAP_S390_VXRS_EXT;
> - if (test_facility(135))
> elf_hwcap |= HWCAP_S390_VXRS_BCD;
> + if (test_facility(135))
> + elf_hwcap |= HWCAP_S390_VXRS_EXT;
> if (test_facility(148))
> elf_hwcap |= HWCAP_S390_VXRS_EXT2;
> if (test_facility(152))
>

2021-05-03 20:40:17

by Heiko Carstens

[permalink] [raw]
Subject: Re: [PATCH] s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

On Mon, May 03, 2021 at 02:12:44PM +0200, David Hildenbrand wrote:
> The PoP documents:
> 134: The vector packed decimal facility is installed in the
> z/Architecture architectural mode. When bit 134 is
> one, bit 129 is also one.
> 135: The vector enhancements facility 1 is installed in
> the z/Architecture architectural mode. When bit 135
> is one, bit 129 is also one.
>
> Looks like we confuse the vector enhancements facility 1 ("EXT") with the
> Vector packed decimal facility ("BCD"). Let's fix the facility checks.
>
> Detected while working on QEMU/tcg z14 support and only unlocking
> the vector enhancements facility 1, but not the vector packed decimal
> facility.
>
> Fixes: 2583b848cad0 ("s390: report new vector facilities")
> Cc: Heiko Carstens <[email protected]>
> Cc: Vasily Gorbik <[email protected]>
> Cc: Christian Borntraeger <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: Alexander Egorenkov <[email protected]>
> Cc: Niklas Schnelle <[email protected]>
> Cc: Janosch Frank <[email protected]>
> Cc: [email protected]
> Signed-off-by: David Hildenbrand <[email protected]>
> ---
> arch/s390/kernel/setup.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)

Applied, thanks!