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[Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user

David Hildenbrand posted 1 patch 7 years ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20181008153204.18845-1-david@redhat.com
Test docker-clang@ubuntu failed
Test checkpatch passed
target/s390x/cpu.c | 5 +++++
1 file changed, 5 insertions(+)
[Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by David Hildenbrand 7 years ago 
linux-user should always enable AFP, otherwise our emulated binary
might crash once it tries to make use of additional floating-point
registers or instructions.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Alex Bennée <alex.bennee@linaro.org>
Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
Reported-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/cpu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 8ed4823d6e..18ba7f85a5 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
     env->cregs[0] = CR0_RESET;
     env->cregs[14] = CR14_RESET;
 
+#if defined(CONFIG_USER_ONLY)
+    /* user mode should always be allowed to use the full FPU */
+    env->cregs[0] |= CR0_AFP;
+#endif
+
     /* architectured initial value for Breaking-Event-Address register */
     env->gbea = 1;
 
-- 
2.17.1
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Thomas Huth 7 years ago 
On 2018-10-08 17:32, David Hildenbrand wrote:
> linux-user should always enable AFP, otherwise our emulated binary
> might crash once it tries to make use of additional floating-point
> registers or instructions.
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 8ed4823d6e..18ba7f85a5 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
>      env->cregs[0] = CR0_RESET;
>      env->cregs[14] = CR14_RESET;
>  
> +#if defined(CONFIG_USER_ONLY)
> +    /* user mode should always be allowed to use the full FPU */
> +    env->cregs[0] |= CR0_AFP;
> +#endif
> +
>      /* architectured initial value for Breaking-Event-Address register */
>      env->gbea = 1;
>  
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Cornelia Huck 7 years ago 
On Mon,  8 Oct 2018 17:32:04 +0200
David Hildenbrand <david@redhat.com> wrote:

> linux-user should always enable AFP, otherwise our emulated binary
> might crash once it tries to make use of additional floating-point
> registers or instructions.
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 8ed4823d6e..18ba7f85a5 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
>      env->cregs[0] = CR0_RESET;
>      env->cregs[14] = CR14_RESET;
>  
> +#if defined(CONFIG_USER_ONLY)
> +    /* user mode should always be allowed to use the full FPU */
> +    env->cregs[0] |= CR0_AFP;
> +#endif
> +
>      /* architectured initial value for Breaking-Event-Address register */
>      env->gbea = 1;
>  

I've reproduced the crash via make check-tcg, and this patch fixes it.

Thanks, applied.
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Richard Henderson 7 years ago 
On 10/8/18 8:32 AM, David Hildenbrand wrote:
> linux-user should always enable AFP, otherwise our emulated binary
> might crash once it tries to make use of additional floating-point
> registers or instructions.
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.c | 5 +++++
>  1 file changed, 5 insertions(+)

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


r~
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Alex Bennée 7 years ago 
David Hildenbrand <david@redhat.com> writes:

> linux-user should always enable AFP, otherwise our emulated binary
> might crash once it tries to make use of additional floating-point
> registers or instructions.
>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 8ed4823d6e..18ba7f85a5 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
>      env->cregs[0] = CR0_RESET;
>      env->cregs[14] = CR14_RESET;
>
> +#if defined(CONFIG_USER_ONLY)
> +    /* user mode should always be allowed to use the full FPU */
> +    env->cregs[0] |= CR0_AFP;
> +#endif
> +

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>


>      /* architectured initial value for Breaking-Event-Address register */
>      env->gbea = 1;


--
Alex Bennée
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Cornelia Huck 7 years ago 
On Mon,  8 Oct 2018 17:32:04 +0200
David Hildenbrand <david@redhat.com> wrote:

> linux-user should always enable AFP, otherwise our emulated binary
> might crash once it tries to make use of additional floating-point
> registers or instructions.
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
> Reported-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 8ed4823d6e..18ba7f85a5 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
>      env->cregs[0] = CR0_RESET;
>      env->cregs[14] = CR14_RESET;
>  
> +#if defined(CONFIG_USER_ONLY)
> +    /* user mode should always be allowed to use the full FPU */
> +    env->cregs[0] |= CR0_AFP;
> +#endif
> +
>      /* architectured initial value for Breaking-Event-Address register */
>      env->gbea = 1;
>  

In case this is applied directly:

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Cornelia Huck <cohuck@redhat.com>
Re: [Qemu-devel] [PATCH] s390x/tcg: always enable AFP for linux-user
Posted by Peter Maydell 7 years ago 
On 8 October 2018 at 17:16, Cornelia Huck <cohuck@redhat.com> wrote:
> On Mon,  8 Oct 2018 17:32:04 +0200
> David Hildenbrand <david@redhat.com> wrote:
>
>> linux-user should always enable AFP, otherwise our emulated binary
>> might crash once it tries to make use of additional floating-point
>> registers or instructions.
>>
>> Cc: Peter Maydell <peter.maydell@linaro.org>
>> Cc: Alex Bennée <alex.bennee@linaro.org>
>> Fixes: db0504154e ("s390x/tcg: check for AFP-register, BFP and DFP data exceptions")
>> Reported-by: Alex Bennée <alex.bennee@linaro.org>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>> ---
>>  target/s390x/cpu.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>> index 8ed4823d6e..18ba7f85a5 100644
>> --- a/target/s390x/cpu.c
>> +++ b/target/s390x/cpu.c
>> @@ -145,6 +145,11 @@ static void s390_cpu_full_reset(CPUState *s)
>>      env->cregs[0] = CR0_RESET;
>>      env->cregs[14] = CR14_RESET;
>>
>> +#if defined(CONFIG_USER_ONLY)
>> +    /* user mode should always be allowed to use the full FPU */
>> +    env->cregs[0] |= CR0_AFP;
>> +#endif
>> +
>>      /* architectured initial value for Breaking-Event-Address register */
>>      env->gbea = 1;
>>
>
> In case this is applied directly:
>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> Tested-by: Cornelia Huck <cohuck@redhat.com>

Thanks; I've applied it to master, and also added 'make check-tcg'
to my set of things I run as part of a merge, which should catch
this kind of bug in future.

-- PMM

Patchew 2.1-devel-b67e4c2

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