[PATCH v2 0/6] qom: Allow object to be aligned

[PATCH v2 0/6] qom: Allow object to be aligned

[Richard Henderson]

I've seen some failures on arm and s390x hosts after
enabling host vector support.  It turns out that the
malloc for these hosts does not provide 16-byte alignment.

We already have a function that can alloc with alignment,
but we need to pass this down from the structure.  We also
don't want to use this function unconditionally, because
the windows version does page allocation, which would be
overkill for the vast majority of the objects allocated.

Changes in v2:
  * Add _aligned_malloc patch for win32.  For what it's
    worth, this passes a gitlab cross-compile test.

  * Add and use qemu_max_align_t for choosing between
    g_malloc and qemu_memalign.

    I had been discussing extra checks for i386-linux with
    Eduardo, but then it occured to me that both linux libc
    posix_memalign is smart enough to not imply extra overhead.
    So qemu_memalign with alignment <= malloc alignment is
    handled easily by the system.


r~


Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: qemu-arm@nongnu.org
Cc: qemu-ppc@nongnu.org
Cc: qemu-riscv@nongnu.org
Cc: qemu-s390x@nongnu.org


Richard Henderson (6):
  util/oslib-win32: Use _aligned_malloc for qemu_try_memalign
  qom: Allow objects to be allocated with increased alignment
  target/arm: Set instance_align on CPUARM TypeInfo
  target/ppc: Set instance_align on PowerPCCPU TypeInfo
  target/riscv: Set instance_align on RISCVCPU TypeInfo
  target/s390x: Set instance_align on S390CPU TypeInfo

 include/qom/object.h            |  5 +++++
 qom/object.c                    | 36 ++++++++++++++++++++++++++++++---
 target/arm/cpu.c                |  2 ++
 target/riscv/cpu.c              |  1 +
 target/s390x/cpu.c              |  1 +
 util/oslib-win32.c              | 10 +++------
 target/ppc/translate_init.c.inc |  1 +
 7 files changed, 46 insertions(+), 10 deletions(-)

-- 
2.25.1

[PATCH v2 0/6] qom: Allow object to be aligned

[Richard Henderson]

I've seen some failures on arm and s390x hosts after
enabling host vector support.  It turns out that the
malloc for these hosts does not provide 16-byte alignment.

We already have a function that can alloc with alignment,
but we need to pass this down from the structure.  We also
don't want to use this function unconditionally, because
the windows version does page allocation, which would be
overkill for the vast majority of the objects allocated.

Changes in v2:
  * Add _aligned_malloc patch for win32.  For what it's
    worth, this passes a gitlab cross-compile test.

  * Add and use qemu_max_align_t for choosing between
    g_malloc and qemu_memalign.

    I had been discussing extra checks for i386-linux with
    Eduardo, but then it occured to me that both linux libc
    posix_memalign is smart enough to not imply extra overhead.
    So qemu_memalign with alignment <= malloc alignment is
    handled easily by the system.


r~


Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: qemu-arm@nongnu.org
Cc: qemu-ppc@nongnu.org
Cc: qemu-riscv@nongnu.org
Cc: qemu-s390x@nongnu.org


Richard Henderson (6):
  util/oslib-win32: Use _aligned_malloc for qemu_try_memalign
  qom: Allow objects to be allocated with increased alignment
  target/arm: Set instance_align on CPUARM TypeInfo
  target/ppc: Set instance_align on PowerPCCPU TypeInfo
  target/riscv: Set instance_align on RISCVCPU TypeInfo
  target/s390x: Set instance_align on S390CPU TypeInfo

 include/qom/object.h            |  5 +++++
 qom/object.c                    | 36 ++++++++++++++++++++++++++++++---
 target/arm/cpu.c                |  2 ++
 target/riscv/cpu.c              |  1 +
 target/s390x/cpu.c              |  1 +
 util/oslib-win32.c              | 10 +++------
 target/ppc/translate_init.c.inc |  1 +
 7 files changed, 46 insertions(+), 10 deletions(-)

-- 
2.25.1

[PATCH v2 1/6] util/oslib-win32: Use _aligned_malloc for qemu_try_memalign

[Richard Henderson]

We do not need or want to be allocating page sized quanta.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Stefan Weil <sw@weilnetz.de>
---
 util/oslib-win32.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index c654dafd93..8d838bf342 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -56,10 +56,8 @@ void *qemu_try_memalign(size_t alignment, size_t size)
 {
     void *ptr;
 
-    if (!size) {
-        abort();
-    }
-    ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
+    assert(size != 0);
+    ptr = _aligned_malloc(alignment, size);
     trace_qemu_memalign(alignment, size, ptr);
     return ptr;
 }
@@ -93,9 +91,7 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared)
 void qemu_vfree(void *ptr)
 {
     trace_qemu_vfree(ptr);
-    if (ptr) {
-        VirtualFree(ptr, 0, MEM_RELEASE);
-    }
+    _aligned_free(ptr);
 }
 
 void qemu_anon_ram_free(void *ptr, size_t size)
-- 
2.25.1

Re: [PATCH v2 1/6] util/oslib-win32: Use _aligned_malloc for qemu_try_memalign

[Stefan Weil]

Am 16.09.20 um 02:46 schrieb Richard Henderson:

> We do not need or want to be allocating page sized quanta.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> Cc: Stefan Weil <sw@weilnetz.de>
> ---
>  util/oslib-win32.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> index c654dafd93..8d838bf342 100644
> --- a/util/oslib-win32.c
> +++ b/util/oslib-win32.c
> @@ -56,10 +56,8 @@ void *qemu_try_memalign(size_t alignment, size_t size)
>  {
>      void *ptr;
>  
> -    if (!size) {
> -        abort();
> -    }
> -    ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
> +    assert(size != 0);
> +    ptr = _aligned_malloc(alignment, size);
>      trace_qemu_memalign(alignment, size, ptr);
>      return ptr;
>  }
> @@ -93,9 +91,7 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared)
>  void qemu_vfree(void *ptr)
>  {
>      trace_qemu_vfree(ptr);
> -    if (ptr) {
> -        VirtualFree(ptr, 0, MEM_RELEASE);
> -    }
> +    _aligned_free(ptr);
>  }
>  
>  void qemu_anon_ram_free(void *ptr, size_t size)


According to the documentation, malloc.h should be included for
_aligned_malloc. See
https://docs.microsoft.com/de-de/cpp/c-runtime-library/reference/aligned-malloc?view=vs-2019

I'd also use g_assert instead of assert to make sure that it is not
removed by NDEBUG.

Thanks,

Stefan

Re: [PATCH v2 1/6] util/oslib-win32: Use _aligned_malloc for qemu_try_memalign

[Eduardo Habkost]

On Tue, Sep 15, 2020 at 05:46:33PM -0700, Richard Henderson wrote:
> We do not need or want to be allocating page sized quanta.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Would it be safe to keep patches 2-6 applied in case this one
gets dropped or reverted for any reason?

I consider patches 2-6 bug fixes (that I'd like to merge soon),
and this one as an optimization (that could be merged later).

> ---
> Cc: Stefan Weil <sw@weilnetz.de>
> ---
>  util/oslib-win32.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> index c654dafd93..8d838bf342 100644
> --- a/util/oslib-win32.c
> +++ b/util/oslib-win32.c
> @@ -56,10 +56,8 @@ void *qemu_try_memalign(size_t alignment, size_t size)
>  {
>      void *ptr;
>  
> -    if (!size) {
> -        abort();
> -    }
> -    ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
> +    assert(size != 0);
> +    ptr = _aligned_malloc(alignment, size);
>      trace_qemu_memalign(alignment, size, ptr);
>      return ptr;
>  }
> @@ -93,9 +91,7 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared)
>  void qemu_vfree(void *ptr)
>  {
>      trace_qemu_vfree(ptr);
> -    if (ptr) {
> -        VirtualFree(ptr, 0, MEM_RELEASE);
> -    }
> +    _aligned_free(ptr);
>  }
>  
>  void qemu_anon_ram_free(void *ptr, size_t size)
> -- 
> 2.25.1
> 
> 

-- 
Eduardo

Re: [PATCH v2 1/6] util/oslib-win32: Use _aligned_malloc for qemu_try_memalign

[Richard Henderson]

On 9/17/20 11:43 AM, Eduardo Habkost wrote:
> On Tue, Sep 15, 2020 at 05:46:33PM -0700, Richard Henderson wrote:
>> We do not need or want to be allocating page sized quanta.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> 
> Would it be safe to keep patches 2-6 applied in case this one
> gets dropped or reverted for any reason?

Yes.

Only objects using QEMU_ALIGNED() should have an __alignof__ larger than
qemu_max_align_t.

Therefore, I believe that the CPUArchState objects to be the only ones that
will go through qemu_memalign.  So we won't end up with all QOM objects being
page allocated on Windows.


r~

[PATCH v2 2/6] qom: Allow objects to be allocated with increased alignment

[Richard Henderson]

It turns out that some hosts have a default malloc alignment less
than that required for vectors.

We assume that, with compiler annotation on CPUArchState, that we
can properly align the vector portion of the guest state.  Fix the
alignment of the allocation by using qemu_memalloc when required.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
---
 include/qom/object.h |  5 +++++
 qom/object.c         | 36 +++++++++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/qom/object.h b/include/qom/object.h
index 056f67ab3b..5709c36859 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -691,6 +691,7 @@ struct Object
         .parent = TYPE_##PARENT_MODULE_OBJ_NAME, \
         .name = TYPE_##MODULE_OBJ_NAME, \
         .instance_size = sizeof(ModuleObjName), \
+        .instance_align = __alignof__(ModuleObjName), \
         .instance_init = module_obj_name##_init, \
         .instance_finalize = module_obj_name##_finalize, \
         .class_size = sizeof(ModuleObjName##Class), \
@@ -770,6 +771,9 @@ struct Object
  * @instance_size: The size of the object (derivative of #Object).  If
  *   @instance_size is 0, then the size of the object will be the size of the
  *   parent object.
+ * @instance_align: The required alignment of the object.  If @instance_align
+ *   is 0, then normal malloc alignment is sufficient; if non-zero, then we
+ *   must use qemu_memalign for allocation.
  * @instance_init: This function is called to initialize an object.  The parent
  *   class will have already been initialized so the type is only responsible
  *   for initializing its own members.
@@ -807,6 +811,7 @@ struct TypeInfo
     const char *parent;
 
     size_t instance_size;
+    size_t instance_align;
     void (*instance_init)(Object *obj);
     void (*instance_post_init)(Object *obj);
     void (*instance_finalize)(Object *obj);
diff --git a/qom/object.c b/qom/object.c
index 387efb25eb..fcc15f6d88 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -50,6 +50,7 @@ struct TypeImpl
     size_t class_size;
 
     size_t instance_size;
+    size_t instance_align;
 
     void (*class_init)(ObjectClass *klass, void *data);
     void (*class_base_init)(ObjectClass *klass, void *data);
@@ -114,6 +115,7 @@ static TypeImpl *type_new(const TypeInfo *info)
 
     ti->class_size = info->class_size;
     ti->instance_size = info->instance_size;
+    ti->instance_align = info->instance_align;
 
     ti->class_init = info->class_init;
     ti->class_base_init = info->class_base_init;
@@ -688,16 +690,44 @@ static void object_finalize(void *data)
     }
 }
 
+/* Find the minimum alignment guaranteed by the system malloc. */
+#if __STDC_VERSION__ >= 201112L
+typddef max_align_t qemu_max_align_t;
+#else
+typedef union {
+    long l;
+    void *p;
+    double d;
+    long double ld;
+} qemu_max_align_t;
+#endif
+
 static Object *object_new_with_type(Type type)
 {
     Object *obj;
+    size_t size, align;
+    void (*obj_free)(void *);
 
     g_assert(type != NULL);
     type_initialize(type);
 
-    obj = g_malloc(type->instance_size);
-    object_initialize_with_type(obj, type->instance_size, type);
-    obj->free = g_free;
+    size = type->instance_size;
+    align = type->instance_align;
+
+    /*
+     * Do not use qemu_memalign unless required.  Depending on the
+     * implementation, extra alignment implies extra overhead.
+     */
+    if (likely(align <= __alignof__(qemu_max_align_t))) {
+        obj = g_malloc(size);
+        obj_free = g_free;
+    } else {
+        obj = qemu_memalign(align, size);
+        obj_free = qemu_vfree;
+    }
+
+    object_initialize_with_type(obj, size, type);
+    obj->free = obj_free;
 
     return obj;
 }
-- 
2.25.1

[PATCH v2 3/6] target/arm: Set instance_align on CPUARM TypeInfo

[Richard Henderson]

Fix alignment of CPUARMState.vfp.zregs.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
---
 target/arm/cpu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 7b5ea65fab..a7643deab4 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2290,6 +2290,7 @@ void arm_cpu_register(const ARMCPUInfo *info)
     TypeInfo type_info = {
         .parent = TYPE_ARM_CPU,
         .instance_size = sizeof(ARMCPU),
+        .instance_align = __alignof__(ARMCPU),
         .instance_init = arm_cpu_instance_init,
         .class_size = sizeof(ARMCPUClass),
         .class_init = info->class_init ?: cpu_register_class_init,
@@ -2305,6 +2306,7 @@ static const TypeInfo arm_cpu_type_info = {
     .name = TYPE_ARM_CPU,
     .parent = TYPE_CPU,
     .instance_size = sizeof(ARMCPU),
+    .instance_align = __alignof__(ARMCPU),
     .instance_init = arm_cpu_initfn,
     .instance_finalize = arm_cpu_finalizefn,
     .abstract = true,
-- 
2.25.1

[PATCH v2 4/6] target/ppc: Set instance_align on PowerPCCPU TypeInfo

[Richard Henderson]

Fix alignment of CPUPPCState.vsr.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-ppc@nongnu.org
---
 target/ppc/translate_init.c.inc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
index 230a062d29..accb4f2fae 100644
--- a/target/ppc/translate_init.c.inc
+++ b/target/ppc/translate_init.c.inc
@@ -10960,6 +10960,7 @@ static const TypeInfo ppc_cpu_type_info = {
     .name = TYPE_POWERPC_CPU,
     .parent = TYPE_CPU,
     .instance_size = sizeof(PowerPCCPU),
+    .instance_align = __alignof__(PowerPCCPU),
     .instance_init = ppc_cpu_instance_init,
     .instance_finalize = ppc_cpu_instance_finalize,
     .abstract = true,
-- 
2.25.1

Re: [PATCH v2 4/6] target/ppc: Set instance_align on PowerPCCPU TypeInfo

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 1172 bytes --]

On Tue, Sep 15, 2020 at 05:46:36PM -0700, Richard Henderson wrote:
> Fix alignment of CPUPPCState.vsr.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

LGTM

Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> Cc: David Gibson <david@gibson.dropbear.id.au>
> Cc: qemu-ppc@nongnu.org
> ---
>  target/ppc/translate_init.c.inc | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
> index 230a062d29..accb4f2fae 100644
> --- a/target/ppc/translate_init.c.inc
> +++ b/target/ppc/translate_init.c.inc
> @@ -10960,6 +10960,7 @@ static const TypeInfo ppc_cpu_type_info = {
>      .name = TYPE_POWERPC_CPU,
>      .parent = TYPE_CPU,
>      .instance_size = sizeof(PowerPCCPU),
> +    .instance_align = __alignof__(PowerPCCPU),
>      .instance_init = ppc_cpu_instance_init,
>      .instance_finalize = ppc_cpu_instance_finalize,
>      .abstract = true,

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[PATCH v2 5/6] target/riscv: Set instance_align on RISCVCPU TypeInfo

[Richard Henderson]

Fix alignment of CPURISCVState.vreg.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Cc: qemu-riscv@nongnu.org
---
 target/riscv/cpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 57c006df5d..0bbfd7f457 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -628,6 +628,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
         .name = TYPE_RISCV_CPU,
         .parent = TYPE_CPU,
         .instance_size = sizeof(RISCVCPU),
+        .instance_align = __alignof__(RISCVCPU),
         .instance_init = riscv_cpu_init,
         .abstract = true,
         .class_size = sizeof(RISCVCPUClass),
-- 
2.25.1

[PATCH v2 5/6] target/riscv: Set instance_align on RISCVCPU TypeInfo

[Richard Henderson]

Fix alignment of CPURISCVState.vreg.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Cc: qemu-riscv@nongnu.org
---
 target/riscv/cpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 57c006df5d..0bbfd7f457 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -628,6 +628,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
         .name = TYPE_RISCV_CPU,
         .parent = TYPE_CPU,
         .instance_size = sizeof(RISCVCPU),
+        .instance_align = __alignof__(RISCVCPU),
         .instance_init = riscv_cpu_init,
         .abstract = true,
         .class_size = sizeof(RISCVCPUClass),
-- 
2.25.1

Re: [PATCH v2 5/6] target/riscv: Set instance_align on RISCVCPU TypeInfo

[Alistair Francis]

On Tue, Sep 15, 2020 at 5:47 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Fix alignment of CPURISCVState.vreg.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
> Cc: Alistair Francis <Alistair.Francis@wdc.com>
> Cc: qemu-riscv@nongnu.org
> ---
>  target/riscv/cpu.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 57c006df5d..0bbfd7f457 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -628,6 +628,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>          .name = TYPE_RISCV_CPU,
>          .parent = TYPE_CPU,
>          .instance_size = sizeof(RISCVCPU),
> +        .instance_align = __alignof__(RISCVCPU),
>          .instance_init = riscv_cpu_init,
>          .abstract = true,
>          .class_size = sizeof(RISCVCPUClass),
> --
> 2.25.1
>
>

Re: [PATCH v2 5/6] target/riscv: Set instance_align on RISCVCPU TypeInfo

[Alistair Francis]

On Tue, Sep 15, 2020 at 5:47 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Fix alignment of CPURISCVState.vreg.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
> Cc: Alistair Francis <Alistair.Francis@wdc.com>
> Cc: qemu-riscv@nongnu.org
> ---
>  target/riscv/cpu.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 57c006df5d..0bbfd7f457 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -628,6 +628,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>          .name = TYPE_RISCV_CPU,
>          .parent = TYPE_CPU,
>          .instance_size = sizeof(RISCVCPU),
> +        .instance_align = __alignof__(RISCVCPU),
>          .instance_init = riscv_cpu_init,
>          .abstract = true,
>          .class_size = sizeof(RISCVCPUClass),
> --
> 2.25.1
>
>

[PATCH v2 6/6] target/s390x: Set instance_align on S390CPU TypeInfo

[Richard Henderson]

Fix alignment of CPUS390XState.vregs.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: qemu-s390x@nongnu.org
---
 target/s390x/cpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 749cd548f0..e350edc9f5 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -517,6 +517,7 @@ static const TypeInfo s390_cpu_type_info = {
     .name = TYPE_S390_CPU,
     .parent = TYPE_CPU,
     .instance_size = sizeof(S390CPU),
+    .instance_align = __alignof__(S390CPU),
     .instance_init = s390_cpu_initfn,
     .instance_finalize = s390_cpu_finalize,
     .abstract = true,
-- 
2.25.1

Re: [PATCH v2 0/6] qom: Allow object to be aligned

[Eduardo Habkost]

On Tue, Sep 15, 2020 at 05:46:32PM -0700, Richard Henderson wrote:
> I've seen some failures on arm and s390x hosts after
> enabling host vector support.  It turns out that the
> malloc for these hosts does not provide 16-byte alignment.
> 
> We already have a function that can alloc with alignment,
> but we need to pass this down from the structure.  We also
> don't want to use this function unconditionally, because
> the windows version does page allocation, which would be
> overkill for the vast majority of the objects allocated.

I'm queueing patches 2-6.  Thanks!

-- 
Eduardo

Re: [PATCH v2 0/6] qom: Allow object to be aligned

[Eduardo Habkost]

On Tue, Sep 15, 2020 at 05:46:32PM -0700, Richard Henderson wrote:
> I've seen some failures on arm and s390x hosts after
> enabling host vector support.  It turns out that the
> malloc for these hosts does not provide 16-byte alignment.
> 
> We already have a function that can alloc with alignment,
> but we need to pass this down from the structure.  We also
> don't want to use this function unconditionally, because
> the windows version does page allocation, which would be
> overkill for the vast majority of the objects allocated.

I'm queueing patches 2-6.  Thanks!

-- 
Eduardo