[PATCH] vfio: use matching sizeof type

Paolo Bonzini posted 1 patch 8 months, 1 week ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20240117160344.175872-1-pbonzini@redhat.com
Maintainers: Alex Williamson <alex.williamson@redhat.com>, "Cédric Le Goater" <clg@redhat.com>
hw/vfio/common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] vfio: use matching sizeof type
Posted by Paolo Bonzini 8 months, 1 week ago
Do not use uint64_t for the type of the declaration and __u64 when
computing the number of elements in the array.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/vfio/common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 0b3352f2a9d..0da4003ecf5 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1118,7 +1118,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
 {
     uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
                         sizeof(struct vfio_device_feature_dma_logging_report),
-                        sizeof(__u64))] = {};
+                        sizeof(uint64_t))] = {};
     struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
     struct vfio_device_feature_dma_logging_report *report =
         (struct vfio_device_feature_dma_logging_report *)feature->data;
-- 
2.43.0
Re: [PATCH] vfio: use matching sizeof type
Posted by Peter Xu 8 months ago
On Wed, Jan 17, 2024 at 05:03:44PM +0100, Paolo Bonzini wrote:
> Do not use uint64_t for the type of the declaration and __u64 when
> computing the number of elements in the array.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/vfio/common.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 0b3352f2a9d..0da4003ecf5 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1118,7 +1118,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
>  {
>      uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
>                          sizeof(struct vfio_device_feature_dma_logging_report),
> -                        sizeof(__u64))] = {};
> +                        sizeof(uint64_t))] = {};
>      struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
>      struct vfio_device_feature_dma_logging_report *report =
>          (struct vfio_device_feature_dma_logging_report *)feature->data;

There seem to have other places in the sme file that reference __u64.  Are
we going to remove all __u64 references?  Or maybe something else?

Copy Alex/Cedric to make sure this won't get lost..

Thanks,

-- 
Peter Xu
Re: [PATCH] vfio: use matching sizeof type
Posted by Paolo Bonzini 8 months ago
Il gio 18 gen 2024, 06:09 Peter Xu <peterx@redhat.com> ha scritto:

> On Wed, Jan 17, 2024 at 05:03:44PM +0100, Paolo Bonzini wrote:
> > Do not use uint64_t for the type of the declaration and __u64 when
> > computing the number of elements in the array.
> >
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >  hw/vfio/common.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> > index 0b3352f2a9d..0da4003ecf5 100644
> > --- a/hw/vfio/common.c
> > +++ b/hw/vfio/common.c
> > @@ -1118,7 +1118,7 @@ static int
> vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
> >  {
> >      uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
> >                          sizeof(struct
> vfio_device_feature_dma_logging_report),
> > -                        sizeof(__u64))] = {};
> > +                        sizeof(uint64_t))] = {};
> >      struct vfio_device_feature *feature = (struct vfio_device_feature
> *)buf;
> >      struct vfio_device_feature_dma_logging_report *report =
> >          (struct vfio_device_feature_dma_logging_report *)feature->data;
>
> There seem to have other places in the sme file that reference __u64.  Are
> we going to remove all __u64 references?  Or maybe something else?
>

I wanted to remove those that are unnecessary, but in some cases you have
to keep __u64, because you don't know that __u64 and uint64_t are the same
type (so e.g. they could have incompatible pointer types and printf
specifiers).

Paolo


> Copy Alex/Cedric to make sure this won't get lost..
>
> Thanks,
>
> --
> Peter Xu
>
>
Re: [PATCH] vfio: use matching sizeof type
Posted by Cédric Le Goater 8 months ago
On 1/18/24 06:09, Peter Xu wrote:
> On Wed, Jan 17, 2024 at 05:03:44PM +0100, Paolo Bonzini wrote:
>> Do not use uint64_t for the type of the declaration and __u64 when
>> computing the number of elements in the array.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>   hw/vfio/common.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 0b3352f2a9d..0da4003ecf5 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -1118,7 +1118,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
>>   {
>>       uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
>>                           sizeof(struct vfio_device_feature_dma_logging_report),
>> -                        sizeof(__u64))] = {};
>> +                        sizeof(uint64_t))] = {};
>>       struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
>>       struct vfio_device_feature_dma_logging_report *report =
>>           (struct vfio_device_feature_dma_logging_report *)feature->data;
> 
> There seem to have other places in the sme file that reference __u64.  Are
> we going to remove all __u64 references?  Or maybe something else?

AFAIUI, this change is to match the types of the 'buf' array and
the one used by sizeof.
  
> Copy Alex/Cedric to make sure this won't get lost..

Applied to vfio-next.

Thanks,

C.
Re: [PATCH] vfio: use matching sizeof type
Posted by Philippe Mathieu-Daudé 8 months, 1 week ago
On 17/1/24 17:03, Paolo Bonzini wrote:
> Do not use uint64_t for the type of the declaration and __u64 when
> computing the number of elements in the array.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   hw/vfio/common.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>