Re: [Xen-devel] [PATCH] xen/x86: Remove unnecessary cast on void pointer

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

Thanks!

On Sat, Mar 28, 2020 at 11:08:35AM +0530, Simran Singhal wrote:
> diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
> index f049920196..a53d3ca2a4 100644
> --- a/xen/arch/x86/hvm/vmx/vvmx.c
> +++ b/xen/arch/x86/hvm/vmx/vvmx.c
> @@ -256,7 +256,7 @@ static int vvmcs_offset(u32 width, u32 type, u32 index)
>  u64 get_vvmcs_virtual(void *vvmcs, u32 vmcs_encoding)
>  {
>      union vmcs_encoding enc;
> -    u64 *content = (u64 *) vvmcs;
> +    u64 *content = vvmcs;
>      int offset;
>      u64 res;
>  
> @@ -310,7 +310,7 @@ enum vmx_insn_errno get_vvmcs_real_safe(const struct vcpu 
> *v, u32 encoding,
>  void set_vvmcs_virtual(void *vvmcs, u32 vmcs_encoding, u64 val)
>  {
>      union vmcs_encoding enc;
> -    u64 *content = (u64 *) vvmcs;
> +    u64 *content = vvmcs;

While there, would you mind changing u64 to uint64_t? (here and
above)

>      int offset;
>      u64 res;
>  
> diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
> index eb66077496..058b9b8adf 100644
> --- a/xen/arch/x86/mm/p2m-pt.c
> +++ b/xen/arch/x86/mm/p2m-pt.c
> @@ -127,7 +127,7 @@ p2m_find_entry(void *table, unsigned long *gfn_remainder,
>          return NULL;
>      }
>      *gfn_remainder &= (1 << shift) - 1;
> -    return (l1_pgentry_t *)table + index;
> +    return table + index;

I don't think removing this cast is correct, as you would be doing a
plain addition to a pointer instead of fetching the next entry in the
array of l1_pgentry_t entries.

If you want to get rid of the cast here you need to change the type of
the table parameter to l1_pgentry_t * instead of void *.

Thanks, Roger.