Re: [XEN v3 03/12] xen/Arm: vreg: Support vreg_reg64_* helpers on AArch32

[Julien Grall <julien@xxxxxxx>]

Hi Michal,

On 17/11/2022 13:11, Michal Orzel wrote:
> On 11/11/2022 15:17, Ayan Kumar Halder wrote:
> > In some situations (e.g. GICR_TYPER), the hypervior may need to emulate
> > 64bit registers in AArch32 mode. In such situations, the hypervisor may
> > need to read/modify the lower or upper 32 bits of the 64 bit register.
> >
> > In AArch32, 'unsigned long' is 32 bits. Thus, we cannot use it for 64 bit
> > registers.
> >
> > While we could replace 'unsigned long' by 'uint64_t', it is not entirely clear
> > whether a 32-bit compiler would not allocate register for the upper 32-bit.
> > Therefore fold vreg_reg_* helper in the size specific one and use the
> > appropriate type based on the size requested.
> >
> > Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
Acked-by: Julien Grall <julien@xxxxxxx>

Cheers,

--
Julien Grall