Re: [Xen-devel] [PATCH 3/5] xen/vm-event: Remove unnecessary vm_event_domain indirection

[Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>]

On 6/3/19 3:25 PM, Andrew Cooper wrote:
> The use of (*ved)-> leads to poor code generation, as the compiler can't
> assume the pointer hasn't changed, and results in hard-to-follow code.
>
> For both vm_event_{en,dis}able(), rename the ved parameter to p_ved, and
> work primarily with a local ved pointer.
>
> This has a key advantage in vm_event_enable(), in that the partially
> constructed vm_event_domain only becomes globally visible once it is
> fully constructed.  As a consequence, the spinlock doesn't need holding.
>
> Furthermore, rearrange the order of operations to be more sensible.
> Check for repeated enables and an bad HVM_PARAM before allocating
> memory, and gather the trivial setup into one place, dropping the
> redundant zeroing.
>
> No practical change that callers will notice.
>
> Signed-off-by: Andrew Cooper<andrew.cooper3@xxxxxxxxxx>
Acked-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>


Thanks,
Razvan

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