Re: [PATCH v4 2/2] xen/vm-events: Move parts of monitor_domctl code to common-side.

[Corneliu ZUZU <czuzu@bitdefender.com>]

On 2/16/2016 9:08 AM, Corneliu ZUZU wrote:
> This patch moves monitor_domctl to common-side.
> Purpose: move what's common to common, prepare for implementation
> of such vm-events on ARM.
>
> * move get_capabilities to arch-side => arch_monitor_get_capabilities.
> * add arch-side monitor op handling function => arch_monitor_domctl_op.
>    e.g. X86-side handles XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP op
> * add arch-side monitor event handling function => arch_monitor_domctl_event.
>    e.g. X86-side handles XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR event enable/disable
> * remove status_check
>
> Signed-off-by: Corneliu ZUZU <czuzu@bitdefender.com>
>
> ---
> Changed since v3:
>    * monitor_domctl @ common/monitor.c:
>      - remove unused requested_status
>      - sanity check mop->event range to avoid left-shift undefined behavior

Due to left-shift undefined behavior situations, shouldn't I also:

* in X86 arch_monitor_get_capabilities: replace '1 <<' w/ '1U <<'

* in X86 arch_monitor_domctl_event, 
XEN_DOMCTL_MONITOR_EVENT_WRITE_CTRLREG case
add a sanity check of mop->u.mov_to_cr.index before:
     unsigned int ctrlreg_bitmask = 
monitor_ctrlreg_bitmask(mop->u.mov_to_cr.index);
, which basically translates to:
     unsigned int ctrlreg_bitmask = (1U << mop->u.mov_to_cr.index);

? (especially since mop->u.mov_to_cr.index is set by the caller).

Would have been good if I'd thought of that before sending this patch 
series :).

Thanks,
Corneliu.