On 04/29/2015 05:21 AM, Paolo Bonzini wrote:
> guest_enter and guest_exit must be called with interrupts disabled,
> since they take the vtime_seqlock with write_seq{lock,unlock}.
> Therefore, it is not necessary to check for exceptions, nor to
> save/restore the IRQ state, when context tracking functions are
> called by guest_enter and guest_exit.
>
> Split the body of context_tracking_entry and context_tracking_exit
> out to __-prefixed functions, and use them from KVM.
>
> Rik van Riel has measured this to speed up a tight vmentry/vmexit
> loop by about 2%.
>
> Cc: Frederic Weisbecker <[email protected]>
> Cc: Rik van Riel <[email protected]>
> Cc: Paul McKenney <[email protected]>
> Signed-off-by: Paolo Bonzini <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Tested-by: Rik van Riel <[email protected]>
... now time to figure out the same thing for user_enter
and/or user_exit, lets see which of those we can call
with irqs already disabled :)
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