On Wed, May 19, 2021 at 10:22:48PM +0200, Alexander Graf wrote:
> From: Peter Collingbourne <pcc@google.com>
> 
> Sleep on WFI until the VTIMER is due but allow ourselves to be woken
> up on IPI.
> 
> In this implementation IPI is blocked on the CPU thread at startup and
> pselect() is used to atomically unblock the signal and begin sleeping.
> The signal is sent unconditionally so there's no need to worry about
> races between actually sleeping and the "we think we're sleeping"
> state. It may lead to an extra wakeup but that's better than missing
> it entirely.
> 
> Signed-off-by: Peter Collingbourne <pcc@google.com>
> [agraf: Remove unused 'set' variable, always advance PC on WFX trap]
> Signed-off-by: Alexander Graf <agraf@csgraf.de>
> Acked-by: Roman Bolshakov <r.bolshakov@yadro.com>
> 
> ---
> 
> v6 -> v7:
> 
>   - Move WFI into function
>   - Improve comment wording
> ---
>  accel/hvf/hvf-accel-ops.c |  5 ++-
>  include/sysemu/hvf_int.h  |  1 +
>  target/arm/hvf/hvf.c      | 68 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 71 insertions(+), 3 deletions(-)

Reviewed-by: Sergio Lopez <slp@redhat.com>