kvm/vfio: avoid bouncing the mutex when adding and deleting groups

Stop taking kv->lock mutex in kvm_vfio_update_coherency() and instead
call it with this mutex held: the callers of the function usually
already have it taken (and released) before calling
kvm_vfio_update_coherency(). This avoid bouncing the lock up and down.

The exception is kvm_vfio_release() where we do not take the lock, but
it is being executed when the very last reference to kvm_device is being
dropped, so there are no concerns about concurrency.

Suggested-by: Alex Williamson <[email protected]>
Reviewed-by: Alex Williamson <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

0 files changed, 0 insertions, 0 deletions