Every store would always cause the tb_invalidate_phys_page_fast path to be invoked,
amounting to a 40x slowdown of stores compared to loads.
Change this code to only worry about TB invalidation for regions marked as
executable (i.e. emulated executable).
Even without uc_set_native_thunks, this change fixes most of the performance
issues seen with thunking to native calls.
Signed-off-by: Andrei Warkentin <andrei.warkentin@intel.com>
The wfi exception trigger behavior should take into account user mode,
hstatus.vtw, and the fact the an wfi might raise different types of
exceptions depending on various factors:
If supervisor mode is not present:
- an illegal instruction exception should be generated if user mode
executes and wfi instruction and mstatus.tw = 1.
If supervisor mode is present:
- when a wfi instruction is executed, an illegal exception should be triggered
if either the current mode is user or the mode is supervisor and mstatus.tw is
set.
Plus, if the hypervisor extensions are enabled:
- a virtual instruction exception should be raised when a wfi is executed from
virtual-user or virtual-supervisor and hstatus.vtw is set.
Signed-off-by: Jose Martins <josemartins90@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210420213656.85148-1-josemartins90@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
