* enable notdirty_write for snapshots when possible
Snapshots only happens when the priority of the memory region is smaller
then the snapshot_level. After a snapshot notdirty can be set.
* disable notdirty_write for self modifying code
When SMC access the memory region more then once the
tb must be rebuild multible times.
fixes#2029
* notdirty_write better hook check
Check all relevant memory hooks before enabling notdirty write.
This also checks if the memory hook is registered for the affected
region. So it is possible to use notdirty write and have some hooks
on different addresses.
* notdirty_write check for addr_write in snapshot case
* self modifying code clear recursive mem access
when self modifying code does unaligned memory accese sometimes
uc->size_recur_mem is changed but for notdirty write not changed back.
This causes mem_hooks to be missed. To fix this uc->size_recur_mem is
set to 0 before each cpu_exec() call.
* optimize ram block handling
Save the last element of the ram_list. This allows to
faster find where to add new elements when they are not
bigger then page size.
* save ram_list freed
this keeps the optimization for find_ram_offset() intact after snapshot
restore.
* cow only clear the tlb of affected pages
* update flatview when possible
Building each flatview new when the memory has changed is quite
expensive when many MemoryRegions are used. This is an issue when using
snapshots.
* update benchmark for new api
* save flatview in context
this avoids rebuilding the flatview when restore a context.
* init context flatview with zero
* address_space_dispatch_clear remove subpage with higher priority
* docutemnt the options for UC_CTL_CONTEXT_MODE
Specialy stress that with UC_CTL_CONTEXT_MEMORY it is not possible to
use the context with a different unicorn object.
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>
Uses Copy on Write to make it posible to restore the memory state after a snapshot
was made. To restore all MemoryRegions created after the snapshot are removed.
Consider this case:
t:inc ecx,
inc edx,
jmp t
It would generate exactly one block and TB chain will generate an inline
jump. If we don't check exit at the entry of the block, we will never be
terminated.
This test case is recorded in the commit message since it's a bit
painful to write multithread related code that builds on all platforms.
When unicorn and systemd are combined into a single binary the 2
libraries conflict on bitmap_set and bitmap_clear functions which breaks
unicorn.
Co-authored-by: Nicolae Mogoreanu <mogo@google.com>
