diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/devel/multi-thread-tcg.txt | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/docs/devel/multi-thread-tcg.txt b/docs/devel/multi-thread-tcg.txt index df83445ccf..06530be1e9 100644 --- a/docs/devel/multi-thread-tcg.txt +++ b/docs/devel/multi-thread-tcg.txt @@ -61,6 +61,7 @@ have their block-to-block jumps patched. Global TCG State ---------------- +### User-mode emulation We need to protect the entire code generation cycle including any post generation patching of the translated code. This also implies a shared translation buffer which contains code running on all cores. Any @@ -75,9 +76,11 @@ patching. (Current solution) -Mainly as part of the linux-user work all code generation is -serialised with a tb_lock(). For the SoftMMU tb_lock() also takes the -place of mmap_lock() in linux-user. +Code generation is serialised with mmap_lock(). + +### !User-mode emulation +Each vCPU has its own TCG context and associated TCG region, thereby +requiring no locking. Translation Blocks ------------------ @@ -195,7 +198,7 @@ work as "safe work" and exiting the cpu run loop. This ensure by the time execution restarts all flush operations have completed. TLB flag updates are all done atomically and are also protected by the -tb_lock() which is used by the functions that update the TLB in bulk. +corresponding page lock. (Known limitation) |