29.06.2023 11:25, Mark Cave-Ayland wrote:
Add an assert() check in tb_invalidate_phys_page_range__locked() to ensure that
both the start and last addresses are within the same target page. Note that
due to performance concerns the check is only enabled when QEMU is configured
with --enable-debug-tcg.

Performance concerns? That's two ANDs and on compare, - is it really that 
performance
critical?

I'm just asking, I dunno.

Thanks,

/mjt

Signed-off-by: Mark Cave-Ayland <[email protected]>
---
  accel/tcg/tb-maint.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c
index 33ea1aadd1..8cd730dcb0 100644
--- a/accel/tcg/tb-maint.c
+++ b/accel/tcg/tb-maint.c
@@ -1092,6 +1092,10 @@ tb_invalidate_phys_page_range__locked(struct 
page_collection *pages,
      TranslationBlock *current_tb = retaddr ? tcg_tb_lookup(retaddr) : NULL;
  #endif /* TARGET_HAS_PRECISE_SMC */
+#ifdef CONFIG_DEBUG_TCG
+    assert((last & TARGET_PAGE_MASK) == (start & TARGET_PAGE_MASK));
+#endif
+
      /*
       * We remove all the TBs in the range [start, last].
       * XXX: see if in some cases it could be faster to invalidate all the code


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