So that we pass a same-page range to tb_invalidate_phys_page_range, instead of always passing an end address that could be on a different page.
As discussed with Peter Maydell on the list [1], tb_invalidate_phys_page_range doesn't actually do much with 'end', which explains why we have never hit a bug despite going against what the comment on top of tb_invalidate_phys_page_range requires: > * Invalidate all TBs which intersect with the target physical address range > * [start;end[. NOTE: start and end must refer to the *same* physical page. The appended honours the comment, which avoids confusion. While at it, rework the loop into a for loop, which is less error prone (e.g. "continue" won't result in an infinite loop). [1] https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg09165.html Reviewed-by: Richard Henderson <richard.hender...@linaro.org> Reviewed-by: Alex Bennée <alex.ben...@linaro.org> Signed-off-by: Emilio G. Cota <c...@braap.org> --- accel/tcg/translate-all.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 7c72354..b27aacc 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1378,10 +1378,14 @@ TranslationBlock *tb_gen_code(CPUState *cpu, */ static void tb_invalidate_phys_range_1(tb_page_addr_t start, tb_page_addr_t end) { - while (start < end) { - tb_invalidate_phys_page_range(start, end, 0); - start &= TARGET_PAGE_MASK; - start += TARGET_PAGE_SIZE; + tb_page_addr_t next; + + for (next = (start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; + start < end; + start = next, next += TARGET_PAGE_SIZE) { + tb_page_addr_t bound = MIN(next, end); + + tb_invalidate_phys_page_range(start, bound, 0); } } -- 2.7.4
