Commit ae5486e2 authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

translate-all: work page-by-page in tb_invalidate_phys_range_1 

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: default avatarRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
parent 94da9aec

accel/tcg/translate-all.c

+8 −4
Original line number Diff line number Diff line
@@ -1375,10 +1375,14 @@ 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);

    }

}