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: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
master
Emilio G. Cota 2017-08-05 02:04:40 -04:00 committed by Richard Henderson
parent 94da9aec2a
commit ae5486e273
1 changed files with 8 additions and 4 deletions

View File

@ -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);
}
}