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[Qemu-devel] [PULL 09/18] translate-all: work page-by-page in tb_invalid
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL 09/18] translate-all: work page-by-page in tb_invalidate_phys_range_1 |
Date: |
Thu, 14 Jun 2018 09:31:38 -1000 |
From: "Emilio G. Cota" <address@hidden>
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 <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Emilio G. Cota <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
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 b9c36a3e45..f32904d4a3 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -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);
}
}
--
2.17.1
- [Qemu-devel] [PULL 00/18] tcg queued patches, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 01/18] tcg/i386: Use byte form of xgetbv instruction, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 03/18] qht: return existing entry when qht_insert fails, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 02/18] qht: require a default comparison function, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 04/18] tcg: track TBs with per-region BST's, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 06/18] translate-all: iterate over TBs in a page with PAGE_FOR_EACH_TB, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 05/18] tcg: move tb_ctx.tb_phys_invalidate_count to tcg_ctx, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 07/18] translate-all: make l1_map lockless, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 09/18] translate-all: work page-by-page in tb_invalidate_phys_range_1,
Richard Henderson <=
- [Qemu-devel] [PULL 08/18] translate-all: remove hole in PageDesc, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 10/18] translate-all: move tb_invalidate_phys_page_range up in the file, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 11/18] translate-all: use per-page locking in !user-mode, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 13/18] translate-all: introduce assert_no_pages_locked, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 12/18] translate-all: add page_locked assertions, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 14/18] translate-all: discard TB when tb_link_page returns an existing matching TB, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 15/18] translate-all: protect TB jumps with a per-destination-TB lock, Richard Henderson, 2018/06/14
- [Qemu-devel] [PULL 16/18] cputlb: remove tb_lock from tlb_flush functions, Richard Henderson, 2018/06/14