From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36975) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fTXyd-00071B-1o for qemu-devel@nongnu.org; Thu, 14 Jun 2018 15:32:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fTXyb-0005pU-Tc for qemu-devel@nongnu.org; Thu, 14 Jun 2018 15:32:10 -0400 Received: from mail-pg0-x232.google.com ([2607:f8b0:400e:c05::232]:44099) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fTXyb-0005ol-NG for qemu-devel@nongnu.org; Thu, 14 Jun 2018 15:32:09 -0400 Received: by mail-pg0-x232.google.com with SMTP id p21-v6so3354716pgd.11 for ; Thu, 14 Jun 2018 12:32:09 -0700 (PDT) From: Richard Henderson Date: Thu, 14 Jun 2018 09:31:38 -1000 Message-Id: <20180614193147.29680-10-richard.henderson@linaro.org> In-Reply-To: <20180614193147.29680-1-richard.henderson@linaro.org> References: <20180614193147.29680-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PULL 09/18] translate-all: work page-by-page in tb_invalidate_phys_range_1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, "Emilio G. Cota" From: "Emilio G. Cota" 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 Reviewed-by: Alex Bennée Signed-off-by: Emilio G. Cota Signed-off-by: Richard Henderson --- 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