From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57832) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fKuOt-0002eK-6s for qemu-devel@nongnu.org; Mon, 21 May 2018 19:39:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fKuOq-0005Y3-Fl for qemu-devel@nongnu.org; Mon, 21 May 2018 19:39:35 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:57707) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fKuOq-0005We-6T for qemu-devel@nongnu.org; Mon, 21 May 2018 19:39:32 -0400 From: "Emilio G. Cota" Date: Mon, 21 May 2018 19:39:18 -0400 Message-Id: <1526945967-9687-9-git-send-email-cota@braap.org> In-Reply-To: <1526945967-9687-1-git-send-email-cota@braap.org> References: <1526945967-9687-1-git-send-email-cota@braap.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH v3 08/17] 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: Richard Henderson , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Paolo Bonzini 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 --- 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 07674e4..8622f25 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); } } -- 2.7.4