From patchwork Mon Sep 3 00:58:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 181278 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 52A972C0084 for ; Mon, 3 Sep 2012 10:58:25 +1000 (EST) Received: from localhost ([::1]:48710 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T8Kzf-0004bn-CE for incoming@patchwork.ozlabs.org; Sun, 02 Sep 2012 20:58:23 -0400 Received: from eggs.gnu.org ([208.118.235.92]:35111) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T8KzZ-0004bi-Ac for qemu-devel@nongnu.org; Sun, 02 Sep 2012 20:58:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T8KzY-0006Qe-1e for qemu-devel@nongnu.org; Sun, 02 Sep 2012 20:58:17 -0400 Received: from ozlabs.org ([203.10.76.45]:55339) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T8KzX-0006QT-MO for qemu-devel@nongnu.org; Sun, 02 Sep 2012 20:58:15 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 49F9A2C0094; Mon, 3 Sep 2012 10:58:10 +1000 (EST) From: David Gibson To: aliguori@us.ibm.com, qemu-devel@nongnu.org Date: Mon, 3 Sep 2012 10:58:28 +1000 Message-Id: <1346633908-31386-1-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 1.7.10.4 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 203.10.76.45 Cc: agraf@suse.de, David Gibson Subject: [Qemu-devel] [PATCH] cpu_physical_memory_write_rom() needs to do TB invalidates X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org cpu_physical_memory_write_rom(), despite the name, can also be used to write images into RAM - and will often be used that way if the machine uses load_image_targphys() into RAM addresses. However, cpu_physical_memory_write_rom(), unlike cpu_physical_memory_rw() doesn't invalidate any cached TBs which might be affected by the region written. This was breaking reset (under full emu) on the pseries machine - we loaded our firmware image into RAM, and while executing it rewrite the code at the entry point (correctly causing a TB invalidate/refresh). When we reset the firmware image was reloaded, but the TB from the rewrite was still active and caused us to get an illegal instruction trap. This patch fixes the bug by duplicating the tb invalidate code from cpu_physical_memory_rw() in cpu_physical_memory_write_rom(). Signed-off-by: David Gibson --- exec.c | 7 +++++++ 1 file changed, 7 insertions(+) I've sent this before, and there was some discussion about the details, but as far as I can tell the conclusion was that this patch was as good as any, at least for fixing the existing bug in 1.2 / stable. However, it still hasn't been merged. Please apply for stable as well as mainline. diff --git a/exec.c b/exec.c index 5834766..eff40d7 100644 --- a/exec.c +++ b/exec.c @@ -3523,6 +3523,13 @@ void cpu_physical_memory_write_rom(target_phys_addr_t addr, /* ROM/RAM case */ ptr = qemu_get_ram_ptr(addr1); memcpy(ptr, buf, l); + if (!cpu_physical_memory_is_dirty(addr1)) { + /* invalidate code */ + tb_invalidate_phys_page_range(addr1, addr1 + l, 0); + /* set dirty bit */ + cpu_physical_memory_set_dirty_flags( + addr1, (0xff & ~CODE_DIRTY_FLAG)); + } qemu_put_ram_ptr(ptr); } len -= l;