From patchwork Wed Feb 7 12:03:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10205029 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CE36E602D8 for ; Wed, 7 Feb 2018 12:05:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A61FE28F24 for ; Wed, 7 Feb 2018 12:05:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A83528F29; Wed, 7 Feb 2018 12:05:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 52C5328F24 for ; Wed, 7 Feb 2018 12:05:44 +0000 (UTC) Received: from localhost ([::1]:56764 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTv-0001PK-Hi for patchwork-qemu-devel@patchwork.kernel.org; Wed, 07 Feb 2018 07:05:43 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49868) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOSF-0008DN-3p for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:04:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejOSD-0003Vs-Sb for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:03:59 -0500 Received: from mail.ispras.ru ([83.149.199.45]:47268) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOSD-0003V1-KP for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:03:57 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id A563254008C; Wed, 7 Feb 2018 15:03:56 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 07 Feb 2018 15:03:59 +0300 Message-ID: <20180207120358.5389.88216.stgit@pasha-VirtualBox> In-Reply-To: <20180207120353.5389.54531.stgit@pasha-VirtualBox> References: <20180207120353.5389.54531.stgit@pasha-VirtualBox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [RFC PATCH v6 01/20] cpu-exec: fix exception_index handling X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, pavel.dovgaluk@ispras.ru, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, mst@redhat.com, zuban32s@gmail.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Function cpu_handle_interrupt calls cc->cpu_exec_interrupt to process pending hardware interrupts. Under the hood cpu_exec_interrupt uses cpu->exception_index to pass information to the internal function which is usually common for exception and interrupt processing. But this value is not reset after return and may be processed again by cpu_handle_exception. This does not happen due to overwriting the exception_index at the end of cpu_handle_interrupt. But this branch may also overwrite the valid exception_index in some cases. Therefore this patch: 1. resets exception_index just after the call to cpu_exec_interrupt 2. prevents overwriting the meaningful value of exception_index Signed-off-by: Pavel Dovgalyuk Signed-off-by: Paolo Bonzini --- accel/tcg/cpu-exec.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 280200f..9cc6972 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -585,6 +585,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, else { if (cc->cpu_exec_interrupt(cpu, interrupt_request)) { replay_interrupt(); + cpu->exception_index = -1; *last_tb = NULL; } /* The target hook may have updated the 'cpu->interrupt_request'; @@ -606,7 +607,9 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, if (unlikely(atomic_read(&cpu->exit_request) || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra == 0))) { atomic_set(&cpu->exit_request, 0); - cpu->exception_index = EXCP_INTERRUPT; + if (cpu->exception_index == -1) { + cpu->exception_index = EXCP_INTERRUPT; + } return true; }