From patchwork Mon Dec 19 13:21:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 9480259 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 209BD601C0 for ; Mon, 19 Dec 2016 13:21:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 089AD28487 for ; Mon, 19 Dec 2016 13:21:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F07B5284C5; Mon, 19 Dec 2016 13:21:48 +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 494FA28487 for ; Mon, 19 Dec 2016 13:21:48 +0000 (UTC) Received: from localhost ([::1]:45396 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cIxsx-00079e-Eb for patchwork-qemu-devel@patchwork.kernel.org; Mon, 19 Dec 2016 08:21:47 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34145) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cIxsO-00076e-RY for qemu-devel@nongnu.org; Mon, 19 Dec 2016 08:21:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cIxsN-0007aS-Us for qemu-devel@nongnu.org; Mon, 19 Dec 2016 08:21:12 -0500 Received: from mail.ispras.ru ([83.149.199.45]:46250) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cIxsN-0007aD-Ng for qemu-devel@nongnu.org; Mon, 19 Dec 2016 08:21:11 -0500 Received: from [10.10.150.205] (unknown [85.142.117.224]) by mail.ispras.ru (Postfix) with ESMTPSA id 0E8F154006F; Mon, 19 Dec 2016 16:21:11 +0300 (MSK) To: qemu-devel@nongnu.org From: Pavel Dovgalyuk Date: Mon, 19 Dec 2016 16:21:11 +0300 Message-ID: <20161219132111.3016.50241.stgit@PASHA-ISP> In-Reply-To: <20161219132102.3016.46687.stgit@PASHA-ISP> References: <20161219132102.3016.46687.stgit@PASHA-ISP> User-Agent: StGit/0.16 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] [PATCH v6 1/9] icount: update instruction counter on apic patching 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, mst@redhat.com, jasowang@redhat.com, quintela@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP kvmvapic patches the code when some instructions are executed. E.g. mov 0xff, 0xfffe0080 is interpreted as push 0xff/call ... This patching is also followed by some side effects (changing apic and guest memory state). Therefore deterministic execution should take this operation into account. This patch decreases icount when original mov instruction is trying to execute. Therefore patching becomes deterministic and can be replayed correctly. Signed-off-by: Pavel Dovgalyuk --- hw/i386/kvmvapic.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c index b30d1b9..146d47c 100644 --- a/hw/i386/kvmvapic.c +++ b/hw/i386/kvmvapic.c @@ -412,6 +412,12 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) if (!kvm_enabled()) { cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, ¤t_flags); + /* Account this instruction, because we will exit the tb. + This is the first instruction in the block. Therefore + there is no need in restoring CPU state. */ + if (use_icount) { + --cs->icount_decr.u16.low; + } } pause_all_vcpus();