From nobody Mon Feb 9 05:20:14 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 16351900471871001.9983962673714; Mon, 25 Oct 2021 12:27:27 -0700 (PDT) Received: from localhost ([::1]:59630 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mf5d0-0006gT-3U for importer@patchew.org; Mon, 25 Oct 2021 15:27:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41992) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mf5Pu-0000fq-DT for qemu-devel@nongnu.org; Mon, 25 Oct 2021 15:13:54 -0400 Received: from mail.csgraf.de ([85.25.223.15]:48314 helo=zulu616.server4you.de) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mf5Ps-0000Qf-Nw for qemu-devel@nongnu.org; Mon, 25 Oct 2021 15:13:54 -0400 Received: from localhost.localdomain (dynamic-095-114-012-148.95.114.pool.telefonica.de [95.114.12.148]) by csgraf.de (Postfix) with ESMTPSA id AB55260803C7; Mon, 25 Oct 2021 21:13:50 +0200 (CEST) From: Alexander Graf To: Cameron Esfahani Subject: [PATCH] hvf: arm: Ignore cache operations on MMIO Date: Mon, 25 Oct 2021 21:13:49 +0200 Message-Id: <20211025191349.52992-1-agraf@csgraf.de> X-Mailer: git-send-email 2.30.1 (Apple Git-130) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=85.25.223.15; envelope-from=agraf@csgraf.de; helo=zulu616.server4you.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kettenis@openbsd.org, qemu-devel@nongnu.org, AJ Barris , Roman Bolshakov , Paolo Bonzini , osy@github.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1635190048998100003 Content-Type: text/plain; charset="utf-8" Apple's Hypervisor.Framework forwards cache operations as MMIO traps into user space. For MMIO however, these have no meaning: There is no cache attached to them. So let's filter SYS instructions for DATA exits out and treat them as nops. This fixes OpenBSD booting as guest. Signed-off-by: Alexander Graf Reported-by: AJ Barris Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- target/arm/hvf/hvf.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c index bff3e0cde7..46ff4892a7 100644 --- a/target/arm/hvf/hvf.c +++ b/target/arm/hvf/hvf.c @@ -1098,6 +1098,33 @@ static void hvf_sync_vtimer(CPUState *cpu) } } =20 +static bool hvf_emulate_insn(CPUState *cpu) +{ + ARMCPU *arm_cpu =3D ARM_CPU(cpu); + CPUARMState *env =3D &arm_cpu->env; + uint32_t insn; + + /* + * We ran into an instruction that traps for data, but is not + * hardware predecoded. This should not ever happen for well + * behaved guests. Let's try to see if we can somehow rescue + * the situation. + */ + + cpu_synchronize_state(cpu); + if (cpu_memory_rw_debug(cpu, env->pc, &insn, 4, 0)) { + /* Could not read the instruction */ + return false; + } + + if ((insn & 0xffc00000) =3D=3D 0xd5000000) { + /* MSR/MRS/SYS/SYSL - happens for cache ops which are nops on data= */ + return true; + } + + return false; +} + int hvf_vcpu_exec(CPUState *cpu) { ARMCPU *arm_cpu =3D ARM_CPU(cpu); @@ -1156,6 +1183,11 @@ int hvf_vcpu_exec(CPUState *cpu) hvf_exit->exception.physical_address, isv, iswrite, s1ptw, len, srt); =20 + if (!isv) { + g_assert(hvf_emulate_insn(cpu)); + advance_pc =3D true; + break; + } assert(isv); =20 if (iswrite) { --=20 2.30.1 (Apple Git-130)