[{"id":3679253,"web_url":"http://patchwork.ozlabs.org/comment/3679253/","msgid":"<33852de5-a2a7-469c-9c08-177b2f3f144c@linaro.org>","list_archive_url":null,"date":"2026-04-20T07:13:52","subject":"Re: [PATCH] hw/arm: Remove hw_error() for the unimplemented\n CM_LMBUSCNT register","submitter":{"id":85046,"url":"http://patchwork.ozlabs.org/api/people/85046/","name":"Philippe Mathieu-Daudé","email":"philmd@linaro.org"},"content":"On 20/4/26 08:49, Thomas Huth wrote:\n> From: Thomas Huth \n> \n> When writing to this register, QEMU currently aborts:\n> \n> $ echo \"readl 0x10000018\" | ./qemu-system-arm -audiodev none,id=snd0 \\\n> -M integratorcp,accel=qtest,audiodev=snd0 -display none -qtest stdio\n> [I 0.000000] OPENED\n> [R +0.001907] readl 0x10000018\n> qemu: hardware error: integratorcm_read: CM_LMBUSCNT\n> [...]\n> Aborted (core dumped)\n> \n> This is bad, a guest should ideally never be able to kill QEMU like this.\n> \n> Now, according to the \"Intergrator/CP User Guide\" from:\n> \n> https://developer.arm.com/documentation/dui0159/b/porting-integrator-ap-and-im-pd1/registers\n> \n> \"The Integrator/AP CM_LMBUSCNT has been removed.\"\n> \n> That means this register does not seem to be implemented on real CP boards\n> at all, only for older AP boards. Thus it should be fine if we simply\n> ignore this register in QEMU and handle it like all other unimplemented\n> registers in the \"default\" handler of the case statement.\n> \n> Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3407\n> Signed-off-by: Thomas Huth \n> ---\n> hw/arm/integratorcp.c | 3 ---\n> 1 file changed, 3 deletions(-)\n\nReviewed-by: Philippe Mathieu-Daudé ","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256\n header.s=google header.b=LNay7zbu;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fzcF51QNBz1yGs\n\tfor ; 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