From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 200D9C31E46 for ; Wed, 12 Jun 2019 12:48:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EAA2F20684 for ; Wed, 12 Jun 2019 12:48:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="CtpeYAsS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EAA2F20684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pP90VNatcnq2rINE2LkWITt7JXmPl8Zs4hES4S4WjUQ=; b=CtpeYAsSAp28TT Z/PtS3l1VIGO9GJEJI+ly+fQMGuAFHs7c/dcxeoJST7+P19t/9zD2O3B8Vq8N9hGMRA3K6M78qsir 1erQMAVPMMSmQc5jIPzr9mnAUITJdgMpGufPZG5wTAOSc7RZyqN1Pb1f8du5wwAJS2UogGQc7zb30 eCvdeXuzWwqdj5OsI/oFNRH4y4ZYkSuua1lQGIWIUr5WspkTXZ7/V0f1kNfU/hJra+/t+9MqUtUch QtdHbQ2ULWNfd8MLtawMVQGED3GCDr18paKTAsdU8RJ/SNcxdOZi/dZZFFmEEStnSJ8lyBJ/cjjIR 9pXo6bs3YDrynkLscwNw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hb2ft-0003Pb-DR; Wed, 12 Jun 2019 12:48:21 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hb2fk-0003Gq-9Y for linux-arm-kernel@lists.infradead.org; Wed, 12 Jun 2019 12:48:13 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 80036337; Wed, 12 Jun 2019 05:48:09 -0700 (PDT) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 39D8E3F246; Wed, 12 Jun 2019 05:48:07 -0700 (PDT) Subject: Re: [PATCH v1 1/5] KVM: arm/arm64: Remove kvm_mmio_emulate tracepoint To: Zenghui Yu References: <1560330526-15468-1-git-send-email-yuzenghui@huawei.com> <1560330526-15468-2-git-send-email-yuzenghui@huawei.com> From: James Morse Message-ID: Date: Wed, 12 Jun 2019 13:48:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <1560330526-15468-2-git-send-email-yuzenghui@huawei.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190612_054812_398841_1BD8F808 X-CRM114-Status: GOOD ( 11.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: acme@redhat.com, kvm@vger.kernel.org, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, acme@kernel.org, linuxarm@huawei.com, linux-perf-users@vger.kernel.org, peterz@infradead.org, alexander.shishkin@linux.intel.com, mingo@redhat.com, xiexiangyou@huawei.com, ganapatrao.kulkarni@cavium.com, namhyung@kernel.org, jolsa@redhat.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On 12/06/2019 10:08, Zenghui Yu wrote: > In current KVM/ARM code, no one will invoke trace_kvm_mmio_emulate(). > Remove this TRACE_EVENT definition. Oooer. We can't just go removing these things, they are visible to user-space. I recall an article on this: https://lwn.net/Articles/737530/ "Another attempt to address the tracepoint ABI problem" I agree this is orphaned, it was added by commit 45e96ea6b369 ("KVM: ARM: Handle I/O aborts"), but there never was a caller. The problem with removing it is /sys/kernel/debug/tracing/events/kvm/kvm_mmio_emulate disappears. Any program relying on that being present (but useless) is now broken. Thanks, James > diff --git a/virt/kvm/arm/trace.h b/virt/kvm/arm/trace.h > index 204d210..8b7dff2 100644 > --- a/virt/kvm/arm/trace.h > +++ b/virt/kvm/arm/trace.h > @@ -114,27 +114,6 @@ > __entry->type, __entry->vcpu_idx, __entry->irq_num, __entry->level) > ); > > -TRACE_EVENT(kvm_mmio_emulate, > - TP_PROTO(unsigned long vcpu_pc, unsigned long instr, > - unsigned long cpsr), > - TP_ARGS(vcpu_pc, instr, cpsr), > - > - TP_STRUCT__entry( > - __field( unsigned long, vcpu_pc ) > - __field( unsigned long, instr ) > - __field( unsigned long, cpsr ) > - ), > - > - TP_fast_assign( > - __entry->vcpu_pc = vcpu_pc; > - __entry->instr = instr; > - __entry->cpsr = cpsr; > - ), > - > - TP_printk("Emulate MMIO at: 0x%08lx (instr: %08lx, cpsr: %08lx)", > - __entry->vcpu_pc, __entry->instr, __entry->cpsr) > -); > - > TRACE_EVENT(kvm_unmap_hva_range, > TP_PROTO(unsigned long start, unsigned long end), > TP_ARGS(start, end), > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel