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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AFC01CD11BF for ; Tue, 19 Mar 2024 15:34:38 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmbTi-0001pW-JE; Tue, 19 Mar 2024 11:34:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmbTg-0001p8-Ml for qemu-devel@nongnu.org; Tue, 19 Mar 2024 11:34:12 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmbTS-0003GG-QL for qemu-devel@nongnu.org; Tue, 19 Mar 2024 11:34:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710862437; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=LTv0c9gBsGx2cGoLzFXhFtEOz/PUb4iNz/cutnWVCfY=; b=ODXGlZ1dFAVoFPGR3wPuSLvwZM4Dr8jb6QGpNvG2C7tewEEvkdWOc+aMgp7B2iTot5lo74 Xox0bCL7WRR4pz202kg8QC0zdZbHruAIE3hUH+OusV/kWfqi3csIqwqoZCv2VKpebFswyo tQxkNca0oMDoVcdIrIWz0+UiPCGubmk= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-571-cHXfH-IXM4GpTBHYlzoxHg-1; Tue, 19 Mar 2024 11:33:51 -0400 X-MC-Unique: cHXfH-IXM4GpTBHYlzoxHg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 84F6D1C2CDE6; Tue, 19 Mar 2024 15:33:51 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3698F492BD1; Tue, 19 Mar 2024 15:33:50 +0000 (UTC) Date: Tue, 19 Mar 2024 15:33:44 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Shaoqin Huang Cc: qemu-arm@nongnu.org, Eric Auger , Sebastian Ott , Peter Maydell , Paolo Bonzini , qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: Re: [PATCH v7] arm/kvm: Enable support for KVM_ARM_VCPU_PMU_V3_FILTER Message-ID: References: <20240221063431.76992-1-shahuang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240221063431.76992-1-shahuang@redhat.com> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.422, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Feb 21, 2024 at 01:34:31AM -0500, Shaoqin Huang wrote: > diff --git a/docs/system/arm/cpu-features.rst b/docs/system/arm/cpu-features.rst > index a5fb929243..7c8f6a60ef 100644 > --- a/docs/system/arm/cpu-features.rst > +++ b/docs/system/arm/cpu-features.rst > @@ -204,6 +204,29 @@ the list of KVM VCPU features and their descriptions. > the guest scheduler behavior and/or be exposed to the guest > userspace. > > +``kvm-pmu-filter`` > + By default kvm-pmu-filter is disabled. This means that by default all pmu > + events will be exposed to guest. > + > + KVM implements PMU Event Filtering to prevent a guest from being able to > + sample certain events. It depends on the KVM_ARM_VCPU_PMU_V3_FILTER > + attribute supported in KVM. It has the following format: > + > + kvm-pmu-filter="{A,D}:start-end[;{A,D}:start-end...]" > + > + The A means "allow" and D means "deny", start is the first event of the > + range and the end is the last one. The first registered range defines > + the global policy(global ALLOW if the first @action is DENY, global DENY > + if the first @action is ALLOW). The start and end only support hexadecimal > + format. For example: > + > + kvm-pmu-filter="A:0x11-0x11;A:0x23-0x3a;D:0x30-0x30" > + > + Since the first action is allow, we have a global deny policy. It > + will allow event 0x11 (The cycle counter), events 0x23 to 0x3a are > + also allowed except the event 0x30 which is denied, and all the other > + events are denied. Can you document whether the policy evaluation stops at the first matching range, or checks all ranges ie, if you have kvm-pmu-filter="A:0x1-0x9;D=0x7-0x7" will an input of '0x7' be allowed (because it matches the first range and stops), or denied (because the second range overrides the result of the first) With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|