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=-4.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 B3479C3B1BD for ; Fri, 14 Feb 2020 18:36:33 +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 838A020848 for ; Fri, 14 Feb 2020 18:36:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KgNBmLdH"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="IlBTVTsH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 838A020848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=OwEJCz2oB3+Rk886YXEHWG6hxn5VarY7Be+vUCdN+3o=; b=KgNBmLdHLV6frA fsRxdc81BjiG/CTa7jZ+res/9OVrFWbVuRV8JcAQDrKCnlR4hkNyOk4YTKKhE6F5h3Z1aWyJJ0n8Z 2xtxSjJDyZZr1ICHyjlBKHWl8rDo+GcCTMLs5H9DXem1kqHavBx38wG/0QzdV8vhhn1SE7q56KT1Z jfPZKSWbnnCDVhTv4X69/oHPBjAR7pHny5xqwp9LefCKSMDhymYyZPokYwRhHZA7ii6xh8MJKAbCd PlgrlepkuB3pg7AyyACSpyCssQucarlSgFqX259Pr9bHfwKFpyAL1rVC6pupzhohbuLGp3Gy+EMua 7mf1wvRIju6uyMZ7029A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j2fpJ-0005Wt-5D; Fri, 14 Feb 2020 18:36:33 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j2fpG-0005Vi-Jz for linux-arm-kernel@lists.infradead.org; Fri, 14 Feb 2020 18:36:31 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BEBCD20848; Fri, 14 Feb 2020 18:36:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581705389; bh=T+ilQI9wpmnmJVmL5LiaSl2V8wIK4X9cI78O+ANnNOE=; h=From:To:Cc:Subject:Date:From; b=IlBTVTsHr/G7gWRjLL220TV6NPEbmZBkt9QuKo/4Rpgju5AedYJhyRse2UusxxeJZ zzQOay2oAzn6jKo984xRFeUNONIWdX8k3ofL0/Ht5Z6qAuuwpqXhUf2Vr9Bvb8Mum0 iOe4t7QGTnK4VAYcCWHOKefn2AH6GdhFEEE6YaWo= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j2fpE-005J5c-2m; Fri, 14 Feb 2020 18:36:28 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 0/2] KVM: arm64: Filtering PMU events Date: Fri, 14 Feb 2020 18:36:13 +0000 Message-Id: <20200214183615.25498-1-maz@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200214_103630_677575_EBBE0CCF X-CRM114-Status: GOOD ( 11.83 ) 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: James Morse , Julien Thierry , Suzuki K Poulose 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 It is at times necessary to prevent a guest from being able to sample certain events if multiple CPUs share resources such as a cache level. In this case, it would be interesting if the VMM could simply prevent certain events from being counted instead of simply not exposing a PMU. Given that most events are not architected, there is no easy way to designate which events shouldn't be counted other than specifying the raw event number. Since I have no idea whether it is better to use an event whitelist or blacklist, the proposed API takes a cue from the x86 version and allows either allowing or denying counting of ranges of events. The event space being pretty large (16bits on ARMv8.1), the default policy is set by the first filter that gets installed (default deny if we first allow, default allow if we first deny). The filter state is global to the guest, despite the PMU being per CPU. I'm not sure whether it would be worth it making it CPU-private. Anyway, I'd be interesting in comments on how people would use this. I'll try to push a patch against kvmtool that implement this shortly (what I have currently is a harcoded set of hacks). Marc Zyngier (2): KVM: arm64: Add PMU event filtering infrastructure KVM: arm64: Document PMU filtering API Documentation/virt/kvm/devices/vcpu.txt | 28 +++++++++ arch/arm64/include/asm/kvm_host.h | 6 ++ arch/arm64/include/uapi/asm/kvm.h | 16 ++++++ virt/kvm/arm/arm.c | 2 + virt/kvm/arm/pmu.c | 76 +++++++++++++++++++++---- 5 files changed, 116 insertions(+), 12 deletions(-) -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel