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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 04D54C10F27 for ; Mon, 9 Mar 2020 12:48:50 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 7C4B420828 for ; Mon, 9 Mar 2020 12:48:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="DByraDkc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C4B420828 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 005EB4A51E; Mon, 9 Mar 2020 08:48:49 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vAXus1zHkM7c; Mon, 9 Mar 2020 08:48:47 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id DFC5E4A51F; Mon, 9 Mar 2020 08:48:47 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 699084A523 for ; Mon, 9 Mar 2020 08:48:46 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZFEJHLen-FlP for ; Mon, 9 Mar 2020 08:48:45 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 557354005D for ; Mon, 9 Mar 2020 08:48:45 -0400 (EDT) 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 285F620727; Mon, 9 Mar 2020 12:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583758124; bh=CSS+5INePZvmhimi/unCx0TEoioRr+d/iqq75Std27I=; h=From:To:Cc:Subject:Date:From; b=DByraDkcHaWW6E85jLzUQ23KZZw8zgL/sHKV0sqqrojbjcSmdvjv4QpPh1LVwr1w9 BPEixptW++IaqFflCSjCZ5E03AGMNGh4mgsm58VieYChgPjUQaR/JwiZuTXPIjHuJW scaLyKQSpvuvNdN/wB1L2tH32qEregObfh7UZf+M= 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 1jBHpq-00BHiN-C7; Mon, 09 Mar 2020 12:48:42 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH v2 0/2] KVM: arm64: Filtering PMU events Date: Mon, 9 Mar 2020 12:48:35 +0000 Message-Id: <20200309124837.19908-1-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, robin.murphy@arm.com, mark.rutland@arm.com, eric.auger@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Robin Murphy X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu 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 hiding the 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. As an example of what can be done in userspace, I have the corresponding kvmtool hack here[1]. * From v1: - Cleaned up handling of the cycle counter - Documented restrictions on SW_INC, CHAIN and CPU_CYCLES events [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/kvmtool.git/commit/?h=pmu-filter Marc Zyngier (2): KVM: arm64: Add PMU event filtering infrastructure KVM: arm64: Document PMU filtering API Documentation/virt/kvm/devices/vcpu.rst | 40 ++++++++++++ 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 | 84 ++++++++++++++++++++----- 5 files changed, 132 insertions(+), 16 deletions(-) -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 29D6DC10F27 for ; 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Mon, 09 Mar 2020 12:48:46 +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 285F620727; Mon, 9 Mar 2020 12:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583758124; bh=CSS+5INePZvmhimi/unCx0TEoioRr+d/iqq75Std27I=; h=From:To:Cc:Subject:Date:From; b=DByraDkcHaWW6E85jLzUQ23KZZw8zgL/sHKV0sqqrojbjcSmdvjv4QpPh1LVwr1w9 BPEixptW++IaqFflCSjCZ5E03AGMNGh4mgsm58VieYChgPjUQaR/JwiZuTXPIjHuJW scaLyKQSpvuvNdN/wB1L2tH32qEregObfh7UZf+M= 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 1jBHpq-00BHiN-C7; Mon, 09 Mar 2020 12:48:42 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH v2 0/2] KVM: arm64: Filtering PMU events Date: Mon, 9 Mar 2020 12:48:35 +0000 Message-Id: <20200309124837.19908-1-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, robin.murphy@arm.com, mark.rutland@arm.com, eric.auger@redhat.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-20200309_054845_356881_893F723E X-CRM114-Status: GOOD ( 12.07 ) 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: Mark Rutland , Suzuki K Poulose , Eric Auger , James Morse , Robin Murphy , Julien Thierry 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 hiding the 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. As an example of what can be done in userspace, I have the corresponding kvmtool hack here[1]. * From v1: - Cleaned up handling of the cycle counter - Documented restrictions on SW_INC, CHAIN and CPU_CYCLES events [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/kvmtool.git/commit/?h=pmu-filter Marc Zyngier (2): KVM: arm64: Add PMU event filtering infrastructure KVM: arm64: Document PMU filtering API Documentation/virt/kvm/devices/vcpu.rst | 40 ++++++++++++ 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 | 84 ++++++++++++++++++++----- 5 files changed, 132 insertions(+), 16 deletions(-) -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 B5268C10F27 for ; Mon, 9 Mar 2020 12:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8ED6020848 for ; Mon, 9 Mar 2020 12:48:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583758126; bh=CSS+5INePZvmhimi/unCx0TEoioRr+d/iqq75Std27I=; h=From:To:Cc:Subject:Date:List-ID:From; b=VJFAabpgI8R8SKQh+5aX59OyCIa2NhbwJI6FYRfiLVuMtsozVkcDzCAWK1Xlp36kW BgSwkpSDDpWJVeC8H1E18xmWEdB2FTRRsscnZP2CW7datiFj1UoiWZUYs2AqmhwTGE qojuPJyidkeZYETm2Taj6cwG1qE8ssrIcYBAid0o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbgCIMso (ORCPT ); Mon, 9 Mar 2020 08:48:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:55212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725956AbgCIMso (ORCPT ); Mon, 9 Mar 2020 08:48:44 -0400 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 285F620727; Mon, 9 Mar 2020 12:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583758124; bh=CSS+5INePZvmhimi/unCx0TEoioRr+d/iqq75Std27I=; h=From:To:Cc:Subject:Date:From; b=DByraDkcHaWW6E85jLzUQ23KZZw8zgL/sHKV0sqqrojbjcSmdvjv4QpPh1LVwr1w9 BPEixptW++IaqFflCSjCZ5E03AGMNGh4mgsm58VieYChgPjUQaR/JwiZuTXPIjHuJW scaLyKQSpvuvNdN/wB1L2tH32qEregObfh7UZf+M= 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 1jBHpq-00BHiN-C7; Mon, 09 Mar 2020 12:48:42 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: James Morse , Julien Thierry , Suzuki K Poulose , Robin Murphy , Mark Rutland , Eric Auger Subject: [PATCH v2 0/2] KVM: arm64: Filtering PMU events Date: Mon, 9 Mar 2020 12:48:35 +0000 Message-Id: <20200309124837.19908-1-maz@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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, robin.murphy@arm.com, mark.rutland@arm.com, eric.auger@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.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 hiding the 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. As an example of what can be done in userspace, I have the corresponding kvmtool hack here[1]. * From v1: - Cleaned up handling of the cycle counter - Documented restrictions on SW_INC, CHAIN and CPU_CYCLES events [1] https://git.kernel.org/pub/scm/linux/kernel/git/maz/kvmtool.git/commit/?h=pmu-filter Marc Zyngier (2): KVM: arm64: Add PMU event filtering infrastructure KVM: arm64: Document PMU filtering API Documentation/virt/kvm/devices/vcpu.rst | 40 ++++++++++++ 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 | 84 ++++++++++++++++++++----- 5 files changed, 132 insertions(+), 16 deletions(-) -- 2.20.1