From patchwork Tue Jan 26 15:15:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 12047095 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=-12.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 EF90FC433E9 for ; Tue, 26 Jan 2021 15:17:39 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 937482311B for ; Tue, 26 Jan 2021 15:17:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 937482311B 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+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=merlin.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=B8IJPYWuWy8KZvSdHCEskmgtbN58+sC7Wp/h25flaHw=; b=urAkM7Ll9YJRTvIoRSJXFz5Nzh G9pd2HmbBpR0XuGuWmV+hzbiA4V0BihaaMQA8EklpixVUHsPXTwm2fsu4Evb2zUSZ64njE3qNr5oP lQ07ucRFnhfX/+VsMmmtnxt7Ctj/9BkWZjmtF4CMopkJsCl/fYRZH4MtG7n1Ke+aMLpYhypjaRUrT oz2Jreow+JwKVg2L6tCPtosE3EbGhU0JxqKsWqWeM5DIMsoWy0MjMymR4RVgRKcXSt2YpOKnnm04i 0lQvuwQT3k+iorIKtZW+K9/+kveGYkX1kJ2YxSEjuvIyT0rMcZ/rGjDG3w/jel1bMd65PChfoChAL 8eRGfQtA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4Q4j-00012p-31; Tue, 26 Jan 2021 15:16:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4Q4g-00011a-LG for linux-arm-kernel@lists.infradead.org; Tue, 26 Jan 2021 15:16:11 +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 A610F206B5; Tue, 26 Jan 2021 15:16:09 +0000 (UTC) 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) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1l4Q4d-00A9nZ-Jk; Tue, 26 Jan 2021 15:16:07 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH 0/2] KVM: arm64: Prevent spurious PMU accesses when no Date: Tue, 26 Jan 2021 15:15:19 +0000 Message-Id: <20210126151521.2958688-1-maz@kernel.org> X-Mailer: git-send-email 2.29.2 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, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, andre.przywara@arm.com, kernel-team@android.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-20210126_101610_773016_ECB869E4 X-CRM114-Status: GOOD ( 11.99 ) 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: Andre Przywara , kernel-team@android.com, James Morse , Julien Thierry , Suzuki K Poulose Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Yet another PMU bug that is only likely to hit under Nested Virt: we unconditionally access PMU registers without checking whether it actually is present. Given that we already have a predicate for this, promote it to a static key, and use that in the world switch. Thanks to Andre for the heads up! Marc Zyngier (2): KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available arch/arm64/kernel/image-vars.h | 3 +++ arch/arm64/kvm/hyp/include/hyp/switch.h | 9 ++++++--- arch/arm64/kvm/perf.c | 10 ++++++++++ arch/arm64/kvm/pmu-emul.c | 10 ---------- include/kvm/arm_pmu.h | 9 +++++++-- 5 files changed, 26 insertions(+), 15 deletions(-)