From patchwork Fri Oct 11 12:39:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11185351 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CE96A1709 for ; Fri, 11 Oct 2019 12:40:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5F3A222C4 for ; Fri, 11 Oct 2019 12:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570797620; bh=Zt+pHSPxfhjzB1EMAAlN0b3r/E15xPAOqliI4X1I1t4=; h=From:To:Cc:Subject:Date:List-ID:From; b=UHWbrIJo3GNbNshZVVwL91ynkx6TJHhja8/Ez4jc4ZORNRX6G7XXk3b6N2U2TiVJk uM9+YfahaE8lUQaYCPHVRnQG3c0zxg0qAUPGswxKnJGLaay+QTk/OJq1zyghJ2RqOd TRu3Xu9+XLtoT2QMR1TGO0A7sFOOK8oV7QXzKiG0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728152AbfJKMkS (ORCPT ); Fri, 11 Oct 2019 08:40:18 -0400 Received: from inca-roads.misterjones.org ([213.251.177.50]:36326 "EHLO inca-roads.misterjones.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727589AbfJKMkS (ORCPT ); Fri, 11 Oct 2019 08:40:18 -0400 Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:DHE-RSA-AES128-GCM-SHA256:128) (Exim 4.80) (envelope-from ) id 1iIuDO-00062U-Br; Fri, 11 Oct 2019 14:40:14 +0200 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Will Deacon , Mark Rutland , James Morse , Julien Thierry , Suzuki K Poulose , Andrew Murray Subject: [PATCH v3 0/4] KVM: arm64: Assorted PMU emulation fixes Date: Fri, 11 Oct 2019 13:39:50 +0100 Message-Id: <20191011123954.31378-1-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, will@kernel.org, mark.rutland@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, andrew.murray@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org I recently came across a number of PMU emulation bugs, all which can result in unexpected behaviours in an unsuspecting guest. The first two patches already have been discussed on the list, but I'm including them here as part of a slightly longer series. The third patch is new as of v2, and fixes a bug preventing chained events from ever being used. The last patch fixes an issue that has been here from day one, where we confuse architectural overflow of a counter and perf sampling period, and uses a terrible hack^W^W creative way to interact with the underlying PMU driver so that we can reload the period when handling the overflow. * From v2 [1] - Dropped PMUv3 patch and moved the logic into the KVM code - Properly use UPDATE/RELOAD - Collected Andrew's RB [1] https://lore.kernel.org/kvmarm/20191008160128.8872-1-maz@kernel.org/ Marc Zyngier (4): KVM: arm64: pmu: Fix cycle counter truncation arm64: KVM: Handle PMCR_EL0.LC as RES1 on pure AArch64 systems KVM: arm64: pmu: Set the CHAINED attribute before creating the in-kernel event KVM: arm64: pmu: Reset sample period on overflow handling arch/arm64/kvm/sys_regs.c | 4 ++++ virt/kvm/arm/pmu.c | 48 ++++++++++++++++++++++++++++----------- 2 files changed, 39 insertions(+), 13 deletions(-)