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=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 514F3C2D0E4 for ; Fri, 27 Nov 2020 08:50:12 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 85B1622249 for ; Fri, 27 Nov 2020 08:50:11 +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="efktCWKG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85B1622249 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 B80684B893; Fri, 27 Nov 2020 03:50:10 -0500 (EST) 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 1VrCU0EtUrSb; Fri, 27 Nov 2020 03:50:09 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0BEE64C256; Fri, 27 Nov 2020 03:50:09 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id E88B94B8FC for ; Fri, 27 Nov 2020 03:50:07 -0500 (EST) 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 HNHUyTEZ97bF for ; Fri, 27 Nov 2020 03:50:06 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 0A3D34B850 for ; Fri, 27 Nov 2020 03:50:05 -0500 (EST) 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 9496722249; Fri, 27 Nov 2020 08:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606467004; bh=MX9vJKbH3cxWgpHtoGd0wZlzLIS8UOK+zuJffSAUtew=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=efktCWKGLzw7Um1ysYIPbSerZihvqFnqpGW/vr/Hcc/V/ddM4k8d485Tton7Q0I6i kPiXyzJHwrofdgbqqSOcB0hdrD+IvsHqBo1t48D2iXD6jctmEbVLhLbHIi4EVRhrxN 8+OEVPuekmlC2pHLxhVYrhqMa2a7sC0TEisotaL8= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kiZS6-00E0id-EK; Fri, 27 Nov 2020 08:50:02 +0000 MIME-Version: 1.0 Date: Fri, 27 Nov 2020 08:50:02 +0000 From: Marc Zyngier To: Alexandru Elisei Subject: Re: [PATCH 5/8] KVM: arm64: Remove PMU RAZ/WI handling In-Reply-To: References: <20201113182602.471776-1-maz@kernel.org> <20201113182602.471776-6-maz@kernel.org> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <7ae93087a57bd5f6a348f0d4d6a7db2d@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: alexandru.elisei@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, 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 Cc: kernel-team@android.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 2020-11-26 15:06, Alexandru Elisei wrote: > Hi Marc, > > This patch looks correct to me, I checked in the Arm ARM DDI 0487F.b > and indeed > all accesses to the PMU registers are UNDEFINED if the PMU is not > present. > > I checked all the accessors and now all the PMU registers that KVM > emulates will > inject an undefined exception if the VCPU feature isn't set. There's > one register > that we don't emulate, PMMIR_EL1, I suppose that's because it's part of > PMU > ARMv8.4 and KVM advertises ARMv8.1; if the guest tries to access it, it > will get > an undefined exception and KVM will print a warning in > emulate_sys_reg(). Funny that. I wrote a patch for that a long while ago, and obviously never did anything with it [1]... Actually, the whole series was silently dropped. I guess I had other things to think about at the time! Let me pick that up again. > Reviewed-by: Alexandru Elisei Thanks! M. [1] https://lore.kernel.org/kvmarm/20200216185324.32596-6-maz@kernel.org/ -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm