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=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 AFCCDC433DF for ; Mon, 17 Aug 2020 07:39:20 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 1F07E207DF for ; Mon, 17 Aug 2020 07:39:19 +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="MZk/ZzO0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F07E207DF 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 7E8A44BA11; Mon, 17 Aug 2020 03:39:19 -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 kS4UIkk0cM4c; Mon, 17 Aug 2020 03:39:18 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5E56A4BF16; Mon, 17 Aug 2020 03:39:18 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C7B424BF12 for ; Mon, 17 Aug 2020 03:39:16 -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 qepmjXX7eAXH for ; Mon, 17 Aug 2020 03:39:15 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 584D34BA11 for ; Mon, 17 Aug 2020 03:39:15 -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 14CC420758; Mon, 17 Aug 2020 07:39:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597649954; bh=5f7u17TvsjTrzreApIZ4x0jr/04LEQs1hIO1IBZJBVg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MZk/ZzO0Xwj51vzBkOh6djd6cauo+roP/pRXxR0PLsTP9CxwmDwEQWJzTOZ+efS5N QUUrA+K/1xW95pGQ2wvCVRVUyJzPQ17UZXIXt1cfl5+9y6EMMgKTNeEDjcoRzAfaIj XlILTLZZUpgl+E35JmvL+d76aYnLmH9VvHC3F0nA= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1k7Zjc-003T4X-BL; Mon, 17 Aug 2020 08:39:12 +0100 MIME-Version: 1.0 Date: Mon, 17 Aug 2020 08:39:12 +0100 From: Marc Zyngier To: Keqian Zhu Subject: Re: [PATCH 2/3] KVM: uapi: Remove KVM_DEV_TYPE_ARM_PV_TIME in kvm_device_type In-Reply-To: <20200817033729.10848-3-zhukeqian1@huawei.com> References: <20200817033729.10848-1-zhukeqian1@huawei.com> <20200817033729.10848-3-zhukeqian1@huawei.com> User-Agent: Roundcube Webmail/1.4.7 Message-ID: X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: zhukeqian1@huawei.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, steven.price@arm.com, wanghaibin.wang@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvm@vger.kernel.org, Catalin Marinas , linux-kernel@vger.kernel.org, Steven Price , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.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 2020-08-17 04:37, Keqian Zhu wrote: > ARM64 PV-time ST is configured by userspace through vCPU attribute, > and KVM_DEV_TYPE_ARM_PV_TIME is unused. > > Signed-off-by: Keqian Zhu > --- > include/uapi/linux/kvm.h | 2 -- > tools/include/uapi/linux/kvm.h | 2 -- > 2 files changed, 4 deletions(-) > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 4fdf303..9a6b97e 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1258,8 +1258,6 @@ enum kvm_device_type { > #define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS > KVM_DEV_TYPE_XIVE, > #define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE > - KVM_DEV_TYPE_ARM_PV_TIME, > -#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME > KVM_DEV_TYPE_MAX, > }; > > diff --git a/tools/include/uapi/linux/kvm.h > b/tools/include/uapi/linux/kvm.h > index 4fdf303..9a6b97e 100644 > --- a/tools/include/uapi/linux/kvm.h > +++ b/tools/include/uapi/linux/kvm.h > @@ -1258,8 +1258,6 @@ enum kvm_device_type { > #define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS > KVM_DEV_TYPE_XIVE, > #define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE > - KVM_DEV_TYPE_ARM_PV_TIME, > -#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME > KVM_DEV_TYPE_MAX, > }; No. You can't drop anything from UAPI, used or not. Doing so will break the compilation of any userspace that, for any reason, references this value. We cannot reuse this value in the future either, as it would create a we wouldn't know which device to create. It is pretty unfortunate that PV time has turned into such a train wreck, but that's what we have now, and it has to stay. M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm