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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 560D5C4363D for ; Tue, 22 Sep 2020 01:48:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26EAC239D4 for ; Tue, 22 Sep 2020 01:48:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729113AbgIVBsk (ORCPT ); Mon, 21 Sep 2020 21:48:40 -0400 Received: from mga11.intel.com ([192.55.52.93]:23180 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728726AbgIVBsk (ORCPT ); Mon, 21 Sep 2020 21:48:40 -0400 IronPort-SDR: w0VtyY6O5VdxRNet/a3IMR7hOm+Vkw5IyHXYU/NCOSyE8EAK0zuJ1StJvx5Ce2KUbVpikVpiFo MjMQRkPmv8lA== X-IronPort-AV: E=McAfee;i="6000,8403,9751"; a="157889550" X-IronPort-AV: E=Sophos;i="5.77,288,1596524400"; d="scan'208";a="157889550" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2020 18:48:40 -0700 IronPort-SDR: EKmRzOaBuIIW9inV+MyT74mc9qgnnr0UMVwHIISz1HktLahGd3wNsAXDVEIGZvfEifGjgr4AFM SqGdYcQR+2JQ== X-IronPort-AV: E=Sophos;i="5.77,288,1596524400"; d="scan'208";a="510967132" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.160]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Sep 2020 18:48:39 -0700 Date: Mon, 21 Sep 2020 18:48:38 -0700 From: Sean Christopherson To: Vipin Sharma Cc: thomas.lendacky@amd.com, pbonzini@redhat.com, tj@kernel.org, lizefan@huawei.com, joro@8bytes.org, corbet@lwn.net, brijesh.singh@amd.com, jon.grimm@amd.com, eric.vantassell@amd.com, gingell@google.com, rientjes@google.com, kvm@vger.kernel.org, x86@kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC Patch 0/2] KVM: SVM: Cgroup support for SVM SEV ASIDs Message-ID: <20200922014836.GA26507@linux.intel.com> References: <20200922004024.3699923-1-vipinsh@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200922004024.3699923-1-vipinsh@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Sep 21, 2020 at 05:40:22PM -0700, Vipin Sharma wrote: > Hello, > > This patch series adds a new SEV controller for tracking and limiting > the usage of SEV ASIDs on the AMD SVM platform. > > SEV ASIDs are used in creating encrypted VM and lightweight sandboxes > but this resource is in very limited quantity on a host. > > This limited quantity creates issues like SEV ASID starvation and > unoptimized scheduling in the cloud infrastructure. > > SEV controller provides SEV ASID tracking and resource control > mechanisms. This should be genericized to not be SEV specific. TDX has a similar scarcity issue in the form of key IDs, which IIUC are analogous to SEV ASIDs (gave myself a quick crash course on SEV ASIDs). Functionally, I doubt it would change anything, I think it'd just be a bunch of renaming. The hardest part would probably be figuring out a name :-). Another idea would be to go even more generic and implement a KVM cgroup that accounts the number of VMs of a particular type, e.g. legacy, SEV, SEV-ES?, and TDX. That has potential future problems though as it falls apart if hardware every supports 1:MANY VMs:KEYS, or if there is a need to account keys outside of KVM, e.g. if MKTME for non-KVM cases ever sees the light of day.