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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33C9BC43334 for ; Thu, 21 Jul 2022 11:11:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC5958E0003; Thu, 21 Jul 2022 07:11:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A76658E0002; Thu, 21 Jul 2022 07:11:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 93DCF8E0003; Thu, 21 Jul 2022 07:11:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 861DA8E0002 for ; Thu, 21 Jul 2022 07:11:45 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 538D912084F for ; Thu, 21 Jul 2022 07:35:27 +0000 (UTC) X-FDA: 79710296694.11.F4773A2 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by imf11.hostedemail.com (Postfix) with ESMTP id 6BBCC400AD for ; Thu, 21 Jul 2022 07:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658388926; x=1689924926; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=HDZ5ADD7H00ujzYo8f6UW7EI5DQuY8pQPtvATJDvm4I=; b=aT+o2lQ3XDKdTfXwBaMVD1gwuubJqKNkArnVpT4IhlZl5dqmpZCrBoUu sj2tT4dY8SPFVqSUuMkB1Pv/wS/gcm4l/Xmx+wppgTl/+6GmiseDzNGlE Ci82Q0INmiQkPfFGsAxN6QC9/U2icX/Wn6J+p6vP0oD5alS0w/hRKEuql eMYpCioOu54vAw7HN7bUUgm/axuvUW7cFl+08tEQqcOCXjpcXXRaFbJGw HS4LnWRZIK/hrK/vd4/Z2vIdd3Fa65SoBHdEF5pop45FPTvNf+Bp1qmI/ 0/tVkoMvVLlVfSXc27O7wN5SoJd5mABSp7+YauIIPuWXywLH8SDfmZdqz A==; X-IronPort-AV: E=McAfee;i="6400,9594,10414"; a="373276621" X-IronPort-AV: E=Sophos;i="5.92,288,1650956400"; d="scan'208";a="373276621" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jul 2022 00:35:16 -0700 X-IronPort-AV: E=Sophos;i="5.92,288,1650956400"; d="scan'208";a="626004190" Received: from wangwei-desk.sh.intel.com (HELO [10.239.159.152]) ([10.239.159.152]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jul 2022 00:35:06 -0700 Message-ID: <45ae9f57-d595-f202-abb5-26a03a2ca131@linux.intel.com> Date: Thu, 21 Jul 2022 15:34:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v7 11/14] KVM: Register/unregister the guest private memory regions Content-Language: en-US To: Sean Christopherson , "Gupta, Pankaj" Cc: Chao Peng , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org, linux-kselftest@vger.kernel.org, Paolo Bonzini , Jonathan Corbet , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, Quentin Perret , Michael Roth , mhocko@suse.com, Muchun Song References: <20220706082016.2603916-1-chao.p.peng@linux.intel.com> <20220706082016.2603916-12-chao.p.peng@linux.intel.com> <20220719140843.GA84779@chaop.bj.intel.com> <36e671d2-6b95-8e4f-c2ac-fee4b2670c6e@amd.com> <20220720150706.GB124133@chaop.bj.intel.com> From: Wei Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658388926; a=rsa-sha256; cv=none; b=1YEvngvKnzea6cpxby70BkqfqyxUpYBGLUNOBwYiL7J3FjqfJx79F6yvtHUNyOVV8fqenk KJL4xbie1VnQ05ixVC0hlxrFa6NKVRdRHNyV2P33t/oO71SJI3ahiIKAGMyOIEf9/tGgZN HDEUZDixdzKPdOMm+A0GhTILwPbBYhg= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=aT+o2lQ3; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf11.hostedemail.com: domain of wei.w.wang@linux.intel.com has no SPF policy when checking 192.55.52.43) smtp.mailfrom=wei.w.wang@linux.intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658388926; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6cUf5L83c0scFhCyn6w3BgwQpNk61rUOaN9njs/H1xI=; b=0nrxdw4HpP+UT6MpEI9aN7QuOaHVbifwpnMZ9TqLjf6/ACLXkhnNwCH/p1kDlGyQp+uYRP 75O6KDepvYRTDRKFlmp5Gt8U0l4UtFrmIG1imvJynnm5Fp8IgawLnK/36rBH+RS2CGwX82 9jnVT3FrQiZ6Oh8yOmSKnUwLYUlpK4Q= X-Rspam-User: Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=aT+o2lQ3; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf11.hostedemail.com: domain of wei.w.wang@linux.intel.com has no SPF policy when checking 192.55.52.43) smtp.mailfrom=wei.w.wang@linux.intel.com X-Stat-Signature: 455ra1pgu4pesp6kje3wfe3o37dabe9p X-Rspamd-Queue-Id: 6BBCC400AD X-Rspamd-Server: rspam02 X-HE-Tag: 1658388926-358215 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 7/21/22 00:21, Sean Christopherson wrote: > On Wed, Jul 20, 2022, Gupta, Pankaj wrote: >>>>>>> +bool __weak kvm_arch_private_mem_supported(struct kvm *kvm) > Use kvm_arch_has_private_mem(), both because "has" makes it obvious this is checking > a flag of sorts, and to align with other helpers of this nature (and with > CONFIG_HAVE_KVM_PRIVATE_MEM). > > $ git grep kvm_arch | grep supported | wc -l > 0 > $ git grep kvm_arch | grep has | wc -l > 26 > >>>>>>> +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM >>>>>>> + case KVM_MEMORY_ENCRYPT_REG_REGION: >>>>>>> + case KVM_MEMORY_ENCRYPT_UNREG_REGION: { >>>>>>> + struct kvm_enc_region region; >>>>>>> + >>>>>>> + if (!kvm_arch_private_mem_supported(kvm)) >>>>>>> + goto arch_vm_ioctl; >>>>>>> + >>>>>>> + r = -EFAULT; >>>>>>> + if (copy_from_user(®ion, argp, sizeof(region))) >>>>>>> + goto out; >>>>>>> + >>>>>>> + r = kvm_vm_ioctl_set_encrypted_region(kvm, ioctl, ®ion); >>>>>> this is to store private region metadata not only the encrypted region? >>>>> Correct. >>>> Sorry for not being clear, was suggesting name change of this function from: >>>> "kvm_vm_ioctl_set_encrypted_region" to "kvm_vm_ioctl_set_private_region" >>> Though I don't have strong reason to change it, I'm fine with this and >> Yes, no strong reason, just thought "kvm_vm_ioctl_set_private_region" would >> depict the actual functionality :) >> >>> this name matches the above kvm_arch_private_mem_supported perfectly. >> BTW could not understand this, how "kvm_vm_ioctl_set_encrypted_region" >> matches "kvm_arch_private_mem_supported"? > Chao is saying that kvm_vm_ioctl_set_private_region() pairs nicely with > kvm_arch_private_mem_supported(), not that the "encrypted" variant pairs nicely. > > I also like using "private" instead of "encrypted", though we should probably > find a different verb than "set", because calling "set_private" when making the > region shared is confusing. I'm struggling to come up with a good alternative > though. > > kvm_vm_ioctl_set_memory_region() is already taken by KVM_SET_USER_MEMORY_REGION, > and that also means that anything with "memory_region" in the name is bound to be > confusing. > > Hmm, and if we move away from "encrypted", it probably makes sense to pass in > addr+size instead of a kvm_enc_region. > > Maybe this? > > static int kvm_vm_ioctl_set_or_clear_mem_private(struct kvm *kvm, gpa_t gpa, > gpa_t size, bool set_private) > > and then: > > #ifdef CONFIG_HAVE_KVM_PRIVATE_MEM > case KVM_MEMORY_ENCRYPT_REG_REGION: > case KVM_MEMORY_ENCRYPT_UNREG_REGION: { > bool set = ioctl == KVM_MEMORY_ENCRYPT_REG_REGION; > struct kvm_enc_region region; > > if (!kvm_arch_private_mem_supported(kvm)) > goto arch_vm_ioctl; > > r = -EFAULT; > if (copy_from_user(®ion, argp, sizeof(region))) > goto out; > > r = kvm_vm_ioctl_set_or_clear_mem_private(kvm, region.addr, > region.size, set); > break; > } > #endif > > I don't love it, so if someone has a better idea... > Maybe you could tag it with cgs for all the confidential guest support related stuff: e.g. kvm_vm_ioctl_set_cgs_mem() bool is_private = ioctl == KVM_MEMORY_ENCRYPT_REG_REGION; ... kvm_vm_ioctl_set_cgs_mem(, is_private)