From: David Hildenbrand <david@redhat.com>
To: Chao Peng <chao.p.peng@linux.intel.com>,
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
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Hugh Dickins <hughd@google.com>, Jeff Layton <jlayton@kernel.org>,
"J . Bruce Fields" <bfields@fieldses.org>,
Andrew Morton <akpm@linux-foundation.org>,
Shuah Khan <shuah@kernel.org>, Mike Rapoport <rppt@kernel.org>,
Steven Price <steven.price@arm.com>,
"Maciej S . Szmigiero" <mail@maciej.szmigiero.name>,
Vlastimil Babka <vbabka@suse.cz>,
Vishal Annapurve <vannapurve@google.com>,
Yu Zhang <yu.c.zhang@linux.intel.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com,
ak@linux.intel.com, aarcange@redhat.com, ddutile@redhat.com,
dhildenb@redhat.com, Quentin Perret <qperret@google.com>,
Michael Roth <michael.roth@amd.com>,
mhocko@suse.com, Muchun Song <songmuchun@bytedance.com>
Subject: Re: [PATCH v7 05/14] mm/memfd: Introduce MFD_INACCESSIBLE flag
Date: Fri, 5 Aug 2022 15:28:50 +0200 [thread overview]
Message-ID: <203c752f-9439-b5ae-056c-27b2631dcb81@redhat.com> (raw)
In-Reply-To: <20220706082016.2603916-6-chao.p.peng@linux.intel.com>
On 06.07.22 10:20, Chao Peng wrote:
> Introduce a new memfd_create() flag indicating the content of the
> created memfd is inaccessible from userspace through ordinary MMU
> access (e.g., read/write/mmap). However, the file content can be
> accessed via a different mechanism (e.g. KVM MMU) indirectly.
>
> It provides semantics required for KVM guest private memory support
> that a file descriptor with this flag set is going to be used as the
> source of guest memory in confidential computing environments such
> as Intel TDX/AMD SEV but may not be accessible from host userspace.
>
> The flag can not coexist with MFD_ALLOW_SEALING, future sealing is
> also impossible for a memfd created with this flag.
It's kind of weird to have it that way. Why should the user have to
care? It's the notifier requirement to have that, no?
Why can't we handle that when register a notifier? If anything is
already mapped, fail registering the notifier if the notifier has these
demands. If registering succeeds, block it internally.
Or what am I missing? We might not need the memfile set flag semantics
eventually and would not have to expose such a flag to user space.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2022-08-05 13:29 UTC|newest]
Thread overview: 172+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-06 8:20 [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory Chao Peng
2022-07-06 8:20 ` [PATCH v7 01/14] mm: Add F_SEAL_AUTO_ALLOCATE seal to memfd Chao Peng
2022-07-21 9:44 ` David Hildenbrand
2022-07-21 9:50 ` David Hildenbrand
2022-07-21 15:05 ` Sean Christopherson
2022-07-25 13:46 ` Chao Peng
2022-07-21 10:27 ` Gupta, Pankaj
2022-07-25 13:54 ` Chao Peng
2022-07-25 14:49 ` Gupta, Pankaj
2022-07-25 13:42 ` Chao Peng
2022-08-05 17:55 ` Paolo Bonzini
2022-08-05 18:06 ` David Hildenbrand
2022-08-10 9:40 ` Chao Peng
2022-08-10 9:38 ` Chao Peng
2022-08-17 23:41 ` Kirill A. Shutemov
2022-08-18 9:09 ` Paolo Bonzini
2022-08-23 7:36 ` David Hildenbrand
2022-08-24 10:20 ` Chao Peng
2022-08-26 15:19 ` Fuad Tabba
2022-08-29 15:18 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 02/14] selftests/memfd: Add tests for F_SEAL_AUTO_ALLOCATE Chao Peng
2022-08-05 13:11 ` David Hildenbrand
2022-07-06 8:20 ` [PATCH v7 03/14] mm: Introduce memfile_notifier Chao Peng
2022-08-05 13:22 ` David Hildenbrand
2022-08-10 9:22 ` Chao Peng
2022-08-10 10:05 ` David Hildenbrand
2022-08-10 14:38 ` Sean Christopherson
2022-08-11 12:27 ` Quentin Perret
2022-08-11 13:39 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 04/14] mm/shmem: Support memfile_notifier Chao Peng
2022-07-12 18:02 ` Gupta, Pankaj
2022-07-13 7:44 ` Chao Peng
2022-07-13 10:01 ` Gupta, Pankaj
2022-07-13 23:49 ` Chao Peng
2022-07-14 4:15 ` Gupta, Pankaj
2022-08-05 13:26 ` David Hildenbrand
2022-08-10 9:25 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 05/14] mm/memfd: Introduce MFD_INACCESSIBLE flag Chao Peng
2022-08-05 13:28 ` David Hildenbrand [this message]
2022-08-10 9:37 ` Chao Peng
2022-08-10 9:55 ` David Hildenbrand
2022-08-11 13:17 ` Chao Peng
2022-09-07 16:18 ` Kirill A. Shutemov
2022-07-06 8:20 ` [PATCH v7 06/14] KVM: Rename KVM_PRIVATE_MEM_SLOTS to KVM_INTERNAL_MEM_SLOTS Chao Peng
2022-07-06 8:20 ` [PATCH v7 07/14] KVM: Use gfn instead of hva for mmu_notifier_retry Chao Peng
2022-07-15 11:36 ` Gupta, Pankaj
2022-07-18 13:29 ` Chao Peng
2022-07-18 15:26 ` Sean Christopherson
2022-07-19 14:02 ` Chao Peng
2022-08-04 7:10 ` Isaku Yamahata
2022-08-10 8:19 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 08/14] KVM: Rename mmu_notifier_* Chao Peng
2022-07-29 19:02 ` Sean Christopherson
2022-08-03 10:13 ` Chao Peng
2022-08-05 19:54 ` Paolo Bonzini
2022-08-10 8:09 ` Chao Peng
2023-05-23 7:19 ` Kautuk Consul
2023-05-23 14:19 ` Sean Christopherson
2023-05-24 6:12 ` Kautuk Consul
2023-05-24 20:16 ` Sean Christopherson
2023-05-24 20:33 ` Peter Zijlstra
2023-05-24 21:39 ` Sean Christopherson
2023-05-25 8:54 ` Peter Zijlstra
2023-05-25 3:52 ` Kautuk Consul
2023-05-24 20:28 ` Peter Zijlstra
2022-07-06 8:20 ` [PATCH v7 09/14] KVM: Extend the memslot to support fd-based private memory Chao Peng
2022-07-29 19:51 ` Sean Christopherson
2022-08-03 10:08 ` Chao Peng
2022-08-03 14:42 ` Sean Christopherson
2022-07-06 8:20 ` [PATCH v7 10/14] KVM: Add KVM_EXIT_MEMORY_FAULT exit Chao Peng
2022-07-06 8:20 ` [PATCH v7 11/14] KVM: Register/unregister the guest private memory regions Chao Peng
2022-07-19 8:00 ` Gupta, Pankaj
2022-07-19 14:08 ` Chao Peng
2022-07-19 14:23 ` Gupta, Pankaj
2022-07-20 15:07 ` Chao Peng
2022-07-20 15:31 ` Gupta, Pankaj
2022-07-20 16:21 ` Sean Christopherson
2022-07-20 17:41 ` Gupta, Pankaj
2022-07-21 7:34 ` Wei Wang
2022-07-21 9:29 ` Chao Peng
2022-07-21 17:58 ` Sean Christopherson
2022-07-25 13:04 ` Chao Peng
2022-07-29 19:54 ` Sean Christopherson
2022-08-02 0:49 ` Sean Christopherson
2022-08-02 16:38 ` Sean Christopherson
2022-08-03 9:48 ` Chao Peng
2022-08-03 15:51 ` Sean Christopherson
2022-08-04 7:58 ` Chao Peng
2022-07-20 16:44 ` Sean Christopherson
2022-07-21 9:37 ` Chao Peng
2022-08-19 19:37 ` Vishal Annapurve
2022-08-24 10:37 ` Chao Peng
2022-08-26 15:19 ` Fuad Tabba
2022-08-29 15:21 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 12/14] KVM: Handle page fault for private memory Chao Peng
2022-07-29 20:58 ` Sean Christopherson
2022-08-03 9:52 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 13/14] KVM: Enable and expose KVM_MEM_PRIVATE Chao Peng
2022-07-19 9:55 ` Gupta, Pankaj
2022-07-19 14:12 ` Chao Peng
2022-07-06 8:20 ` [PATCH v7 14/14] memfd_create.2: Describe MFD_INACCESSIBLE flag Chao Peng
2022-08-01 14:40 ` Dave Hansen
2022-08-03 9:53 ` Chao Peng
2022-07-13 3:58 ` [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory Gupta, Pankaj
2022-07-13 7:57 ` Chao Peng
2022-07-13 10:35 ` Gupta, Pankaj
2022-07-13 23:59 ` Chao Peng
2022-07-14 4:39 ` Gupta, Pankaj
2022-07-14 5:06 ` Gupta, Pankaj
2022-07-14 4:29 ` Andy Lutomirski
2022-07-14 5:13 ` Gupta, Pankaj
2022-08-11 10:02 ` Nikunj A. Dadhania
2022-08-11 11:30 ` Gupta, Pankaj
2022-08-11 13:32 ` Chao Peng
2022-08-11 17:28 ` Nikunj A. Dadhania
2022-08-12 3:22 ` Nikunj A. Dadhania
2022-08-11 17:18 ` Nikunj A. Dadhania
2022-08-11 23:02 ` Gupta, Pankaj
2022-08-12 6:02 ` Gupta, Pankaj
2022-08-12 7:18 ` Gupta, Pankaj
2022-08-12 8:48 ` Nikunj A. Dadhania
2022-08-12 9:33 ` Gupta, Pankaj
2022-08-15 13:04 ` Chao Peng
2022-08-16 4:28 ` Nikunj A. Dadhania
2022-08-16 11:33 ` Gupta, Pankaj
2022-08-16 12:24 ` Kirill A . Shutemov
2022-08-16 13:03 ` Gupta, Pankaj
2022-08-16 15:38 ` Sean Christopherson
2022-08-17 15:27 ` Michael Roth
2022-08-23 1:25 ` Isaku Yamahata
2022-08-23 17:41 ` Gupta, Pankaj
2022-08-18 5:40 ` Hugh Dickins
2022-08-18 13:24 ` Kirill A . Shutemov
2022-08-19 0:20 ` Sean Christopherson
2022-08-19 3:38 ` Hugh Dickins
2022-08-19 22:53 ` Sean Christopherson
2022-08-23 7:55 ` David Hildenbrand
2022-08-23 16:05 ` Sean Christopherson
2022-08-24 9:41 ` Chao Peng
2022-09-09 4:55 ` Andy Lutomirski
2022-08-19 3:00 ` Hugh Dickins
2022-08-20 0:27 ` Kirill A. Shutemov
2022-08-21 5:15 ` Hugh Dickins
2022-08-31 14:24 ` Kirill A . Shutemov
2022-09-02 10:27 ` Chao Peng
2022-09-02 12:30 ` Kirill A . Shutemov
2022-09-08 1:10 ` Kirill A. Shutemov
2022-09-13 9:44 ` Sean Christopherson
2022-09-13 13:28 ` Kirill A. Shutemov
2022-09-13 14:53 ` Sean Christopherson
2022-09-13 16:00 ` Kirill A. Shutemov
2022-09-13 16:12 ` Sean Christopherson
2022-09-09 4:48 ` Andy Lutomirski
2022-09-09 14:32 ` Kirill A . Shutemov
2022-09-09 19:11 ` Andy Lutomirski
2022-09-09 23:02 ` Kirill A . Shutemov
2022-08-21 10:27 ` Matthew Wilcox
2022-08-24 10:27 ` Chao Peng
2022-09-09 4:44 ` Andy Lutomirski
[not found] ` <diqzlej60z57.fsf@ackerleytng-cloudtop.c.googlers.com>
[not found] ` <20221202061347.1070246-2-chao.p.peng@linux.intel.com>
2023-04-13 15:25 ` Christian Brauner
2023-04-13 22:28 ` Sean Christopherson
2023-04-14 22:38 ` Ackerley Tng
2023-04-14 23:26 ` Sean Christopherson
2023-04-15 0:06 ` Sean Christopherson
2023-04-19 8:29 ` Christian Brauner
2023-04-20 0:49 ` Sean Christopherson
2023-04-20 8:35 ` Christian Brauner
2022-08-26 15:19 ` Fuad Tabba
2022-08-29 15:17 ` Chao Peng
2022-08-31 9:12 ` Fuad Tabba
2022-09-02 10:19 ` Chao Peng
2022-09-09 15:35 ` Michael Roth
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=203c752f-9439-b5ae-056c-27b2631dcb81@redhat.com \
--to=david@redhat.com \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=bfields@fieldses.org \
--cc=bp@alien8.de \
--cc=chao.p.peng@linux.intel.com \
--cc=corbet@lwn.net \
--cc=dave.hansen@intel.com \
--cc=ddutile@redhat.com \
--cc=dhildenb@redhat.com \
--cc=hpa@zytor.com \
--cc=hughd@google.com \
--cc=jlayton@kernel.org \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=jun.nakajima@intel.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mail@maciej.szmigiero.name \
--cc=mhocko@suse.com \
--cc=michael.roth@amd.com \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=qperret@google.com \
--cc=rppt@kernel.org \
--cc=seanjc@google.com \
--cc=shuah@kernel.org \
--cc=songmuchun@bytedance.com \
--cc=steven.price@arm.com \
--cc=tglx@linutronix.de \
--cc=vannapurve@google.com \
--cc=vbabka@suse.cz \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
--cc=yu.c.zhang@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox