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* [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory
@ 2022-07-06  8:20 Chao Peng
  2022-07-06  8:20 ` [PATCH v7 01/14] mm: Add F_SEAL_AUTO_ALLOCATE seal to memfd Chao Peng
                   ` (18 more replies)
  0 siblings, 19 replies; 354+ messages in thread
From: Chao Peng @ 2022-07-06  8:20 UTC (permalink / raw)
  To: kvm, linux-kernel, linux-mm, linux-fsdevel, linux-api, linux-doc,
	qemu-devel, linux-kselftest
  Cc: Paolo Bonzini, Jonathan Corbet, Sean Christopherson,
	Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
	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, Chao Peng, Kirill A . Shutemov, luto, jun.nakajima,
	dave.hansen, ak, david, aarcange, ddutile, dhildenb,
	Quentin Perret, Michael Roth, mhocko, Muchun Song

This is the v7 of this series which tries to implement the fd-based KVM
guest private memory. The patches are based on latest kvm/queue branch
commit:

  b9b71f43683a (kvm/queue) KVM: x86/mmu: Buffer nested MMU
split_desc_cache only by default capacity

Introduction
------------
In general this patch series introduce fd-based memslot which provides
guest memory through memory file descriptor fd[offset,size] instead of
hva/size. The fd can be created from a supported memory filesystem
like tmpfs/hugetlbfs etc. which we refer as memory backing store. KVM
and the the memory backing store exchange callbacks when such memslot
gets created. At runtime KVM will call into callbacks provided by the
backing store to get the pfn with the fd+offset. Memory backing store
will also call into KVM callbacks when userspace punch hole on the fd
to notify KVM to unmap secondary MMU page table entries.

Comparing to existing hva-based memslot, this new type of memslot allows
guest memory unmapped from host userspace like QEMU and even the kernel
itself, therefore reduce attack surface and prevent bugs.

Based on this fd-based memslot, we can build guest private memory that
is going to be used in confidential computing environments such as Intel
TDX and AMD SEV. When supported, the memory backing store can provide
more enforcement on the fd and KVM can use a single memslot to hold both
the private and shared part of the guest memory. 

mm extension
---------------------
Introduces new MFD_INACCESSIBLE flag for memfd_create(), the file
created with these flags cannot read(), write() or mmap() etc via normal
MMU operations. The file content can only be used with the newly
introduced memfile_notifier extension.

The memfile_notifier extension provides two sets of callbacks for KVM to
interact with the memory backing store:
  - memfile_notifier_ops: callbacks for memory backing store to notify
    KVM when memory gets invalidated.
  - backing store callbacks: callbacks for KVM to call into memory
    backing store to request memory pages for guest private memory.

The memfile_notifier extension also provides APIs for memory backing
store to register/unregister itself and to trigger the notifier when the
bookmarked memory gets invalidated.

The patchset also introduces a new memfd seal F_SEAL_AUTO_ALLOCATE to
prevent double allocation caused by unintentional guest when we only
have a single side of the shared/private memfds effective.

memslot extension
-----------------
Add the private fd and the fd offset to existing 'shared' memslot so
that both private/shared guest memory can live in one single memslot.
A page in the memslot is either private or shared. Whether a guest page
is private or shared is maintained through reusing existing SEV ioctls
KVM_MEMORY_ENCRYPT_{UN,}REG_REGION.

Test
----
To test the new functionalities of this patch TDX patchset is needed.
Since TDX patchset has not been merged so I did two kinds of test:

-  Regresion test on kvm/queue (this patchset)
   Most new code are not covered. Code also in below repo:
   https://github.com/chao-p/linux/tree/privmem-v7

-  New Funational test on latest TDX code
   The patch is rebased to latest TDX code and tested the new
   funcationalities. See below repos:
   Linux: https://github.com/chao-p/linux/tree/privmem-v7-tdx
   QEMU: https://github.com/chao-p/qemu/tree/privmem-v7

An example QEMU command line for TDX test:
-object tdx-guest,id=tdx,debug=off,sept-ve-disable=off \
-machine confidential-guest-support=tdx \
-object memory-backend-memfd-private,id=ram1,size=${mem} \
-machine memory-backend=ram1

Changelog
----------
v7:
  - Move the private/shared info from backing store to KVM.
  - Introduce F_SEAL_AUTO_ALLOCATE to avoid double allocation.
  - Rework on the sync mechanism between zap/page fault paths.
  - Addressed other comments in v6.
v6:
  - Re-organzied patch for both mm/KVM parts.
  - Added flags for memfile_notifier so its consumers can state their
    features and memory backing store can check against these flags.
  - Put a backing store reference in the memfile_notifier and move pfn_ops
    into backing store.
  - Only support boot time backing store register.
  - Overall KVM part improvement suggested by Sean and some others.
v5:
  - Removed userspace visible F_SEAL_INACCESSIBLE, instead using an
    in-kernel flag (SHM_F_INACCESSIBLE for shmem). Private fd can only
    be created by MFD_INACCESSIBLE.
  - Introduced new APIs for backing store to register itself to
    memfile_notifier instead of direct function call.
  - Added the accounting and restriction for MFD_INACCESSIBLE memory.
  - Added KVM API doc for new memslot extensions and man page for the new
    MFD_INACCESSIBLE flag.
  - Removed the overlap check for mapping the same file+offset into
    multiple gfns due to perf consideration, warned in document.
  - Addressed other comments in v4.
v4:
  - Decoupled the callbacks between KVM/mm from memfd and use new
    name 'memfile_notifier'.
  - Supported register multiple memslots to the same backing store.
  - Added per-memslot pfn_ops instead of per-system.
  - Reworked the invalidation part.
  - Improved new KVM uAPIs (private memslot extension and memory
    error) per Sean's suggestions.
  - Addressed many other minor fixes for comments from v3.
v3:
  - Added locking protection when calling
    invalidate_page_range/fallocate callbacks.
  - Changed memslot structure to keep use useraddr for shared memory.
  - Re-organized F_SEAL_INACCESSIBLE and MEMFD_OPS.
  - Added MFD_INACCESSIBLE flag to force F_SEAL_INACCESSIBLE.
  - Commit message improvement.
  - Many small fixes for comments from the last version.

Links to previous discussions
-----------------------------
[1] Original design proposal:
https://lkml.kernel.org/kvm/20210824005248.200037-1-seanjc@google.com/
[2] Updated proposal and RFC patch v1:
https://lkml.kernel.org/linux-fsdevel/20211111141352.26311-1-chao.p.peng@linux.intel.com/
[3] Patch v5: https://lkml.org/lkml/2022/5/19/861

Chao Peng (12):
  mm: Add F_SEAL_AUTO_ALLOCATE seal to memfd
  selftests/memfd: Add tests for F_SEAL_AUTO_ALLOCATE
  mm: Introduce memfile_notifier
  mm/memfd: Introduce MFD_INACCESSIBLE flag
  KVM: Rename KVM_PRIVATE_MEM_SLOTS to KVM_INTERNAL_MEM_SLOTS
  KVM: Use gfn instead of hva for mmu_notifier_retry
  KVM: Rename mmu_notifier_*
  KVM: Extend the memslot to support fd-based private memory
  KVM: Add KVM_EXIT_MEMORY_FAULT exit
  KVM: Register/unregister the guest private memory regions
  KVM: Handle page fault for private memory
  KVM: Enable and expose KVM_MEM_PRIVATE

Kirill A. Shutemov (1):
  mm/shmem: Support memfile_notifier

 Documentation/virt/kvm/api.rst             |  77 +++++-
 arch/arm64/kvm/mmu.c                       |   8 +-
 arch/mips/include/asm/kvm_host.h           |   2 +-
 arch/mips/kvm/mmu.c                        |  10 +-
 arch/powerpc/include/asm/kvm_book3s_64.h   |   2 +-
 arch/powerpc/kvm/book3s_64_mmu_host.c      |   4 +-
 arch/powerpc/kvm/book3s_64_mmu_hv.c        |   4 +-
 arch/powerpc/kvm/book3s_64_mmu_radix.c     |   6 +-
 arch/powerpc/kvm/book3s_hv_nested.c        |   2 +-
 arch/powerpc/kvm/book3s_hv_rm_mmu.c        |   8 +-
 arch/powerpc/kvm/e500_mmu_host.c           |   4 +-
 arch/riscv/kvm/mmu.c                       |   4 +-
 arch/x86/include/asm/kvm_host.h            |   3 +-
 arch/x86/kvm/Kconfig                       |   3 +
 arch/x86/kvm/mmu.h                         |   2 -
 arch/x86/kvm/mmu/mmu.c                     |  74 +++++-
 arch/x86/kvm/mmu/mmu_internal.h            |  18 ++
 arch/x86/kvm/mmu/mmutrace.h                |   1 +
 arch/x86/kvm/mmu/paging_tmpl.h             |   4 +-
 arch/x86/kvm/x86.c                         |   2 +-
 include/linux/kvm_host.h                   | 105 +++++---
 include/linux/memfile_notifier.h           |  91 +++++++
 include/linux/shmem_fs.h                   |   2 +
 include/uapi/linux/fcntl.h                 |   1 +
 include/uapi/linux/kvm.h                   |  37 +++
 include/uapi/linux/memfd.h                 |   1 +
 mm/Kconfig                                 |   4 +
 mm/Makefile                                |   1 +
 mm/memfd.c                                 |  18 +-
 mm/memfile_notifier.c                      | 123 ++++++++++
 mm/shmem.c                                 | 125 +++++++++-
 tools/testing/selftests/memfd/memfd_test.c | 166 +++++++++++++
 virt/kvm/Kconfig                           |   3 +
 virt/kvm/kvm_main.c                        | 272 ++++++++++++++++++---
 virt/kvm/pfncache.c                        |  14 +-
 35 files changed, 1074 insertions(+), 127 deletions(-)
 create mode 100644 include/linux/memfile_notifier.h
 create mode 100644 mm/memfile_notifier.c

-- 
2.25.1


^ permalink raw reply	[flat|nested] 354+ messages in thread
* [PATCH v10 0/9] KVM: mm: fd-based approach for supporting KVM
@ 2022-12-02  6:13 Chao Peng
  2022-12-02  6:13 ` [PATCH v10 1/9] mm: Introduce memfd_restricted system call to create restricted user memory Chao Peng
                   ` (10 more replies)
  0 siblings, 11 replies; 354+ messages in thread
From: Chao Peng @ 2022-12-02  6:13 UTC (permalink / raw)
  To: kvm, linux-kernel, linux-mm, linux-fsdevel, linux-arch,
	linux-api, linux-doc, qemu-devel
  Cc: Paolo Bonzini, Jonathan Corbet, Sean Christopherson,
	Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, Arnd Bergmann,
	Naoya Horiguchi, Miaohe Lin, x86, 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, Chao Peng,
	Kirill A . Shutemov, luto, jun.nakajima, dave.hansen, ak, david,
	aarcange, ddutile, dhildenb, Quentin Perret, tabba, Michael Roth,
	mhocko, wei.w.wang

This patch series implements KVM guest private memory for confidential
computing scenarios like Intel TDX[1]. If a TDX host accesses
TDX-protected guest memory, machine check can happen which can further
crash the running host system, this is terrible for multi-tenant
configurations. The host accesses include those from KVM userspace like
QEMU. This series addresses KVM userspace induced crash by introducing
new mm and KVM interfaces so KVM userspace can still manage guest memory
via a fd-based approach, but it can never access the guest memory
content.

The patch series touches both core mm and KVM code. I appreciate
Andrew/Hugh and Paolo/Sean can review and pick these patches. Any other
reviews are always welcome.
  - 01: mm change, target for mm tree
  - 02-09: KVM change, target for KVM tree

Given KVM is the only current user for the mm part, I have chatted with
Paolo and he is OK to merge the mm change through KVM tree, but
reviewed-by/acked-by is still expected from the mm people.

The patches have been verified with Intel TDX environment, but Vishal
has done an excellent work on the selftests[4] which are dedicated for
this series, making it possible to test this series without innovative
hardware and fancy steps of building a VM environment. See Test section
below for more info.


Introduction
============
KVM userspace being able to crash the host is horrible. Under current
KVM architecture, all guest memory is inherently accessible from KVM
userspace and is exposed to the mentioned crash issue. The goal of this
series is to provide a solution to align mm and KVM, on a userspace
inaccessible approach of exposing guest memory. 

Normally, KVM populates secondary page table (e.g. EPT) by using a host
virtual address (hva) from core mm page table (e.g. x86 userspace page
table). This requires guest memory being mmaped into KVM userspace, but
this is also the source where the mentioned crash issue can happen. In
theory, apart from those 'shared' memory for device emulation etc, guest
memory doesn't have to be mmaped into KVM userspace.

This series introduces fd-based guest memory which will not be mmaped
into KVM userspace. KVM populates secondary page table by using a
fd/offset pair backed by a memory file system. The fd can be created
from a supported memory filesystem like tmpfs/hugetlbfs and KVM can
directly interact with them with newly introduced in-kernel interface,
therefore remove the KVM userspace from the path of accessing/mmaping
the guest memory. 

Kirill had a patch [2] to address the same issue in a different way. It
tracks guest encrypted memory at the 'struct page' level and relies on
HWPOISON to reject the userspace access. The patch has been discussed in
several online and offline threads and resulted in a design document [3]
which is also the original proposal for this series. Later this patch
series evolved as more comments received in community but the major
concepts in [3] still hold true so recommend reading.

The patch series may also be useful for other usages, for example, pure
software approach may use it to harden itself against unintentional
access to guest memory. This series is designed with these usages in
mind but doesn't have code directly support them and extension might be
needed.


mm change
=========
Introduces a new memfd_restricted system call which can create memory
file that is restricted from userspace access via normal MMU operations
like read(), write() or mmap() etc and the only way to use it is
passing it to a third kernel module like KVM and relying on it to
access the fd through the newly added restrictedmem kernel interface.
The restrictedmem interface bridges the memory file subsystems
(tmpfs/hugetlbfs etc) and their users (KVM in this case) and provides
bi-directional communication between them. 


KVM change
==========
Extends the KVM memslot to provide guest private (encrypted) memory from
a fd. With this extension, a single memslot can maintain both private
memory through private fd (restricted_fd/restricted_offset) and shared
(unencrypted) memory through userspace mmaped host virtual address
(userspace_addr). For a particular guest page, the corresponding page in
KVM memslot can be only either private or shared and only one of the
shared/private parts of the memslot is visible to guest. For how this
new extension is used in QEMU, please refer to kvm_set_phys_mem() in
below TDX-enabled QEMU repo.

Introduces new KVM_EXIT_MEMORY_FAULT exit to allow userspace to get the
chance on decision-making for shared <-> private memory conversion. The
exit can be an implicit conversion in KVM page fault handler or an
explicit conversion from guest OS.

Introduces new KVM ioctl KVM_SET_MEMORY_ATTRIBUTES to maintain whether a
page is private or shared. This ioctl allows userspace to convert a page
between private <-> shared. The data maintained tells the truth whether
a guest page is private or shared and this information will be used in
KVM page fault handler to decide whether the private or the shared part
of the memslot is visible to guest.


Test
====
Ran two kinds of tests:
  - Selftests [4] from Vishal and VM boot tests in non-TDX environment
    Code also in below repo: https://github.com/chao-p/linux/tree/privmem-v10

  - Functional tests in TDX capable environment
    Tested the new functionalities in TDX environment. Code repos:
    Linux: https://github.com/chao-p/linux/tree/privmem-v10-tdx
    QEMU: https://github.com/chao-p/qemu/tree/privmem-v10

    An example QEMU command line for TDX test:
    -object tdx-guest,id=tdx,debug=off,sept-ve-disable=off \
    -machine confidential-guest-support=tdx \
    -object memory-backend-memfd-private,id=ram1,size=${mem} \
    -machine memory-backend=ram1


TODO
====
  - Page accounting and limiting for encrypted memory
  - hugetlbfs support


Changelog
=========
v10:
  - mm: hook up restricted_memfd to memory failure and route it to
    kernel users through .error() callback.
  - mm: call invalidate() notifier only for FALLOC_FL_PUNCH_HOLE, i.e.
    not for allocation.
  - KVM: introduce new ioctl KVM_SET_MEMORY_ATTRIBUTES for memory
    conversion instead of reusing KVM_MEMORY_ENCRYPT_{UN,}REG_REGION.
  - KVM: refine gfn-based mmu_notifier_retry() mechanism.
  - KVM: improve lpage_info updating code.
  - KVM: fix the bug in private memory handling that a private fault may
    fall into a non-private memslot.
  - KVM: handle memory machine check error for fd-based memory.
v9:
  - mm: move inaccessible memfd into separated syscall.
  - mm: return page instead of pfn_t for inaccessible_get_pfn and remove
    inaccessible_put_pfn.
  - KVM: rename inaccessible/private to restricted and CONFIG change to
    make the code friendly to pKVM.
  - KVM: add invalidate_begin/end pair to fix race contention and revise
    the lock protection for invalidation path.
  - KVM: optimize setting lpage_info for > 2M level by direct accessing
    lower level's result.
  - KVM: avoid load xarray in kvm_mmu_max_mapping_level() and instead let
    the caller to pass in is_private.
  - KVM: API doc improvement.
v8:
  - mm: redesign mm part by introducing a shim layer(inaccessible_memfd)
    in memfd to avoid touch the memory file systems directly.
  - mm: exclude F_SEAL_AUTO_ALLOCATE as it is for shared memory and
    cause confusion in this series, will send out separately.
  - doc: exclude the man page change, it's not kernel patch and will
    send out separately.
  - KVM: adapt to use the new mm inaccessible_memfd interface.
  - KVM: update lpage_info when setting mem_attr_array to support
    large page.
  - KVM: change from xa_store_range to xa_store for mem_attr_array due
    to xa_store_range overrides all entries which is not intended
    behavior for us.
  - KVM: refine the mmu_invalidate_retry_gfn mechanism for private page.
  - KVM: reorganize KVM_MEMORY_ENCRYPT_{UN,}REG_REGION and private page
    handling code suggested by Sean.
v7:
  - mm: introduce F_SEAL_AUTO_ALLOCATE to avoid double allocation.
  - KVM: use KVM_MEMORY_ENCRYPT_{UN,}REG_REGION to record
    private/shared info.
  - KVM: use similar sync mechanism between zap/page fault paths as
    mmu_notifier for memfile_notifier based invalidation.
v6:
  - mm: introduce MEMFILE_F_* flags into memfile_node to allow checking
    feature consistence among all memfile_notifier users and get rid of
    internal flags like SHM_F_INACCESSIBLE.
  - mm: make pfn_ops callbacks being members of memfile_backing_store
    and then refer to it directly in memfile_notifier.
  - mm: remove backing store unregister.
  - mm: remove RLIMIT_MEMLOCK based memory accounting and limiting.
  - KVM: reorganize patch sequence for page fault handling and private
    memory enabling.
v5:
  - Add man page for MFD_INACCESSIBLE flag and improve KVM API do for
    the new memslot extensions.
  - mm: introduce memfile_{un}register_backing_store to allow memory
    backing store to register/unregister it from memfile_notifier.
  - mm: remove F_SEAL_INACCESSIBLE, use in-kernel flag
    (SHM_F_INACCESSIBLE for shmem) instead. 
  - mm: add memory accounting and limiting (RLIMIT_MEMLOCK based) for
    MFD_INACCESSIBLE memory.
  - KVM: remove the overlap check for mapping the same file+offset into
    multiple gfns due to perf consideration, warned in document.
v4:
  - mm: rename memfd_ops to memfile_notifier and separate it from
    memfd.c to standalone memfile-notifier.c.
  - KVM: move pfn_ops to per-memslot scope from per-vm scope and allow
    registering multiple memslots to the same memory backing store.
  - KVM: add a 'kvm' reference in memslot so that we can recover kvm in
    memfile_notifier handlers.
  - KVM: add 'private_' prefix for the new fields in memslot.
  - KVM: reshape the 'type' to 'flag' for kvm_memory_exit
v3:
  - Remove 'RFC' prefix.
  - Fix race condition between memfile_notifier handlers and kvm destroy.
  - mm: introduce MFD_INACCESSIBLE flag for memfd_create() to force
    setting F_SEAL_INACCESSIBLE when the fd is created.
  - KVM: add the shared part of the memslot back to make private/shared
    pages live in one memslot.

Reference
=========
[1] Intel TDX:
https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html
[2] Kirill's implementation:
https://lore.kernel.org/all/20210416154106.23721-1-kirill.shutemov@linux.intel.com/T/ 
[3] Original design proposal:
https://lore.kernel.org/all/20210824005248.200037-1-seanjc@google.com/  
[4] Selftest:
https://lore.kernel.org/all/20221111014244.1714148-1-vannapurve@google.com/


Chao Peng (8):
  KVM: Introduce per-page memory attributes
  KVM: Extend the memslot to support fd-based private memory
  KVM: Add KVM_EXIT_MEMORY_FAULT exit
  KVM: Use gfn instead of hva for mmu_notifier_retry
  KVM: Unmap existing mappings when change the memory attributes
  KVM: Update lpage info when private/shared memory are mixed
  KVM: Handle page fault for private memory
  KVM: Enable and expose KVM_MEM_PRIVATE

Kirill A. Shutemov (1):
  mm: Introduce memfd_restricted system call to create restricted user
    memory

 Documentation/virt/kvm/api.rst         | 125 ++++++-
 arch/x86/entry/syscalls/syscall_32.tbl |   1 +
 arch/x86/entry/syscalls/syscall_64.tbl |   1 +
 arch/x86/include/asm/kvm_host.h        |   9 +
 arch/x86/kvm/Kconfig                   |   3 +
 arch/x86/kvm/mmu/mmu.c                 | 205 ++++++++++-
 arch/x86/kvm/mmu/mmu_internal.h        |  14 +-
 arch/x86/kvm/mmu/mmutrace.h            |   1 +
 arch/x86/kvm/mmu/tdp_mmu.c             |   2 +-
 arch/x86/kvm/x86.c                     |  17 +-
 include/linux/kvm_host.h               | 103 +++++-
 include/linux/restrictedmem.h          |  71 ++++
 include/linux/syscalls.h               |   1 +
 include/uapi/asm-generic/unistd.h      |   5 +-
 include/uapi/linux/kvm.h               |  53 +++
 include/uapi/linux/magic.h             |   1 +
 kernel/sys_ni.c                        |   3 +
 mm/Kconfig                             |   4 +
 mm/Makefile                            |   1 +
 mm/memory-failure.c                    |   3 +
 mm/restrictedmem.c                     | 318 +++++++++++++++++
 virt/kvm/Kconfig                       |   6 +
 virt/kvm/kvm_main.c                    | 469 +++++++++++++++++++++----
 23 files changed, 1323 insertions(+), 93 deletions(-)
 create mode 100644 include/linux/restrictedmem.h
 create mode 100644 mm/restrictedmem.c


base-commit: df0bb47baa95aad133820b149851d5b94cbc6790
-- 
2.25.1


^ permalink raw reply	[flat|nested] 354+ messages in thread
* [RFC PATCH v3 0/2] Providing mount in memfd_restricted() syscall
@ 2023-03-31 23:50 Ackerley Tng
  2023-03-31 23:50 ` [RFC PATCH v3 1/2] mm: restrictedmem: Allow userspace to specify mount for memfd_restricted Ackerley Tng
  2023-03-31 23:50 ` [RFC PATCH v3 2/2] selftests: restrictedmem: Check hugepage-ness of shmem file backing restrictedmem fd Ackerley Tng
  0 siblings, 2 replies; 354+ messages in thread
From: Ackerley Tng @ 2023-03-31 23:50 UTC (permalink / raw)
  To: kvm, linux-api, linux-arch, linux-doc, linux-fsdevel,
	linux-kernel, linux-mm, qemu-devel
  Cc: aarcange, ak, akpm, arnd, bfields, bp, chao.p.peng, corbet,
	dave.hansen, david, ddutile, dhildenb, hpa, hughd, jlayton,
	jmattson, joro, jun.nakajima, kirill.shutemov, linmiaohe, luto,
	mail, mhocko, michael.roth, mingo, naoya.horiguchi, pbonzini,
	qperret, rppt, seanjc, shuah, steven.price, tabba, tglx,
	vannapurve, vbabka, vkuznets, wanpengli, wei.w.wang, x86,
	yu.c.zhang, Ackerley Tng

Hello,

This patchset builds upon the memfd_restricted() system call that was
discussed in the ‘KVM: mm: fd-based approach for supporting KVM’ patch
series, at
https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@linux.intel.com/T/

The tree can be found at:
https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-provide-mount-fd-rfc-v3

In this patchset, a modification to the memfd_restricted() syscall is
proposed, which allows userspace to provide a mount, on which the
restrictedmem file will be created and returned from the
memfd_restricted().

Allowing userspace to provide a mount allows userspace to control
various memory binding policies via tmpfs mount options, such as
Transparent HugePage memory allocation policy through
‘huge=always/never’ and NUMA memory allocation policy through
‘mpol=local/bind:*’.

Changes since RFCv2:
+ Tightened semantics to accept only fds of the root of a tmpfs mount,
  as Christian suggested
+ Added permissions check on the inode represented by the fd to guard
  against creation of restrictedmem files on read-only tmpfs
  filesystems or mounts
+ Renamed RMFD_TMPFILE to RMFD_USERMNT to better represent providing a
  userspace mount to create a restrictedmem file on
+ Updated selftests for tighter semantics and added selftests to check
  for permissions

Changes since RFCv1:
+ Use fd to represent mount instead of path string, as Kirill
  suggested. I believe using fds makes this syscall interface more
  aligned with the other syscalls like fsopen(), fsconfig(), and
  fsmount() in terms of using and passing around fds
+ Remove unused variable char *orig_shmem_enabled from selftests

Dependencies:
+ Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting
  KVM’ patch series at
  https://github.com/sean-jc/linux/tree/x86/upm_base_support
+ Proposed fixes for these issues mentioned on the mailing list:
    + https://lore.kernel.org/lkml/diqzzga0fv96.fsf@ackerleytng-cloudtop-sg.c.googlers.com/

Links to earlier patch series:
+ RFC v2: https://lore.kernel.org/lkml/cover.1679428901.git.ackerleytng@google.com/T/
+ RFC v1: https://lore.kernel.org/lkml/cover.1676507663.git.ackerleytng@google.com/T/

---

Ackerley Tng (2):
  mm: restrictedmem: Allow userspace to specify mount for
    memfd_restricted
  selftests: restrictedmem: Check hugepage-ness of shmem file backing
    restrictedmem fd

 include/linux/syscalls.h                      |   2 +-
 include/uapi/linux/restrictedmem.h            |   8 +
 mm/restrictedmem.c                            |  74 ++-
 tools/testing/selftests/Makefile              |   1 +
 .../selftests/restrictedmem/.gitignore        |   3 +
 .../testing/selftests/restrictedmem/Makefile  |  15 +
 .../testing/selftests/restrictedmem/common.c  |   9 +
 .../testing/selftests/restrictedmem/common.h  |   8 +
 .../restrictedmem_hugepage_test.c             | 486 ++++++++++++++++++
 9 files changed, 599 insertions(+), 7 deletions(-)
 create mode 100644 include/uapi/linux/restrictedmem.h
 create mode 100644 tools/testing/selftests/restrictedmem/.gitignore
 create mode 100644 tools/testing/selftests/restrictedmem/Makefile
 create mode 100644 tools/testing/selftests/restrictedmem/common.c
 create mode 100644 tools/testing/selftests/restrictedmem/common.h
 create mode 100644 tools/testing/selftests/restrictedmem/restrictedmem_hugepage_test.c

--
2.40.0.348.gf938b09366-goog

^ permalink raw reply	[flat|nested] 354+ messages in thread

end of thread, other threads:[~2023-05-25  8:55 UTC | newest]

Thread overview: 354+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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
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
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
2022-12-02  6:13 [PATCH v10 0/9] KVM: mm: fd-based approach for supporting KVM Chao Peng
2022-12-02  6:13 ` [PATCH v10 1/9] mm: Introduce memfd_restricted system call to create restricted user memory Chao Peng
2022-12-06 14:57   ` Fuad Tabba
2022-12-07 13:50     ` Chao Peng
2022-12-13 23:49   ` Huang, Kai
2022-12-19  7:53     ` Chao Peng
2022-12-19  8:48       ` Huang, Kai
2022-12-20  7:22         ` Chao Peng
2022-12-20  8:33           ` Huang, Kai
2022-12-21 13:39             ` Chao Peng
2022-12-22  0:37               ` Huang, Kai
2022-12-23  8:20                 ` Chao Peng
2023-01-23 14:03                 ` Vlastimil Babka
2023-01-23 15:18                   ` Kirill A. Shutemov
2023-02-13 14:23                     ` Vlastimil Babka
2023-01-23 23:01                   ` Huang, Kai
2023-01-23 23:38                     ` Sean Christopherson
2023-01-24  7:51                       ` Vlastimil Babka
2022-12-22 18:15               ` Sean Christopherson
2022-12-23  0:50                 ` Huang, Kai
2022-12-23  8:24                 ` Chao Peng
2023-01-23 15:43                 ` Kirill A. Shutemov
2023-02-13 11:43                   ` Vlastimil Babka
2023-02-13 13:10                   ` Michael Roth
2023-01-13 21:54   ` Sean Christopherson
2023-01-17 12:41     ` Chao Peng
2023-01-17 16:34       ` Sean Christopherson
2023-01-18  8:16         ` Chao Peng
2023-01-18 10:17           ` Isaku Yamahata
2023-02-22  2:07     ` Alexey Kardashevskiy
2023-02-24  5:42       ` Chao Peng
2023-01-30  5:26   ` Ackerley Tng
2023-01-30  6:04     ` Wang, Wei W
2023-02-16  9:51   ` Nikunj A. Dadhania
2023-03-20 19:08     ` Michael Roth
2023-04-13 15:25   ` [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory 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
2023-04-13 17:22   ` [PATCH v10 1/9] mm: Introduce memfd_restricted system call to create restricted user memory Ackerley Tng
2022-12-02  6:13 ` [PATCH v10 2/9] KVM: Introduce per-page memory attributes Chao Peng
2022-12-06 13:34   ` Fabiano Rosas
2022-12-07 14:31     ` Chao Peng
2022-12-06 15:07   ` Fuad Tabba
2022-12-07 14:51     ` Chao Peng
2022-12-16 15:09   ` Borislav Petkov
2022-12-19  8:15     ` Chao Peng
2022-12-19 10:17       ` Borislav Petkov
2022-12-20  7:24         ` Chao Peng
2022-12-28  8:28   ` Chenyi Qiang
2023-01-03  1:39     ` Chao Peng
2023-01-03  3:32       ` Wang, Wei W
2023-01-03 23:06         ` Sean Christopherson
2023-01-05  4:39           ` Chao Peng
2023-01-13 22:02   ` Sean Christopherson
2023-01-17  3:21   ` Binbin Wu
2023-01-17 13:30     ` Chao Peng
2023-01-17 17:25       ` Sean Christopherson
2023-02-09  7:25   ` Isaku Yamahata
2023-02-10  0:35     ` Sean Christopherson
2023-02-13 23:53       ` Isaku Yamahata
2023-02-14 18:07         ` Sean Christopherson
2023-05-19 17:32   ` Nicolas Saenz Julienne
2023-05-19 18:23     ` Sean Christopherson
2023-05-19 19:49       ` Nicolas Saenz Julienne
2023-05-19 19:57         ` Sean Christopherson
2023-05-23 18:59       ` Nicolas Saenz Julienne
2022-12-02  6:13 ` [PATCH v10 3/9] KVM: Extend the memslot to support fd-based private memory Chao Peng
2022-12-05  9:03   ` Fuad Tabba
2022-12-06 11:53     ` Chao Peng
2022-12-06 12:39       ` Fuad Tabba
2022-12-07 15:10         ` Chao Peng
2022-12-08  8:37   ` Xiaoyao Li
2022-12-08 11:30     ` Chao Peng
2022-12-13 12:04       ` Xiaoyao Li
2022-12-19  7:50         ` Chao Peng
2022-12-19 14:36   ` Borislav Petkov
2022-12-20  7:43     ` Chao Peng
2022-12-20  9:55       ` Borislav Petkov
2022-12-21 13:42         ` Chao Peng
2023-01-05 11:23   ` Jarkko Sakkinen
2023-01-06  9:40     ` Chao Peng
2023-01-09 19:32       ` Sean Christopherson
2023-01-10  9:14         ` Chao Peng
2023-01-10 22:51           ` Vishal Annapurve
2023-01-13 22:37           ` Sean Christopherson
2023-01-17 12:42             ` Chao Peng
2023-01-20 23:42           ` Jarkko Sakkinen
2023-01-20 23:28         ` Jarkko Sakkinen
2022-12-02  6:13 ` [PATCH v10 4/9] KVM: Add KVM_EXIT_MEMORY_FAULT exit Chao Peng
2022-12-06 15:47   ` Fuad Tabba
2022-12-07 15:11     ` Chao Peng
2023-01-13 23:13   ` Sean Christopherson
2022-12-02  6:13 ` [PATCH v10 5/9] KVM: Use gfn instead of hva for mmu_notifier_retry Chao Peng
2022-12-05  9:23   ` Fuad Tabba
2022-12-06 11:56     ` Chao Peng
2022-12-06 15:48       ` Fuad Tabba
2022-12-09  6:24         ` Chao Peng
2022-12-07  6:34       ` Isaku Yamahata
2022-12-07 15:14         ` Chao Peng
2022-12-02  6:13 ` [PATCH v10 6/9] KVM: Unmap existing mappings when change the memory attributes Chao Peng
2022-12-07  8:13   ` Yuan Yao
2022-12-08 11:20     ` Chao Peng
2022-12-09  5:43       ` Yuan Yao
2022-12-07 17:16   ` Fuad Tabba
2022-12-08 11:13     ` Chao Peng
2022-12-09  8:57       ` Fuad Tabba
2022-12-12  7:22         ` Chao Peng
2022-12-13 23:51   ` Huang, Kai
2022-12-19  7:54     ` Chao Peng
2023-01-13 22:50   ` Sean Christopherson
2022-12-02  6:13 ` [PATCH v10 7/9] KVM: Update lpage info when private/shared memory are mixed Chao Peng
2022-12-05 22:49   ` Isaku Yamahata
2022-12-06 12:02     ` Chao Peng
2022-12-07  6:42       ` Isaku Yamahata
2022-12-08 11:17         ` Chao Peng
2023-01-13 23:12   ` Sean Christopherson
2023-01-13 23:16   ` Sean Christopherson
2023-01-28 13:54     ` Chao Peng
2022-12-02  6:13 ` [PATCH v10 8/9] KVM: Handle page fault for private memory Chao Peng
2022-12-08  2:29   ` Yuan Yao
2022-12-08 11:23     ` Chao Peng
2022-12-09  5:45       ` Yuan Yao
2022-12-09  9:01   ` Fuad Tabba
2022-12-12  7:23     ` Chao Peng
2023-01-13 23:29   ` Sean Christopherson
2022-12-02  6:13 ` [PATCH v10 9/9] KVM: Enable and expose KVM_MEM_PRIVATE Chao Peng
2022-12-09  9:11   ` Fuad Tabba
2023-01-05 20:38   ` Vishal Annapurve
2023-01-06  4:13     ` Chao Peng
2023-01-14  0:01   ` Sean Christopherson
2023-01-17 13:12     ` Chao Peng
2023-01-17 19:35       ` Sean Christopherson
2023-01-18  8:23         ` Chao Peng
2023-01-28 14:00     ` Chao Peng
2023-03-08  0:13       ` Ackerley Tng
2023-03-08  7:40         ` Chao Peng
2023-03-23  0:41           ` Isaku Yamahata
2023-03-24  2:10             ` Chao Peng
2023-03-24  2:29               ` Xiaoyao Li
2023-03-28 10:41                 ` Chao Peng
2023-04-14 21:08                   ` Sean Christopherson
2023-04-18 23:38                     ` Ackerley Tng
2023-04-25 23:01                       ` Sean Christopherson
2023-03-07 19:14   ` Ackerley Tng
2023-03-07 20:27     ` Sean Christopherson
2023-01-14  0:37 ` [PATCH v10 0/9] KVM: mm: fd-based approach for supporting KVM Sean Christopherson
2023-01-16 13:48   ` Kirill A. Shutemov
2023-01-17 13:19   ` Chao Peng
2023-01-17 14:32   ` Fuad Tabba
2023-01-19 11:13   ` Isaku Yamahata
2023-01-19 15:25     ` Sean Christopherson
2023-01-19 22:37       ` Isaku Yamahata
2023-01-24  1:27         ` Sean Christopherson
2023-02-08 12:24           ` Isaku Yamahata
2023-02-13 13:01           ` Michael Roth
2023-02-21 12:11             ` Chao Peng
2023-03-23  1:27               ` Michael Roth
2023-03-24  2:13                 ` Chao Peng
2023-04-12 22:01                 ` Sean Christopherson
2023-04-17 14:37           ` Chao Peng
2023-04-17 15:01             ` Sean Christopherson
2023-01-24 16:08   ` Liam Merwick
2023-01-25  0:20     ` Sean Christopherson
2023-01-25 12:53       ` Kirill A. Shutemov
2023-01-25 16:01         ` Liam Merwick
2023-04-13  1:07         ` Sean Christopherson
2023-04-13 16:04           ` Kirill A. Shutemov
2023-02-16  5:13 ` Mike Rapoport
2023-02-16  9:41   ` David Hildenbrand
2023-02-22 21:53     ` Sean Christopherson
2023-03-31 23:50 [RFC PATCH v3 0/2] Providing mount in memfd_restricted() syscall Ackerley Tng
2023-03-31 23:50 ` [RFC PATCH v3 1/2] mm: restrictedmem: Allow userspace to specify mount for memfd_restricted Ackerley Tng
2023-04-03  8:21   ` David Hildenbrand
2023-04-05 22:29     ` Ackerley Tng
2023-04-04  8:25   ` Kirill A. Shutemov
2023-04-05 22:32     ` Ackerley Tng
2023-04-04 13:53   ` Christian Brauner
2023-04-04 14:58     ` Christian Brauner
2023-04-05 21:58       ` Ackerley Tng
2023-04-12  9:59         ` Christian Brauner
2023-04-13 22:53           ` Ackerley Tng
2023-04-13 23:07             ` Sean Christopherson
2023-03-31 23:50 ` [RFC PATCH v3 2/2] selftests: restrictedmem: Check hugepage-ness of shmem file backing restrictedmem fd Ackerley Tng
2023-04-03  8:24   ` David Hildenbrand
2023-04-11  1:35     ` Ackerley Tng

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