Currently, guard regions are not visible to users except through
/proc/$pid/pagemap, with no explicit visibility at the VMA level.
This makes the feature less useful, as it isn't entirely apparent which
VMAs may have these entries present, especially when performing actions
which walk through memory regions such as those performed by CRIU.
This series addresses this issue by introducing the VM_MAYBE_GUARD flag
which fulfils this role, updating the smaps logic to display an entry for
these.
The semantics of this flag are that a guard region MAY be present if set
(we cannot be sure, as we can't efficiently track whether an
MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if
not set the VMA definitely does NOT have any guard regions present.
It's problematic to establish this flag without further action, because
that means that VMAs with guard regions in them become non-mergeable with
adjacent VMAs for no especially good reason.
To work around this, this series also introduces the concept of 'sticky'
VMA flags - that is flags which:
a. if set in one VMA and not in another still permit those VMAs to be
merged (if otherwise compatible).
b. When they are merged, the resultant VMA must have the flag set.
The VMA logic is updated to propagate these flags correctly.
Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve
an issue with file-backed guard regions - previously these established an
anon_vma object for file-backed mappings solely to have vma_needs_copy()
correctly propagate guard region mappings to child processes.
We introduce a new flag alias VM_COPY_ON_FORK (which currently only
specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly
for this flag and to copy page tables if it is present, which resolves this
issue.
Additionally, we add the ability for allow-listed VMA flags to be
atomically writable with only mmap/VMA read locks held.
The only flag we allow so far is VM_MAYBE_GUARD, which we carefully ensure
does not cause any races by being allowed to do so.
This allows us to maintain guard region installation as a read-locked
operation and not endure the overhead of obtaining a write lock here.
Finally we introduce extensive VMA userland tests to assert that the sticky
VMA logic behaves correctly as well as guard region self tests to assert
that smaps visibility is correctly implemented.
v4:
* Propagated tags, thanks all!
* Folded all fixups into series (thanks to Andrew for his patience with
these :)
* Added patch to correct an issue raised by Pedro - we can't
unconditionally set newflags |= vma->vm_flags because on split/noop we're
overwriting them.
* In new patch, corrected horrible formatting of vma_modify_*() while we
are here.
* In new patch, added kdoc as 3 kernel developers, including the author of
the code (!!) have been confused by this. Make explicitly clear what each
does.
* In new patch, make vm_flags_ptr parameter a pointer for vma_modify_flags,
and have the function correctly update the flags on merge, abstracting
this mess somewhat and avoiding case-by-case open-coding of the
fix. Describe clearly what's going on in the kdoc.
* Fixed typo reported by Jane and Liam, I must have been very tired... :)
* When introducing the new patch, we couldn't reference sticky VMA flags
yet as the concept had not yet been introduced. So update the patch that
introduces sticky flags to change the comments to reference the concept
now established.
v3:
* Propagated tags thanks Vlastimil & Pedro! :)
* Fixed doc nit as per Pedro.
* Added vma_flag_test_atomic() in preparation for fixing
retract_page_tables() (see below). We make this not require any locks, as
we serialise on the page table lock in retract_page_tables().
* Split the atomic flag enablement and actually setting the flag for guard
install into two separate commits so we clearly separate the various VMA
flag implementation details and us enabling this feature.
* Mentioned setting anon_vma for anonymous mappings in commit message as
per Vlastimil.
* Fixed an issue with retract_page_tables() whereby madvise(...,
MADV_COLLAPSE) relies upon file-backed VMAs not being collapsed due to
the UFFD WP VMA flag being set or the VMA having vma->anon_vma set
(i.e. being a MAP_PRIVATE file-backed VMA). This was updated to also
check for VM_MAYBE_GUARD.
* Introduced MADV_COLLAPSE self test to assert that the behaviour is
correct. I first reproduced the issue locally and then adapted the test
to assert that this no longer occurs.
* Mentioned KCSAN permissiveness in commit message as per Pedro.
* Mentioned mmap/VMA read lock excluding mmap/VMA write lock and thus
avoiding meaningful RMW races in commit message as per Vlastimil.
* Mentioned previous unconditional vma->anon_vma installation on guard
region installation as per Vlastimil.
* Avoided having merging compromised by reordering patches such that the
sticky VMA functionality is implemented prior to VM_MAYBE_GUARD being
utilised upon guard region installation, rendering Vlastimil's request to
mention this in a commit message unnecessary.
* Separated out sticky and copy on fork patches as per Pedro.
* Added VM_PFNMAP, VM_MIXEDMAP, VM_UFFD_WP to VM_COPY_ON_FORK to make
things more consistent and clean.
* Added mention of why generally VM_STICKY should be VM_COPY_ON_FORK in
copy on fork patch.
https://lore.kernel.org/all/cover.1762531708.git.lorenzo.stoakes@oracle.com/
v2:
* Separated out userland VMA tests for sticky behaviour as per Suren.
* Added the concept of atomic writable VMA flags as per Pedro and Vlastimil.
* Made VM_MAYBE_GUARD an atomic writable flag so we don't have to take a VMA
write lock in madvise() as per Pedro and Vlastimil.
https://lore.kernel.org/all/cover.1762422915.git.lorenzo.stoakes@oracle.com/
v1:
https://lore.kernel.org/all/cover.1761756437.git.lorenzo.stoakes@oracle.com/
Lorenzo Stoakes (9):
mm: introduce VM_MAYBE_GUARD and make visible in /proc/$pid/smaps
mm: add atomic VMA flags and set VM_MAYBE_GUARD as such
mm: update vma_modify_flags() to handle residual flags, document
mm: implement sticky VMA flags
mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one
mm: set the VM_MAYBE_GUARD flag on guard region install
tools/testing/vma: add VMA sticky userland tests
tools/testing/selftests/mm: add MADV_COLLAPSE test case
tools/testing/selftests/mm: add smaps visibility guard region test
Documentation/filesystems/proc.rst | 5 +-
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 101 +++++++++++
include/trace/events/mmflags.h | 1 +
mm/khugepaged.c | 71 +++++---
mm/madvise.c | 24 ++-
mm/memory.c | 14 +-
mm/mlock.c | 2 +-
mm/mprotect.c | 2 +-
mm/mseal.c | 9 +-
mm/vma.c | 78 +++++----
mm/vma.h | 138 +++++++++++----
tools/testing/selftests/mm/guard-regions.c | 185 +++++++++++++++++++++
tools/testing/selftests/mm/vm_util.c | 5 +
tools/testing/selftests/mm/vm_util.h | 1 +
tools/testing/vma/vma.c | 92 ++++++++--
tools/testing/vma/vma_internal.h | 55 ++++++
17 files changed, 650 insertions(+), 134 deletions(-)
--
2.51.2
I've removed the RFC tag from this version of the series, but the items
that I'm looking for feedback on remains the same:
- The userspace ABI, in particular:
- The vector length used for the SVE registers, access to the SVE
registers and access to ZA and (if available) ZT0 depending on
the current state of PSTATE.{SM,ZA}.
- The use of a single finalisation for both SVE and SME.
- The addition of control for enabling fine grained traps in a similar
manner to FGU but without the UNDEF, I'm not clear if this is desired
at all and at present this requires symmetric read and write traps like
FGU. That seemed like it might be desired from an implementation
point of view but we already have one case where we enable an
asymmetric trap (for ARM64_WORKAROUND_AMPERE_AC03_CPU_38) and it
seems generally useful to enable asymmetrically.
This series implements support for SME use in non-protected KVM guests.
Much of this is very similar to SVE, the main additional challenge that
SME presents is that it introduces a new vector length similar to the
SVE vector length and two new controls which change the registers seen
by guests:
- PSTATE.ZA enables the ZA matrix register and, if SME2 is supported,
the ZT0 LUT register.
- PSTATE.SM enables streaming mode, a new floating point mode which
uses the SVE register set with the separately configured SME vector
length. In streaming mode implementation of the FFR register is
optional.
It is also permitted to build systems which support SME without SVE, in
this case when not in streaming mode no SVE registers or instructions
are available. Further, there is no requirement that there be any
overlap in the set of vector lengths supported by SVE and SME in a
system, this is expected to be a common situation in practical systems.
Since there is a new vector length to configure we introduce a new
feature parallel to the existing SVE one with a new pseudo register for
the streaming mode vector length. Due to the overlap with SVE caused by
streaming mode rather than finalising SME as a separate feature we use
the existing SVE finalisation to also finalise SME, a new define
KVM_ARM_VCPU_VEC is provided to help make user code clearer. Finalising
SVE and SME separately would introduce complication with register access
since finalising SVE makes the SVE registers writeable by userspace and
doing multiple finalisations results in an error being reported.
Dealing with a state where the SVE registers are writeable due to one of
SVE or SME being finalised but may have their VL changed by the other
being finalised seems like needless complexity with minimal practical
utility, it seems clearer to just express directly that only one
finalisation can be done in the ABI.
Access to the floating point registers follows the architecture:
- When both SVE and SME are present:
- If PSTATE.SM == 0 the vector length used for the Z and P registers
is the SVE vector length.
- If PSTATE.SM == 1 the vector length used for the Z and P registers
is the SME vector length.
- If only SME is present:
- If PSTATE.SM == 0 the Z and P registers are inaccessible and the
floating point state accessed via the encodings for the V registers.
- If PSTATE.SM == 1 the vector length used for the Z and P registers
- The SME specific ZA and ZT0 registers are only accessible if SVCR.ZA is 1.
The VMM must understand this, in particular when loading state SVCR
should be configured before other state. It should be noted that while
the architecture refers to PSTATE.SM and PSTATE.ZA these PSTATE bits are
not preserved in SPSR_ELx, they are only accessible via SVCR.
There are a large number of subfeatures for SME, most of which only
offer additional instructions but some of which (SME2 and FA64) add
architectural state. These are configured via the ID registers as per
usual.
Protected KVM supported, with the implementation maintaining the
existing restriction that the hypervisor will refuse to run if streaming
mode or ZA is enabled. This both simplfies the code and avoids the need
to allocate storage for host ZA and ZT0 state, there seems to be little
practical use case for supporting this and the memory usage would be
non-trivial.
The new KVM_ARM_VCPU_VEC feature and ZA and ZT0 registers have not been
added to the get-reg-list selftest, the idea of supporting additional
features there without restructuring the program to generate all
possible feature combinations has been rejected. I will post a separate
series which does that restructuring.
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v9:
- Rebase onto v6.19-rc1.
- ABI document clarifications.
- Add changes dropping asserts on single bit wide bitfields in set_id_regs.
- Link to v8: https://lore.kernel.org/r/20250902-kvm-arm64-sme-v8-0-2cb2199c656c@kernel.o…
Changes in v8:
- Small fixes in ABI documentation.
- Link to v7: https://lore.kernel.org/r/20250822-kvm-arm64-sme-v7-0-7a65d82b8b10@kernel.o…
Changes in v7:
- Rebase onto v6.17-rc1.
- Handle SMIDR_EL1 as a VM wide ID register and use this in feat_sme_smps().
- Expose affinity fields in SMIDR_EL1.
- Remove SMPRI_EL1 from vcpu_sysreg, the value is always 0 currently.
- Prevent userspace writes to SMPRIMAP_EL2.
- Link to v6: https://lore.kernel.org/r/20250625-kvm-arm64-sme-v6-0-114cff4ffe04@kernel.o…
Changes in v6:
- Rebase onto v6.16-rc3.
- Link to v5: https://lore.kernel.org/r/20250417-kvm-arm64-sme-v5-0-f469a2d5f574@kernel.o…
Changes in v5:
- Rebase onto v6.15-rc2.
- Add pKVM guest support.
- Always restore SVCR.
- Link to v4: https://lore.kernel.org/r/20250214-kvm-arm64-sme-v4-0-d64a681adcc2@kernel.o…
Changes in v4:
- Rebase onto v6.14-rc2 and Mark Rutland's fixes.
- Expose SME to nested guests.
- Additional cleanups and test fixes following on from the rebase.
- Flush register state on VMM PSTATE.{SM,ZA}.
- Link to v3: https://lore.kernel.org/r/20241220-kvm-arm64-sme-v3-0-05b018c1ffeb@kernel.o…
Changes in v3:
- Rebase onto v6.12-rc2.
- Link to v2: https://lore.kernel.org/r/20231222-kvm-arm64-sme-v2-0-da226cb180bb@kernel.o…
Changes in v2:
- Rebase onto v6.7-rc3.
- Configure subfeatures based on host system only.
- Complete nVHE support.
- There was some snafu with sending v1 out, it didn't make it to the
lists but in case it hit people's inboxes I'm sending as v2.
---
Mark Brown (30):
arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06
arm64/fpsimd: Update FA64 and ZT0 enables when loading SME state
arm64/fpsimd: Decide to save ZT0 and streaming mode FFR at bind time
arm64/fpsimd: Check enable bit for FA64 when saving EFI state
arm64/fpsimd: Determine maximum virtualisable SME vector length
KVM: arm64: Pay attention to FFR parameter in SVE save and load
KVM: arm64: Pull ctxt_has_ helpers to start of sysreg-sr.h
KVM: arm64: Move SVE state access macros after feature test macros
KVM: arm64: Rename SVE finalization constants to be more general
KVM: arm64: Document the KVM ABI for SME
KVM: arm64: Define internal features for SME
KVM: arm64: Rename sve_state_reg_region
KVM: arm64: Store vector lengths in an array
KVM: arm64: Implement SME vector length configuration
KVM: arm64: Support SME control registers
KVM: arm64: Support TPIDR2_EL0
KVM: arm64: Support SME identification registers for guests
KVM: arm64: Support SME priority registers
KVM: arm64: Provide assembly for SME register access
KVM: arm64: Support userspace access to streaming mode Z and P registers
KVM: arm64: Flush register state on writes to SVCR.SM and SVCR.ZA
KVM: arm64: Expose SME specific state to userspace
KVM: arm64: Context switch SME state for guests
KVM: arm64: Handle SME exceptions
KVM: arm64: Expose SME to nested guests
KVM: arm64: Provide interface for configuring and enabling SME for guests
KVM: arm64: selftests: Remove spurious check for single bit safe values
KVM: arm64: selftests: Skip impossible invalid value tests
KVM: arm64: selftests: Add SME system registers to get-reg-list
KVM: arm64: selftests: Add SME to set_id_regs test
Documentation/virt/kvm/api.rst | 120 ++++++++---
arch/arm64/include/asm/fpsimd.h | 26 +++
arch/arm64/include/asm/kvm_emulate.h | 6 +
arch/arm64/include/asm/kvm_host.h | 163 ++++++++++++---
arch/arm64/include/asm/kvm_hyp.h | 5 +-
arch/arm64/include/asm/kvm_pkvm.h | 2 +-
arch/arm64/include/asm/vncr_mapping.h | 2 +
arch/arm64/include/uapi/asm/kvm.h | 33 +++
arch/arm64/kernel/cpufeature.c | 2 -
arch/arm64/kernel/fpsimd.c | 89 ++++----
arch/arm64/kvm/arm.c | 10 +
arch/arm64/kvm/config.c | 11 +-
arch/arm64/kvm/fpsimd.c | 28 ++-
arch/arm64/kvm/guest.c | 252 ++++++++++++++++++++---
arch/arm64/kvm/handle_exit.c | 14 ++
arch/arm64/kvm/hyp/fpsimd.S | 28 ++-
arch/arm64/kvm/hyp/include/hyp/switch.h | 168 +++++++++++++--
arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 110 ++++++----
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 86 ++++++--
arch/arm64/kvm/hyp/nvhe/pkvm.c | 85 ++++++--
arch/arm64/kvm/hyp/nvhe/switch.c | 4 +-
arch/arm64/kvm/hyp/nvhe/sys_regs.c | 6 +
arch/arm64/kvm/hyp/vhe/switch.c | 17 +-
arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 7 +
arch/arm64/kvm/nested.c | 3 +-
arch/arm64/kvm/reset.c | 156 ++++++++++----
arch/arm64/kvm/sys_regs.c | 140 ++++++++++++-
arch/arm64/tools/sysreg | 8 +-
include/uapi/linux/kvm.h | 1 +
tools/testing/selftests/kvm/arm64/get-reg-list.c | 15 +-
tools/testing/selftests/kvm/arm64/set_id_regs.c | 84 ++++++--
31 files changed, 1367 insertions(+), 314 deletions(-)
---
base-commit: 3e7f562e20ee87a25e104ef4fce557d39d62fa85
change-id: 20230301-kvm-arm64-sme-06a1246d3636
Best regards,
--
Mark Brown <broonie(a)kernel.org>
This series adds namespace support to vhost-vsock and loopback. It does
not add namespaces to any of the other guest transports (virtio-vsock,
hyperv, or vmci).
The current revision supports two modes: local and global. Local
mode is complete isolation of namespaces, while global mode is complete
sharing between namespaces of CIDs (the original behavior).
The mode is set using the parent namespace's
/proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
created. The mode of the current namespace can be queried by reading
/proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
has been created.
Modes are per-netns. This allows a system to configure namespaces
independently (some may share CIDs, others are completely isolated).
This also supports future possible mixed use cases, where there may be
namespaces in global mode spinning up VMs while there are mixed mode
namespaces that provide services to the VMs, but are not allowed to
allocate from the global CID pool (this mode is not implemented in this
series).
Additionally, added tests for the new namespace features:
tools/testing/selftests/vsock/vmtest.sh
1..25
ok 1 vm_server_host_client
ok 2 vm_client_host_server
ok 3 vm_loopback
ok 4 ns_host_vsock_ns_mode_ok
ok 5 ns_host_vsock_child_ns_mode_ok
ok 6 ns_global_same_cid_fails
ok 7 ns_local_same_cid_ok
ok 8 ns_global_local_same_cid_ok
ok 9 ns_local_global_same_cid_ok
ok 10 ns_diff_global_host_connect_to_global_vm_ok
ok 11 ns_diff_global_host_connect_to_local_vm_fails
ok 12 ns_diff_global_vm_connect_to_global_host_ok
ok 13 ns_diff_global_vm_connect_to_local_host_fails
ok 14 ns_diff_local_host_connect_to_local_vm_fails
ok 15 ns_diff_local_vm_connect_to_local_host_fails
ok 16 ns_diff_global_to_local_loopback_local_fails
ok 17 ns_diff_local_to_global_loopback_fails
ok 18 ns_diff_local_to_local_loopback_fails
ok 19 ns_diff_global_to_global_loopback_ok
ok 20 ns_same_local_loopback_ok
ok 21 ns_same_local_host_connect_to_local_vm_ok
ok 22 ns_same_local_vm_connect_to_local_host_ok
ok 23 ns_delete_vm_ok
ok 24 ns_delete_host_ok
ok 25 ns_delete_both_ok
SUMMARY: PASS=25 SKIP=0 FAIL=0
Thanks again for everyone's help and reviews!
Suggested-by: Sargun Dhillon <sargun(a)sargun.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman(a)gmail.com>
Changes in v13:
- add support for immutable sysfs ns_mode and inheritance from sysfs child_ns_mode
- remove passing around of net_mode, can be accessed now via
vsock_net_mode(net) since it is immutable
- update tests for new uAPI
- add one patch to extend the kselftest timeout (it was starting to
fail with the new tests added)
- Link to v12: https://lore.kernel.org/r/20251126-vsock-vmtest-v12-0-257ee21cd5de@meta.com
Changes in v12:
- add ns mode checking to _allow() callbacks to reject local mode for
incompatible transports (Stefano)
- flip vhost/loopback to return true for stream_allow() and
seqpacket_allow() in "vsock: add netns support to virtio transports"
(Stefano)
- add VMADDR_CID_ANY + local mode documentation in af_vsock.c (Stefano)
- change "selftests/vsock: add tests for host <-> vm connectivity with
namespaces" to skip test 29 in vsock_test for namespace local
vsock_test calls in a host local-mode namespace. There is a
false-positive edge case for that test encountered with the
->stream_allow() approach. More details in that patch.
- updated cover letter with new test output
- Link to v11: https://lore.kernel.org/r/20251120-vsock-vmtest-v11-0-55cbc80249a7@meta.com
Changes in v11:
- vmtest: add a patch to use ss in wait_for_listener functions and
support vsock, tcp, and unix. Change all patches to use the new
functions.
- vmtest: add a patch to re-use vm dmesg / warn counting functions
- Link to v10: https://lore.kernel.org/r/20251117-vsock-vmtest-v10-0-df08f165bf3e@meta.com
Changes in v10:
- Combine virtio common patches into one (Stefano)
- Resolve vsock_loopback virtio_transport_reset_no_sock() issue
with info->vsk setting. This eliminates the need for skb->cb,
so remove skb->cb patches.
- many line width 80 fixes
- Link to v9: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-0-852787a37bed@meta.com
Changes in v9:
- reorder loopback patch after patch for virtio transport common code
- remove module ordering tests patch because loopback no longer depends
on pernet ops
- major simplifications in vsock_loopback
- added a new patch for blocking local mode for guests, added test case
to check
- add net ref tracking to vsock_loopback patch
- Link to v8: https://lore.kernel.org/r/20251023-vsock-vmtest-v8-0-dea984d02bb0@meta.com
Changes in v8:
- Break generic cleanup/refactoring patches into standalone series,
remove those from this series
- Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements…
- Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com
Changes in v7:
- fix hv_sock build
- break out vmtest patches into distinct, more well-scoped patches
- change `orig_net_mode` to `net_mode`
- many fixes and style changes in per-patch change sets (see individual
patches for specific changes)
- optimize `virtio_vsock_skb_cb` layout
- update commit messages with more useful descriptions
- vsock_loopback: use orig_net_mode instead of current net mode
- add tests for edge cases (ns deletion, mode changing, loopback module
load ordering)
- Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com
Changes in v6:
- define behavior when mode changes to local while socket/VM is alive
- af_vsock: clarify description of CID behavior
- af_vsock: use stronger langauge around CID rules (dont use "may")
- af_vsock: improve naming of buf/buffer
- af_vsock: improve string length checking on proc writes
- vsock_loopback: add space in struct to clarify lock protection
- vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit()
- vsock_loopback: use virtio_vsock_skb_net() instead of sock_net()
- vsock_loopback: set loopback to NULL after kfree()
- vsock_loopback: use pernet_operations and remove callback mechanism
- vsock_loopback: add macros for "global" and "local"
- vsock_loopback: fix length checking
- vmtest.sh: check for namespace support in vmtest.sh
- Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com
Changes in v5:
- /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode
- vsock_global_net -> vsock_global_dummy_net
- fix netns lookup in vhost_vsock to respect pid namespaces
- add callbacks for vsock_loopback to avoid circular dependency
- vmtest.sh loads vsock_loopback module
- remove vsock_net_mode_can_set()
- change vsock_net_write_mode() to return true/false based on success
- make vsock_net_mode enum instead of u8
- Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com
Changes in v4:
- removed RFC tag
- implemented loopback support
- renamed new tests to better reflect behavior
- completed suite of tests with permutations of ns modes and vsock_test
as guest/host
- simplified socat bridging with unix socket instead of tcp + veth
- only use vsock_test for success case, socat for failure case (context
in commit message)
- lots of cleanup
Changes in v3:
- add notion of "modes"
- add procfs /proc/net/vsock_ns_mode
- local and global modes only
- no /dev/vhost-vsock-netns
- vmtest.sh already merged, so new patch just adds new tests for NS
- Link to v2:
https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com
Changes in v2:
- only support vhost-vsock namespaces
- all g2h namespaces retain old behavior, only common API changes
impacted by vhost-vsock changes
- add /dev/vhost-vsock-netns for "opt-in"
- leave /dev/vhost-vsock to old behavior
- removed netns module param
- Link to v1:
https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com
Changes in v1:
- added 'netns' module param to vsock.ko to enable the
network namespace support (disabled by default)
- added 'vsock_net_eq()' to check the "net" assigned to a socket
only when 'netns' support is enabled
- Link to RFC: https://patchwork.ozlabs.org/cover/1202235/
---
Bobby Eshleman (13):
vsock: add per-net vsock NS mode state
vsock: add netns to vsock core
virtio: set skb owner of virtio_transport_reset_no_sock() reply
vsock: add netns support to virtio transports
selftests/vsock: increase timeout to 1200
selftests/vsock: add namespace helpers to vmtest.sh
selftests/vsock: prepare vm management helpers for namespaces
selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers
selftests/vsock: use ss to wait for listeners instead of /proc/net
selftests/vsock: add tests for proc sys vsock ns_mode
selftests/vsock: add namespace tests for CID collisions
selftests/vsock: add tests for host <-> vm connectivity with namespaces
selftests/vsock: add tests for namespace deletion
MAINTAINERS | 1 +
drivers/vhost/vsock.c | 44 +-
include/linux/virtio_vsock.h | 9 +-
include/net/af_vsock.h | 53 +-
include/net/net_namespace.h | 4 +
include/net/netns/vsock.h | 17 +
net/vmw_vsock/af_vsock.c | 296 ++++++++-
net/vmw_vsock/hyperv_transport.c | 7 +-
net/vmw_vsock/virtio_transport.c | 22 +-
net/vmw_vsock/virtio_transport_common.c | 62 +-
net/vmw_vsock/vmci_transport.c | 26 +-
net/vmw_vsock/vsock_loopback.c | 22 +-
tools/testing/selftests/vsock/settings | 2 +-
tools/testing/selftests/vsock/vmtest.sh | 1055 +++++++++++++++++++++++++++++--
14 files changed, 1487 insertions(+), 133 deletions(-)
---
base-commit: 962ac5ca99a5c3e7469215bf47572440402dfd59
change-id: 20250325-vsock-vmtest-b3a21d2102c2
prerequisite-message-id: <20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463(a)meta.com>
prerequisite-patch-id: a2eecc3851f2509ed40009a7cab6990c6d7cfff5
prerequisite-patch-id: 501db2100636b9c8fcb3b64b8b1df797ccbede85
prerequisite-patch-id: ba1a2f07398a035bc48ef72edda41888614be449
prerequisite-patch-id: fd5cc5445aca9355ce678e6d2bfa89fab8a57e61
prerequisite-patch-id: 795ab4432ffb0843e22b580374782e7e0d99b909
prerequisite-patch-id: 1499d263dc933e75366c09e045d2125ca39f7ddd
prerequisite-patch-id: f92d99bb1d35d99b063f818a19dcda999152d74c
prerequisite-patch-id: e3296f38cdba6d903e061cff2bbb3e7615e8e671
prerequisite-patch-id: bc4662b4710d302d4893f58708820fc2a0624325
prerequisite-patch-id: f8991f2e98c2661a706183fde6b35e2b8d9aedcf
prerequisite-patch-id: 44bf9ed69353586d284e5ee63d6fffa30439a698
prerequisite-patch-id: d50621bc630eeaf608bbaf260370c8dabf6326df
Best regards,
--
Bobby Eshleman <bobbyeshleman(a)meta.com>
The function get_desc64_base() performs a series of bitwise left shifts on
fields of various sizes. More specifically, when performing '<< 24' on
'desc->base2' (which is a u8), 'base2' is promoted to a signed integer
before shifting.
In a scenario where base2 >= 0x80, the shift places a 1 into bit 31,
causing the 32-bit intermediate value to become negative. When this
result is cast to uint64_t or ORed into the return value, sign extension
occurs, corrupting the upper 32 bits of the address (base3).
Example:
Given:
base0 = 0x5000
base1 = 0xd6
base2 = 0xf8
base3 = 0xfffffe7c
Expected return: 0xfffffe7cf8d65000
Actual return: 0xfffffffff8d65000
Fix this by explicitly casting the fields to 'uint64_t' before shifting
to prevent sign extension.
Signed-off-by: MJ Pooladkhay <mj(a)pooladkhay.com>
---
v2:
- Remove the intermediate 'low' variable and use a single return statement
as suggested by Sean Christopherson.
v1: https://lore.kernel.org/kvm/20251220021050.88490-1-mj@pooladkhay.com/
While using get_desc64_base() to set the HOST_TR_BASE value for a custom
educational hypervisor, I observed system freezes, either immediately or
after migrating the guest to a new core. I eventually realized that KVM
uses get_cpu_entry_area() for the TR base. Switching to that fixed my
freezes (which were triple faults on one core followed by soft lockups
on others, waiting on smp_call_function_many_cond) and helped me identify
the sign-extension bug in this helper function that was corrupting the
HOST_TR_BASE value.
Thanks,
MJ Pooladkhay
tools/testing/selftests/kvm/include/x86/processor.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index 57d62a425..26a91bb73 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -436,8 +436,10 @@ struct kvm_x86_state {
static inline uint64_t get_desc64_base(const struct desc64 *desc)
{
- return ((uint64_t)desc->base3 << 32) |
- (desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24));
+ return (uint64_t)desc->base3 << 32 |
+ (uint64_t)desc->base2 << 24 |
+ (uint64_t)desc->base1 << 16 |
+ (uint64_t)desc->base0;
}
static inline uint64_t rdtsc(void)
--
2.52.0
The IA32 Emulation support can be either removed from the kernel,
disabled by default or disabled at runtime. Some of x86 selftests
are crashing for all of above thus is_32bit_syscall_supported()
helper is added to skip int80 syscalls if they are not supported.
Slawomir Rosek (2):
selftests/x86/ldt_gdt: Skip int80 if not supported
selftests/x86/ptrace_syscall: Skip int80 if not supported
tools/testing/selftests/x86/ldt_gdt.c | 21 +++++++++++++++++++-
tools/testing/selftests/x86/ptrace_syscall.c | 20 +++++++++++++++++--
2 files changed, 38 insertions(+), 3 deletions(-)
--
2.52.0.305.g3fc767764a-goog
This series adds namespace support to vhost-vsock and loopback. It does
not add namespaces to any of the other guest transports (virtio-vsock,
hyperv, or vmci).
The current revision supports two modes: local and global. Local
mode is complete isolation of namespaces, while global mode is complete
sharing between namespaces of CIDs (the original behavior).
The mode is set using /proc/sys/net/vsock/ns_mode.
Modes are per-netns and write-once. This allows a system to configure
namespaces independently (some may share CIDs, others are completely
isolated). This also supports future possible mixed use cases, where
there may be namespaces in global mode spinning up VMs while there are
mixed mode namespaces that provide services to the VMs, but are not
allowed to allocate from the global CID pool (this mode is not
implemented in this series).
If a socket or VM is created when a namespace is global but the
namespace changes to local, the socket or VM will continue working
normally. That is, the socket or VM assumes the mode behavior of the
namespace at the time the socket/VM was created. The original mode is
captured in vsock_create() and so occurs at the time of socket(2) and
accept(2) for sockets and open(2) on /dev/vhost-vsock for VMs. This
prevents a socket/VM connection from suddenly breaking due to a
namespace mode change. Any new sockets/VMs created after the mode change
will adopt the new mode's behavior.
Additionally, added tests for the new namespace features:
tools/testing/selftests/vsock/vmtest.sh
1..28
ok 1 vm_server_host_client
ok 2 vm_client_host_server
ok 3 vm_loopback
ok 4 ns_host_vsock_ns_mode_ok
ok 5 ns_host_vsock_ns_mode_write_once_ok
ok 6 ns_global_same_cid_fails
ok 7 ns_local_same_cid_ok
ok 8 ns_global_local_same_cid_ok
ok 9 ns_local_global_same_cid_ok
ok 10 ns_diff_global_host_connect_to_global_vm_ok
ok 11 ns_diff_global_host_connect_to_local_vm_fails
ok 12 ns_diff_global_vm_connect_to_global_host_ok
ok 13 ns_diff_global_vm_connect_to_local_host_fails
ok 14 ns_diff_local_host_connect_to_local_vm_fails
ok 15 ns_diff_local_vm_connect_to_local_host_fails
ok 16 ns_diff_global_to_local_loopback_local_fails
ok 17 ns_diff_local_to_global_loopback_fails
ok 18 ns_diff_local_to_local_loopback_fails
ok 19 ns_diff_global_to_global_loopback_ok
ok 20 ns_same_local_loopback_ok
ok 21 ns_same_local_host_connect_to_local_vm_ok
ok 22 ns_same_local_vm_connect_to_local_host_ok
ok 23 ns_mode_change_connection_continue_vm_ok
ok 24 ns_mode_change_connection_continue_host_ok
ok 25 ns_mode_change_connection_continue_both_ok
ok 26 ns_delete_vm_ok
ok 27 ns_delete_host_ok
ok 28 ns_delete_both_ok
SUMMARY: PASS=28 SKIP=0 FAIL=0
Dependent on series:
https://lore.kernel.org/all/20251108-vsock-selftests-fixes-and-improvements…
Thanks again for everyone's help and reviews!
Suggested-by: Sargun Dhillon <sargun(a)sargun.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman(a)gmail.com>
Changes in v12:
- add ns mode checking to _allow() callbacks to reject local mode for
incompatible transports (Stefano)
- flip vhost/loopback to return true for stream_allow() and
seqpacket_allow() in "vsock: add netns support to virtio transports"
(Stefano)
- add VMADDR_CID_ANY + local mode documentation in af_vsock.c (Stefano)
- change "selftests/vsock: add tests for host <-> vm connectivity with
namespaces" to skip test 29 in vsock_test for namespace local
vsock_test calls in a host local-mode namespace. There is a
false-positive edge case for that test encountered with the
->stream_allow() approach. More details in that patch.
- updated cover letter with new test output
- Link to v11: https://lore.kernel.org/r/20251120-vsock-vmtest-v11-0-55cbc80249a7@meta.com
Changes in v11:
- vmtest: add a patch to use ss in wait_for_listener functions and
support vsock, tcp, and unix. Change all patches to use the new
functions.
- vmtest: add a patch to re-use vm dmesg / warn counting functions
- Link to v10: https://lore.kernel.org/r/20251117-vsock-vmtest-v10-0-df08f165bf3e@meta.com
Changes in v10:
- Combine virtio common patches into one (Stefano)
- Resolve vsock_loopback virtio_transport_reset_no_sock() issue
with info->vsk setting. This eliminates the need for skb->cb,
so remove skb->cb patches.
- many line width 80 fixes
- Link to v9: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-0-852787a37bed@meta.com
Changes in v9:
- reorder loopback patch after patch for virtio transport common code
- remove module ordering tests patch because loopback no longer depends
on pernet ops
- major simplifications in vsock_loopback
- added a new patch for blocking local mode for guests, added test case
to check
- add net ref tracking to vsock_loopback patch
- Link to v8: https://lore.kernel.org/r/20251023-vsock-vmtest-v8-0-dea984d02bb0@meta.com
Changes in v8:
- Break generic cleanup/refactoring patches into standalone series,
remove those from this series
- Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements…
- Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com
Changes in v7:
- fix hv_sock build
- break out vmtest patches into distinct, more well-scoped patches
- change `orig_net_mode` to `net_mode`
- many fixes and style changes in per-patch change sets (see individual
patches for specific changes)
- optimize `virtio_vsock_skb_cb` layout
- update commit messages with more useful descriptions
- vsock_loopback: use orig_net_mode instead of current net mode
- add tests for edge cases (ns deletion, mode changing, loopback module
load ordering)
- Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com
Changes in v6:
- define behavior when mode changes to local while socket/VM is alive
- af_vsock: clarify description of CID behavior
- af_vsock: use stronger langauge around CID rules (dont use "may")
- af_vsock: improve naming of buf/buffer
- af_vsock: improve string length checking on proc writes
- vsock_loopback: add space in struct to clarify lock protection
- vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit()
- vsock_loopback: use virtio_vsock_skb_net() instead of sock_net()
- vsock_loopback: set loopback to NULL after kfree()
- vsock_loopback: use pernet_operations and remove callback mechanism
- vsock_loopback: add macros for "global" and "local"
- vsock_loopback: fix length checking
- vmtest.sh: check for namespace support in vmtest.sh
- Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com
Changes in v5:
- /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode
- vsock_global_net -> vsock_global_dummy_net
- fix netns lookup in vhost_vsock to respect pid namespaces
- add callbacks for vsock_loopback to avoid circular dependency
- vmtest.sh loads vsock_loopback module
- remove vsock_net_mode_can_set()
- change vsock_net_write_mode() to return true/false based on success
- make vsock_net_mode enum instead of u8
- Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com
Changes in v4:
- removed RFC tag
- implemented loopback support
- renamed new tests to better reflect behavior
- completed suite of tests with permutations of ns modes and vsock_test
as guest/host
- simplified socat bridging with unix socket instead of tcp + veth
- only use vsock_test for success case, socat for failure case (context
in commit message)
- lots of cleanup
Changes in v3:
- add notion of "modes"
- add procfs /proc/net/vsock_ns_mode
- local and global modes only
- no /dev/vhost-vsock-netns
- vmtest.sh already merged, so new patch just adds new tests for NS
- Link to v2:
https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com
Changes in v2:
- only support vhost-vsock namespaces
- all g2h namespaces retain old behavior, only common API changes
impacted by vhost-vsock changes
- add /dev/vhost-vsock-netns for "opt-in"
- leave /dev/vhost-vsock to old behavior
- removed netns module param
- Link to v1:
https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com
Changes in v1:
- added 'netns' module param to vsock.ko to enable the
network namespace support (disabled by default)
- added 'vsock_net_eq()' to check the "net" assigned to a socket
only when 'netns' support is enabled
- Link to RFC: https://patchwork.ozlabs.org/cover/1202235/
---
Bobby Eshleman (12):
vsock: a per-net vsock NS mode state
vsock: add netns to vsock core
virtio: set skb owner of virtio_transport_reset_no_sock() reply
vsock: add netns support to virtio transports
selftests/vsock: add namespace helpers to vmtest.sh
selftests/vsock: prepare vm management helpers for namespaces
selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers
selftests/vsock: use ss to wait for listeners instead of /proc/net
selftests/vsock: add tests for proc sys vsock ns_mode
selftests/vsock: add namespace tests for CID collisions
selftests/vsock: add tests for host <-> vm connectivity with namespaces
selftests/vsock: add tests for namespace deletion and mode changes
MAINTAINERS | 1 +
drivers/vhost/vsock.c | 59 +-
include/linux/virtio_vsock.h | 12 +-
include/net/af_vsock.h | 57 +-
include/net/net_namespace.h | 4 +
include/net/netns/vsock.h | 17 +
net/vmw_vsock/af_vsock.c | 272 +++++++-
net/vmw_vsock/hyperv_transport.c | 7 +-
net/vmw_vsock/virtio_transport.c | 19 +-
net/vmw_vsock/virtio_transport_common.c | 75 ++-
net/vmw_vsock/vmci_transport.c | 26 +-
net/vmw_vsock/vsock_loopback.c | 23 +-
tools/testing/selftests/vsock/vmtest.sh | 1077 +++++++++++++++++++++++++++++--
13 files changed, 1522 insertions(+), 127 deletions(-)
---
base-commit: 962ac5ca99a5c3e7469215bf47572440402dfd59
change-id: 20250325-vsock-vmtest-b3a21d2102c2
prerequisite-message-id: <20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463(a)meta.com>
prerequisite-patch-id: a2eecc3851f2509ed40009a7cab6990c6d7cfff5
prerequisite-patch-id: 501db2100636b9c8fcb3b64b8b1df797ccbede85
prerequisite-patch-id: ba1a2f07398a035bc48ef72edda41888614be449
prerequisite-patch-id: fd5cc5445aca9355ce678e6d2bfa89fab8a57e61
prerequisite-patch-id: 795ab4432ffb0843e22b580374782e7e0d99b909
prerequisite-patch-id: 1499d263dc933e75366c09e045d2125ca39f7ddd
prerequisite-patch-id: f92d99bb1d35d99b063f818a19dcda999152d74c
prerequisite-patch-id: e3296f38cdba6d903e061cff2bbb3e7615e8e671
prerequisite-patch-id: bc4662b4710d302d4893f58708820fc2a0624325
prerequisite-patch-id: f8991f2e98c2661a706183fde6b35e2b8d9aedcf
prerequisite-patch-id: 44bf9ed69353586d284e5ee63d6fffa30439a698
prerequisite-patch-id: d50621bc630eeaf608bbaf260370c8dabf6326df
Best regards,
--
Bobby Eshleman <bobbyeshleman(a)meta.com>
Verify Wacom devices set INPUT_PROP_DIRECT on display devices and
INPUT_PROP_POINTER on opaque devices. Moved test_prop_pointer into
TestOpaqueTablet. Created a DirectTabletTest mixin class for
test_prop_direct that can be inherited by display tablet test classes.
Used DirectTabletTest for TestDTH2452Tablet case.
Signed-off-by: Alex Tran <alex.t.tran(a)gmail.com>
---
Changes in v2:
- Removed the tests from the BaseTest class
- Removed disabling tests for certain subclasses
- Moved test_prop_pointer under TestOpaqueTablet
- Created DirectTabletTest mixin class
- Moved test_prop_direct under TestDTH2452Tablet
.../selftests/hid/tests/test_wacom_generic.py | 30 +++++++++++--------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/hid/tests/test_wacom_generic.py b/tools/testing/selftests/hid/tests/test_wacom_generic.py
index 2d6d04f0f..9d0b0802d 100644
--- a/tools/testing/selftests/hid/tests/test_wacom_generic.py
+++ b/tools/testing/selftests/hid/tests/test_wacom_generic.py
@@ -598,18 +598,6 @@ class BaseTest:
if unit_set:
assert required[usage].contains(field)
- def test_prop_direct(self):
- """
- Todo: Verify that INPUT_PROP_DIRECT is set on display devices.
- """
- pass
-
- def test_prop_pointer(self):
- """
- Todo: Verify that INPUT_PROP_POINTER is set on opaque devices.
- """
- pass
-
class PenTabletTest(BaseTest.TestTablet):
def assertName(self, uhdev):
@@ -677,6 +665,13 @@ class TestOpaqueTablet(PenTabletTest):
uhdev.event(130, 240, pressure=0), [], auto_syn=False, strict=True
)
+ def test_prop_pointer(self):
+ """
+ Verify that INPUT_PROP_POINTER is set on opaque devices.
+ """
+ evdev = self.uhdev.get_evdev()
+ assert libevdev.INPUT_PROP_POINTER in evdev.properties
+
class TestOpaqueCTLTablet(TestOpaqueTablet):
def create_device(self):
@@ -862,7 +857,16 @@ class TestPTHX60_Pen(TestOpaqueCTLTablet):
)
-class TestDTH2452Tablet(test_multitouch.BaseTest.TestMultitouch, TouchTabletTest):
+class DirectTabletTest():
+ def test_prop_direct(self):
+ """
+ Verify that INPUT_PROP_DIRECT is set on display devices.
+ """
+ evdev = self.uhdev.get_evdev()
+ assert libevdev.INPUT_PROP_DIRECT in evdev.properties
+
+
+class TestDTH2452Tablet(test_multitouch.BaseTest.TestMultitouch, TouchTabletTest, DirectTabletTest):
ContactIds = namedtuple("ContactIds", "contact_id, tracking_id, slot_num")
def create_device(self):
--
2.51.0