[UBUNTU 20.04] Fix SIGP processing on KVM/s390

[bugproxy]

SRU Justification:
==================

[Impact]

* The SIGP processing on KVM/s390x is incorrect and not fully conform to
  the 'Principles of Operations', the IBM Z architecture definition
  and documentation.

* KVM: SIGP RESTART is reporting a CPU state 'stopped' after SIGP RESTART
  was issued, while it should report a 'busy' condition until the CPU is
  really started.

* The fix for this consists of three patches:
  812de04661c4 "KVM: s390: Clarify SIGP orders versus STOP/RESTART"
  435d17955519 "KVM: s390: Add a routine for setting userspace CPU state"
  4563bcad46bf "KVM: s390: Simplify SIGP Set Arch handling"
  whereas 812de04661c4 already landed via upstream stable,
  hence only two are left and need to be cherry-picked:

[Fix]

* 67cf68b6a5ccac8bc7dfef0a220b59af4c83fd2c 67cf68b6a5cc "KVM: s390: Add a routine for setting userspace CPU state"

* 8eeba194a32e0f50329354a696baaa2e3d9accc5 8eeba194a32e "KVM: s390: Simplify SIGP Set Arch handling"

[Test Case]

* Install an LPAR on IBM Z (z13+) or LinuxONE (Emperor / Rockhopper)
  with Ubuntu Server 20.04 using kernel standard kernel 5.4.

* Setup this LPAR as QEMU/KVM host and a focal VM as guest.

* The test itself is the following unit test:
  https://<email address hidden>/

* The test and verification will be done by the IBM Z team.

[Where problems could occur]

* A broken patch could harm KVM ioctl on s390x or the (virtual) CPU
  state control in general.

* The SIGP handing (on s390x) can become broken, which could lead to
  incorrect (virtual) CPU states.

* In worst case KVM can become broken on s390x entirely.

* The modified code is all s390x specific QEMU/KVM code,
  no common code is touched.

[Other]

* The two remaining patches are upstream since 5.16,
  the first one already landed in 5.4 via upstream stable bug LP#1959701
  and in 5.13 via upstream stable bug LP#1960861.

* The patches already landed in jammy (master-next) based on LP#1959735,
  hence only SRU to impish and focal is needed.

* This patches got discussed here:
  https://<email address hidden>/

* This not only fixes the SIGP processing, but is also important in terms of
  long term maintainability.

__________

Description:
   KVM: SIGP RESTART is reporting a CPU state 'stopped' after SIGP RESTART was issued, while it should report a 'busy' condition until the CPU is really started.

 The patches to fix this have already been picked for jammy/master-next:

812de04661c4 "KVM: s390: Clarify SIGP orders versus STOP/RESTART"
435d17955519 "KVM: s390: Add a routine for setting userspace CPU state"
4563bcad46bf "KVM: s390: Simplify SIGP Set Arch handling"

 For Ubuntu 20.04 the focal/master-next already contains:
d74b0d2d38d3 KVM: s390: Clarify SIGP orders versus STOP/RESTART

 so we additionally need the following two upstream commits in focal
67cf68b6a5cc KVM: s390: Add a routine for setting userspace CPU state
8eeba194a32e KVM: s390: Simplify SIGP Set Arch handling

[bugproxy (bugproxy)]

This was adressed in jammy by LP#1959735, hence updating the jammy entry to Fix Released.

[Frank Heimes (fheimes)]

To avoid any regressions after upgrades, it's needed that Impish/21.10 is patched, too.
(SIGP fix is already addressed for jammy in LP#/1959735)

I just check the impish master-next tree and the situation is the same like on focal.
Just the following two need to be added to focal and impish:
67cf68b6a5cc KVM: s390: Add a routine for setting userspace CPU state
8eeba194a32e KVM: s390: Simplify SIGP Set Arch handling

[Frank Heimes (fheimes)]

Kernel test builds:
linux - 5.13.0-32.35~lp1962578
linux - 5.4.0-102.115~lp1962578
that incl. the commits mentioned above are available here:
https://launchpad.net/~fheimes/+archive/ubuntu/lp1962578

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2022-03-03 16:21 EDT-------
A draft of the kvm-unit-test patches for these changes are now posted upstream:

https://<email address hidden>/

There are a couple of additional cleanups in the series, but the key points are:
- (Patch 1) The SIGP SENSE used to determine if a CPU is operating/stopped now loops if it returns a CC2 (now possible with the kernel changes here)
- (Patch 4 and 5) The test of the SIGP STOP/RESTART opcodes don't do any additional looping other than that CC2 loop for a SIGP SENSE

[Frank Heimes (fheimes)]

Many thx, Eric!

[Frank Heimes (fheimes)]

SRU request submitted to the Ubuntu kernel team mailing list for impish and focal:
https://lists.ubuntu.com/archives/kernel-team/2022-March/thread.html#128464
Changing status to 'In Progress' for impish and focal.

[bugproxy (bugproxy)]

https://lists.ubuntu.com/archives/kernel-team/2022-March/thread.html#128449

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux/5.13.0-38.43 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-impish' to 'verification-done-impish'. If the problem still exists, change the tag 'verification-needed-impish' to 'verification-failed-impish'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux/5.4.0-106.120 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2022-03-23 11:42 EDT-------
Verified with the assistance of kvm-unit-tests patches described here:
https://<email address hidden>/

...and further examination of the s390dbf/kvm-<pid> contents for a running guest. Rolled back the kernel version on each release to ensure I had a "bad" state, as well as the version in -proposed. Everything behaves as I expected. THANK YOU!

Tested Focal:
5.4.0-100.113 (FAILS)
5.4.0-106.120 (WORKS)

Tested Impish:
5.13.0-30.33 (FAILS)
5.13.0-38.43 (WORKS)

[Frank Heimes (fheimes)]

Thank you Eric for the verifications!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-hwe-5.4/5.4.0-107.121~18.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Frank Heimes (fheimes)]

This bug was opened for focal and impish, bionic was not really requested and is not marked as affected, so I'm setting the verification-done-bionic tag to unblock further SRU processing.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.13.0-40.45

---------------
linux (5.13.0-40.45) impish; urgency=medium

  * impish/linux: 5.13.0-40.45 -proposed tracker (LP: #1966701)

  * CVE-2022-1016
    - netfilter: nf_tables: initialize registers in nft_do_chain()

  * CVE-2022-1015
    - netfilter: nf_tables: validate registers coming from userspace.

  * audit: improve audit queue handling when "audit=1" on cmdline
    (LP: #1965723) // Impish update: upstream stable patchset 2022-03-22
    (LP: #1966021)
    - audit: improve audit queue handling when "audit=1" on cmdline

  * PS/2 Keyboard wakeup from s2idle not functioning on AMD Yellow Carp platform
    (LP: #1961739)
    - PM: s2idle: ACPI: Fix wakeup interrupts handling

  * Low RX performance for 40G Solarflare NICs (LP: #1964512)
    - SAUCE: sfc: The size of the RX recycle ring should be more flexible

  * [UBUNTU 20.04] Fix SIGP processing on KVM/s390 (LP: #1962578)
    - KVM: s390: Simplify SIGP Set Arch handling
    - KVM: s390: Add a routine for setting userspace CPU state

  * Move virtual graphics drivers from linux-modules-extra to linux-modules
    (LP: #1960633)
    - [Packaging] Move VM DRM drivers into modules

  * Impish update: upstream stable patchset 2022-03-09 (LP: #1964422)
    - bnx2x: Utilize firmware 7.13.21.0
    - bnx2x: Invalidate fastpath HSI version for VFs
    - rcu: Tighten rcu_advance_cbs_nowake() checks
    - select: Fix indefinitely sleeping task in poll_schedule_timeout()
    - drm/amdgpu: Use correct VIEWPORT_DIMENSION for DCN2
    - arm64/bpf: Remove 128MB limit for BPF JIT programs
    - Bluetooth: refactor malicious adv data check
    - net: sfp: ignore disabled SFP node
    - net: stmmac: skip only stmmac_ptp_register when resume from suspend
    - s390/hypfs: include z/VM guests with access control group set
    - bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack()
    - scsi: zfcp: Fix failed recovery on gone remote port with non-NPIV FCP
      devices
    - udf: Restore i_lenAlloc when inode expansion fails
    - udf: Fix NULL ptr deref when converting from inline format
    - efi: runtime: avoid EFIv2 runtime services on Apple x86 machines
    - PM: wakeup: simplify the output logic of pm_show_wakelocks()
    - tracing/histogram: Fix a potential memory leak for kstrdup()
    - tracing: Don't inc err_log entry count if entry allocation fails
    - ceph: properly put ceph_string reference after async create attempt
    - ceph: set pool_ns in new inode layout for async creates
    - fsnotify: fix fsnotify hooks in pseudo filesystems
    - Revert "KVM: SVM: avoid infinite loop on NPF from bad address"
    - perf/x86/intel/uncore: Fix CAS_COUNT_WRITE issue for ICX
    - drm/etnaviv: relax submit size limits
    - KVM: x86: Update vCPU's runtime CPUID on write to MSR_IA32_XSS
    - netfilter: nft_payload: do not update layer 4 checksum when mangling
      fragments
    - serial: 8250: of: Fix mapped region size when using reg-offset property
    - serial: stm32: fix software flow control transfer
    - tty: n_gsm: fix SW flow control encoding/handling
    - tty: Add support for Brainboxes UC cards.
    - usb-storage: Add unusual-devs...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 5.4.0-109.123

---------------
linux (5.4.0-109.123) focal; urgency=medium

  * focal/linux: 5.4.0-109.123 -proposed tracker (LP: #1968290)

  * USB devices not detected during boot on USB 3.0 hubs (LP: #1968210)
    - SAUCE: Revert "Revert "xhci: Set HCD flag to defer primary roothub
      registration""
    - SAUCE: Revert "Revert "usb: core: hcd: Add support for deferring roothub
      registration""

linux (5.4.0-108.122) focal; urgency=medium

  * focal/linux: 5.4.0-108.122 -proposed tracker (LP: #1966740)

  * Packaging resync (LP: #1786013)
    - [Packaging] resync dkms-build{,--nvidia-N} from LRMv5
    - debian/dkms-versions -- update from kernel-versions (main/2022.03.21)

  * Low RX performance for 40G Solarflare NICs (LP: #1964512)
    - SAUCE: sfc: The size of the RX recycle ring should be more flexible

  * [UBUNTU 20.04] KVM: Enable storage key checking for intercepted instruction
    (LP: #1962831)
    - selftests: kvm: add _vm_ioctl
    - selftests: kvm: Introduce the TEST_FAIL macro
    - KVM: selftests: Add GUEST_ASSERT variants to pass values to host
    - KVM: s390: gaccess: Refactor gpa and length calculation
    - KVM: s390: gaccess: Refactor access address range check
    - KVM: s390: gaccess: Cleanup access to guest pages
    - s390/uaccess: introduce bit field for OAC specifier
    - s390/uaccess: fix compile error
    - s390/uaccess: Add copy_from/to_user_key functions
    - KVM: s390: Honor storage keys when accessing guest memory
    - KVM: s390: handle_tprot: Honor storage keys
    - KVM: s390: selftests: Test TEST PROTECTION emulation
    - KVM: s390: Add optional storage key checking to MEMOP IOCTL
    - KVM: s390: Add vm IOCTL for key checked guest absolute memory access
    - KVM: s390: Rename existing vcpu memop functions
    - KVM: s390: Add capability for storage key extension of MEM_OP IOCTL
    - KVM: s390: Update api documentation for memop ioctl
    - KVM: s390: Clarify key argument for MEM_OP in api docs
    - KVM: s390: Add missing vm MEM_OP size check

  * 【sec-0911】 fail to reset sec module (LP: #1943301)
    - crypto: hisilicon/sec2 - Add workqueue for SEC driver.
    - crypto: hisilicon/sec2 - update SEC initialization and reset

  * Lots of hisi_qm zombie task slow down system after stress test
    (LP: #1932117)
    - crypto: hisilicon - Use one workqueue per qm instead of per qp

  * Lots of hisi_qm zombie task slow down system after stress test
    (LP: #1932117) // 【sec-0911】 fail to reset sec module (LP: #1943301)
    - crypto: hisilicon - Unify hardware error init/uninit into QM

  * [UBUNTU 20.04] Fix SIGP processing on KVM/s390 (LP: #1962578)
    - KVM: s390: Simplify SIGP Set Arch handling
    - KVM: s390: Add a routine for setting userspace CPU state

  * Move virtual graphics drivers from linux-modules-extra to linux-modules
    (LP: #1960633)
    - [Packaging] Move VM DRM drivers into modules

  * Focal update: v5.4.178 upstream stable release (LP: #1964634)
    - audit: improve audit queue handling when "audit=1" on cmdline
    - ASoC: ops: Reject out of bounds values in snd_soc_put_volsw()
    - ASoC: ops: Reject out of bounds values in snd_...

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2022-05-06 12:21 EDT-------
Fix released to -updates with last SRU cycle on April 18, hence closing the bug.

Changing Status to: -> CLOSED.