Provide mode where all vCPUs on a core must be the same VM

I built a test kernel with the requested commit.
 The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792957

Can you test this kernel and see if it resolves this bug?

Note about installing test kernels:
• If the test kernel is prior to 4.15(Bionic) you need to install the linux-image and linux-image-extra .deb packages.
• If the test kernel is 4.15(Bionic) or newer, you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

Thanks in advance!

Hi Joseph,

> I built a test kernel with the requested commit.
> The test kernel can be downloaded from:
> http://kernel.ubuntu.com/~jsalisbury/lp1792957
>
> Can you test this kernel and see if it resolves this bug?

I tested this kernel in the following scenarios:

 - Booted the host on a P9 machine and started an 18.04 guest using the default parameters.
 - Removed the kvm_hv module and reinstalled it using the 'one_vm_per_core' parameter, shut down the 18.04 guest and restarted it.

➜ ~ sudo virsh destroy breno-1804
➜ ~ sudo rmmod kvm_hv
➜ ~ sudo modprobe kvm_hv one_vm_per_core=1
➜ ~ sudo virsh start --console breno-1804

On both guests I ran sysbench, as:

breno@ubuntu:~$ sysbench --threads=16 cpu run
sysbench 1.0.11 (using system LuaJIT 2.1.0-beta3)

Running the test with following options:

breno@ubuntu:~$ sysbench --threads=16 cpu run
   Number of threads: 16
   Initializing random number generator from current time
   Prime numbers limit: 10000
   Initializing worker threads...
   Threads started!

   CPU speed:
       events per second: 33648.49
   .....

Everything worked fine. I think this patch is good to get accepted.

SRU request submitted:
https://lists.ubuntu.com/archives/kernel-team/2018-October/095982.html

hi Joseph,

I understand this patch will make the next SRU, correct?

Hi Breno,

That is correct.

This bug is awaiting verification that the 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!

This bug is awaiting verification that the 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-cosmic' to 'verification-done-cosmic'. If the problem still exists, change the tag 'verification-needed-cosmic' to 'verification-failed-cosmic'.

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!

Hello IBM,

Could you please verify if the Bionic and Cosmic kernels currently in -proposed resolves the issue?

Thank you.

------- Comment From <email address hidden> 2018-11-12 14:53 EDT-------
Sorry for the delay.

I tested it and it is OK;

# uname -a
Linux ltc-wspoon3 4.15.0-39-generic #42-Ubuntu SMP Tue Oct 23 15:41:45 UTC 2018 ppc64le ppc64le ppc64le GNU/Linux

Thanks Breno. Changing bionic verification tag to done.
Is the cosmic -proposed kernel also ok?

This bug was fixed in the package linux - 4.15.0-39.42

---------------
linux (4.15.0-39.42) bionic; urgency=medium

  * linux: 4.15.0-39.42 -proposed tracker (LP: #1799411)

  * Linux: insufficient shootdown for paging-structure caches (LP: #1798897)
    - mm: move tlb_table_flush to tlb_flush_mmu_free
    - mm/tlb: Remove tlb_remove_table() non-concurrent condition
    - mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE
    - [Config] CONFIG_HAVE_RCU_TABLE_INVALIDATE=y

  * Ubuntu18.04: GPU total memory is reduced (LP: #1792102)
    - Revert "powerpc/powernv: Increase memory block size to 1GB on radix"

  * arm64: snapdragon: reduce boot noise (LP: #1797154)
    - [Config] arm64: snapdragon: DRM_MSM=m
    - [Config] arm64: snapdragon: SND*=m
    - [Config] arm64: snapdragon: disable ARM_SDE_INTERFACE
    - [Config] arm64: snapdragon: disable DRM_I2C_ADV7511_CEC
    - [Config] arm64: snapdragon: disable VIDEO_ADV7511, VIDEO_COBALT

  * [Bionic] CPPC bug fixes (LP: #1796949)
    - ACPI / CPPC: Update all pr_(debug/err) messages to log the susbspace id
    - cpufreq: CPPC: Don't set transition_latency
    - ACPI / CPPC: Fix invalid PCC channel status errors

  * regression in 'ip --family bridge neigh' since linux v4.12 (LP: #1796748)
    - rtnetlink: fix rtnl_fdb_dump() for ndmsg header

  * screen displays abnormally on the lenovo M715 with the AMD GPU (Radeon Vega
    8 Mobile, rev ca, 1002:15dd) (LP: #1796786)
    - drm/amd/display: Fix takover from VGA mode
    - drm/amd/display: early return if not in vga mode in disable_vga
    - drm/amd/display: Refine disable VGA

  * arm64: snapdragon: WARNING: CPU: 0 PID: 1 arch/arm64/kernel/setup.c:271
    reserve_memblock_reserved_regions (LP: #1797139)
    - SAUCE: arm64: Fix /proc/iomem for reserved but not memory regions

  * The front MIC can't work on the Lenovo M715 (LP: #1797292)
    - ALSA: hda/realtek - Fix the problem of the front MIC on the Lenovo M715

  * Keyboard backlight sysfs sometimes is missing on Dell laptops (LP: #1797304)
    - platform/x86: dell-smbios: Correct some style warnings
    - platform/x86: dell-smbios: Rename dell-smbios source to dell-smbios-base
    - platform/x86: dell-smbios: Link all dell-smbios-* modules together
    - [Config] CONFIG_DELL_SMBIOS_SMM=y, CONFIG_DELL_SMBIOS_WMI=y

  * rpi3b+: ethernet not working (LP: #1797406)
    - lan78xx: Don't reset the interface on open

  * 87cdf3148b11 was never backported to 4.15 (LP: #1795653)
    - xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto

  * [Ubuntu18.04][Power9][DD2.2]package installation segfaults inside debian
    chroot env in P9 KVM guest with HTM enabled (kvm) (LP: #1792501)
    - KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds

  * Provide mode where all vCPUs on a core must be the same VM (LP: #1792957)
    - KVM: PPC: Book3S HV: Provide mode where all vCPUs on a core must be the same
      VM

  * fscache: bad refcounting in fscache_op_complete leads to OOPS (LP: #1797314)
    - SAUCE: fscache: Fix race in decrementing refcount of op->npages

  * CVE-2018-9363
    - Bluetooth: hidp: buffer overflow in hidp_process_report

  * CVE-20...

This bug was fixed in the package linux - 4.18.0-11.12

---------------
linux (4.18.0-11.12) cosmic; urgency=medium

  * linux: 4.18.0-11.12 -proposed tracker (LP: #1799445)

  * arm64: snapdragon: WARNING: CPU: 0 PID: 1 arch/arm64/kernel/setup.c:271
    reserve_memblock_reserved_regions (LP: #1797139)
    - SAUCE: arm64: Fix /proc/iomem for reserved but not memory regions

  * arm64: snapdragon: WARNING: CPU: 0 PID: 1 at drivers/irqchip/irq-gic.c:1016
    gic_irq_domain_translate (LP: #1797143)
    - SAUCE: arm64: dts: msm8916: camms: fix gic_irq_domain_translate warnings

  * The front MIC can't work on the Lenovo M715 (LP: #1797292)
    - ALSA: hda/realtek - Fix the problem of the front MIC on the Lenovo M715

  * Provide mode where all vCPUs on a core must be the same VM (LP: #1792957)
    - KVM: PPC: Book3S HV: Provide mode where all vCPUs on a core must be the same
      VM

  * fscache: bad refcounting in fscache_op_complete leads to OOPS (LP: #1797314)
    - SAUCE: fscache: Fix race in decrementing refcount of op->npages

  * hns3: autoneg settings get lost on down/up (LP: #1797654)
    - net: hns3: Fix for information of phydev lost problem when down/up

  * not able to unwind the stack from within __kernel_clock_gettime in the Linux
    vDSO (LP: #1797963)
    - powerpc/vdso: Correct call frame information

  * Signal 7 error when running GPFS tracing in cluster (LP: #1792195)
    - powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.
    - powerpc/mm/radix: Only need the Nest MMU workaround for R -> RW transition

  * Support Edge Gateway's WIFI LED (LP: #1798330)
    - SAUCE: mwifiex: Switch WiFi LED state according to the device status

  * Support Edge Gateway's Bluetooth LED (LP: #1798332)
    - SAUCE: Bluetooth: Support for LED on Edge Gateways

  * kvm doesn't work on 36 physical bits systems (LP: #1798427)
    - KVM: x86: fix L1TF's MMIO GFN calculation

  * CVE-2018-15471
    - xen-netback: fix input validation in xenvif_set_hash_mapping()

  * regression in 'ip --family bridge neigh' since linux v4.12 (LP: #1796748)
    - rtnetlink: fix rtnl_fdb_dump() for ndmsg header

 -- Stefan Bader <email address hidden> Tue, 23 Oct 2018 18:59:15 +0200

------- Comment From <email address hidden> 2018-11-21 10:56 EDT-------
(In reply to comment #17)
> Thanks Breno. Changing bionic verification tag to done.
> Is the cosmic -proposed kernel also ok?

Yes!