Only notify Hyper-V for die events that are oops

[Joseph Salisbury]

Currently, Hyper-V may be notified of a panic for any die event.

However, this results in false panic notifications for various user space traps
that are die events.

The following commit fixes this by ignoring die events that is not an oops:

608a973bd52e ("Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops")

We would like to request this commit in all releases supported on Azure and Hyper-V.

[Joseph Salisbury (jsalisbury)]

The requested commit has now landed upstream:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/hv?h=v5.9-rc1&id=608a973bd52ef1705941b18f55e39655fcfe9cdb

[William Breathitt Gray (vilhelm-gray)]

A patch has been submitted to the Kernel Team mailing list: https://lists.ubuntu.com/archives/kernel-team/2020-August/112784.html

[William Breathitt Gray (vilhelm-gray)]

SRU Template
------------

[Impact]

Currently, Hyper-V may be notified of a panic for any die event.

However, this results in false panic notifications for various user
space traps that are die events.

The following commit fixes this by ignoring die events that is not an
oops:

608a973bd52e ("Drivers: hv: vmbus: Only notify Hyper-V for die events
that are oops")

[Test Case]

Without the fix in the Linux VM, do the following to demonstrate the
problem:

1. Create a VM in Azure.
2. Run a user space program that does a divide-by-zero. The user space
   program will terminate abnormally because of the error.
3. Monitor notifications in the Azure portal in the Resource Health
   section of the VM. There should be a report that the Linux VM has
   panicked.

With the fix, do the same steps. The panic report in Step #3 should not
happen.

[Regression Potential]

The risk of regression is low. This patch fixes the issue by ignoring
die events that aren't oops.

The upstream LKML thread mentions that DIE_PANIC may also be something
that should be reported, but it doesn't get emitted anywhere so this
might not be significantly different than DIE_OOPS.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure-4.15 - 4.15.0-1096.106

---------------
linux-azure-4.15 (4.15.0-1096.106) bionic; urgency=medium

  * bionic/linux-azure-4.15: 4.15.0-1096.106 -proposed tracker (LP: #1894683)

  * Mellanox Check For Write Combining Support (LP: #1874503)
    - RDMA/rxe: Close a race after ib_register_device
    - IB/mlx5: Align usage of QP1 create flags with rest of mlx5 defines
    - IB/mlx5: Test write combining support

  * Enable Invariant TSC Support (LP: #1875467)
    - x86/hyperv: Allow guests to enable InvariantTSC
    - x86/hyperv: Set TSC clocksource as default w/ InvariantTSC

  * Only notify Hyper-V for die events that are oops (LP: #1891222)
    - Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops

  * speed for CX4 VF showing as unknown in ethtool output (LP: #1876770)
    - net/mlx5: Expose link speed directly
    - net/mlx5: Expose port speed when possible
    - net/mlx5: Tidy up and fix reverse christmas ordring

  [ Ubuntu: 4.15.0-118.119 ]

  * bionic/linux: 4.15.0-118.119 -proposed tracker (LP: #1894697)
  * Packaging resync (LP: #1786013)
    - update dkms package versions
  * Introduce the new NVIDIA 450-server and the 450 UDA series (LP: #1887674)
    - [packaging] add signed modules for nvidia 450 and 450-server
  * cgroup refcount is bogus when cgroup_sk_alloc is disabled (LP: #1886860)
    - cgroup: add missing skcd->no_refcnt check in cgroup_sk_clone()
  * CVE-2020-12888
    - vfio/type1: Support faulting PFNMAP vmas
    - vfio-pci: Fault mmaps to enable vma tracking
    - vfio-pci: Invalidate mmaps and block MMIO access on disabled memory
  * [Hyper-V] VSS and File Copy daemons intermittently fails to start
    (LP: #1891224)
    - [Packaging] Bind hv_vss_daemon startup to hv_vss device
    - [Packaging] bind hv_fcopy_daemon startup to hv_fcopy device
  * KVM: Fix zero_page reference counter overflow when using KSM on KVM compute
    host (LP: #1837810)
    - KVM: fix overflow of zero page refcount with ksm running
  * Fix false-negative return value for rtnetlink.sh in kselftests/net
    (LP: #1890136)
    - selftests: rtnetlink: correct the final return value for the test
    - selftests: rtnetlink: make kci_test_encap() return sub-test result
  * Bionic update: upstream stable patchset 2020-08-18 (LP: #1892091)
    - USB: serial: qcserial: add EM7305 QDL product ID
    - USB: iowarrior: fix up report size handling for some devices
    - usb: xhci: define IDs for various ASMedia host controllers
    - usb: xhci: Fix ASMedia ASM1142 DMA addressing
    - Revert "ALSA: hda: call runtime_allow() for all hda controllers"
    - ALSA: seq: oss: Serialize ioctls
    - staging: android: ashmem: Fix lockdep warning for write operation
    - Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()
    - Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_evt()
    - Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_with_rssi_evt()
    - omapfb: dss: Fix max fclk divider for omap36xx
    - binder: Prevent context manager from incrementing ref 0
    - vgacon: Fix for missing check in scrollback handling
    - mtd: properly check all write i...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure - 4.15.0-1096.106~16.04.1

---------------
linux-azure (4.15.0-1096.106~16.04.1) xenial; urgency=medium

  * xenial/linux-azure: 4.15.0-1096.106~16.04.1 -proposed tracker (LP: #1894681)

  [ Ubuntu: 4.15.0-1096.106 ]

  * bionic/linux-azure-4.15: 4.15.0-1096.106 -proposed tracker (LP: #1894683)
  * Mellanox Check For Write Combining Support (LP: #1874503)
    - RDMA/rxe: Close a race after ib_register_device
    - IB/mlx5: Align usage of QP1 create flags with rest of mlx5 defines
    - IB/mlx5: Test write combining support
  * Enable Invariant TSC Support (LP: #1875467)
    - x86/hyperv: Allow guests to enable InvariantTSC
    - x86/hyperv: Set TSC clocksource as default w/ InvariantTSC
  * Only notify Hyper-V for die events that are oops (LP: #1891222)
    - Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
  * speed for CX4 VF showing as unknown in ethtool output (LP: #1876770)
    - net/mlx5: Expose link speed directly
    - net/mlx5: Expose port speed when possible
    - net/mlx5: Tidy up and fix reverse christmas ordring
  * bionic/linux: 4.15.0-118.119 -proposed tracker (LP: #1894697)
  * Packaging resync (LP: #1786013)
    - update dkms package versions
  * Introduce the new NVIDIA 450-server and the 450 UDA series (LP: #1887674)
    - [packaging] add signed modules for nvidia 450 and 450-server
  * cgroup refcount is bogus when cgroup_sk_alloc is disabled (LP: #1886860)
    - cgroup: add missing skcd->no_refcnt check in cgroup_sk_clone()
  * CVE-2020-12888
    - vfio/type1: Support faulting PFNMAP vmas
    - vfio-pci: Fault mmaps to enable vma tracking
    - vfio-pci: Invalidate mmaps and block MMIO access on disabled memory
  * [Hyper-V] VSS and File Copy daemons intermittently fails to start
    (LP: #1891224)
    - [Packaging] Bind hv_vss_daemon startup to hv_vss device
    - [Packaging] bind hv_fcopy_daemon startup to hv_fcopy device
  * KVM: Fix zero_page reference counter overflow when using KSM on KVM compute
    host (LP: #1837810)
    - KVM: fix overflow of zero page refcount with ksm running
  * Fix false-negative return value for rtnetlink.sh in kselftests/net
    (LP: #1890136)
    - selftests: rtnetlink: correct the final return value for the test
    - selftests: rtnetlink: make kci_test_encap() return sub-test result
  * Bionic update: upstream stable patchset 2020-08-18 (LP: #1892091)
    - USB: serial: qcserial: add EM7305 QDL product ID
    - USB: iowarrior: fix up report size handling for some devices
    - usb: xhci: define IDs for various ASMedia host controllers
    - usb: xhci: Fix ASMedia ASM1142 DMA addressing
    - Revert "ALSA: hda: call runtime_allow() for all hda controllers"
    - ALSA: seq: oss: Serialize ioctls
    - staging: android: ashmem: Fix lockdep warning for write operation
    - Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()
    - Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_evt()
    - Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_with_rssi_evt()
    - omapfb: dss: Fix max fclk divider for omap36xx
    - binder: Prevent context manager from incrementing ref 0
    - vgacon...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-azure - 5.4.0-1026.26

---------------
linux-azure (5.4.0-1026.26) focal; urgency=medium

  * focal/linux-azure: 5.4.0-1026.26 -proposed tracker (LP: #1894641)

  * Mellanox Check For Write Combining Support (LP: #1874503)
    - IB/mlx5: Align usage of QP1 create flags with rest of mlx5 defines
    - IB/mlx5: Test write combining support

  * Enable Invariant TSC Support (LP: #1875467)
    - x86/hyperv: Allow guests to enable InvariantTSC
    - clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC

  * Only notify Hyper-V for die events that are oops (LP: #1891222)
    - Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops

  * speed for CX4 VF showing as unknown in ethtool output (LP: #1876770)
    - net/mlx5: Expose link speed directly
    - net/mlx5: Expose port speed when possible
    - net/mlx5: Tidy up and fix reverse christmas ordring

  [ Ubuntu: 5.4.0-48.52 ]

  * focal/linux: 5.4.0-48.52 -proposed tracker (LP: #1894654)
  * mm/slub kernel oops on focal kernel 5.4.0-45 (LP: #1895109)
    - SAUCE: Revert "mm/slub: fix a memory leak in sysfs_slab_add()"
  * Packaging resync (LP: #1786013)
    - update dkms package versions
    - update dkms package versions
  * Introduce the new NVIDIA 450-server and the 450 UDA series (LP: #1887674)
    - [packaging] add signed modules for nvidia 450 and 450-server
  * [UBUNTU 20.04] zPCI attach/detach issues with PF/VF linking support
    (LP: #1892849)
    - s390/pci: fix zpci_bus_link_virtfn()
    - s390/pci: re-introduce zpci_remove_device()
    - s390/pci: fix PF/VF linking on hot plug
  * [UBUNTU 20.04] kernel: s390/cpum_cf,perf: changeDFLT_CCERROR counter name
    (LP: #1891454)
    - s390/cpum_cf, perf: change DFLT_CCERROR counter name
  * [UBUNTU 20.04] zPCI: Enabling of a reserved PCI function regression
    introduced by multi-function support (LP: #1891437)
    - s390/pci: fix enabling a reserved PCI function
  * CVE-2020-12888
    - vfio/type1: Support faulting PFNMAP vmas
    - vfio-pci: Fault mmaps to enable vma tracking
    - vfio-pci: Invalidate mmaps and block MMIO access on disabled memory
  * [Hyper-V] VSS and File Copy daemons intermittently fails to start
    (LP: #1891224)
    - [Packaging] Bind hv_vss_daemon startup to hv_vss device
    - [Packaging] bind hv_fcopy_daemon startup to hv_fcopy device
  * alsa/hdmi: support nvidia mst hdmi/dp audio (LP: #1867704)
    - ALSA: hda - Rename snd_hda_pin_sense to snd_hda_jack_pin_sense
    - ALSA: hda - Add DP-MST jack support
    - ALSA: hda - Add DP-MST support for non-acomp codecs
    - ALSA: hda - Add DP-MST support for NVIDIA codecs
    - ALSA: hda: hdmi - fix regression in connect list handling
    - ALSA: hda: hdmi - fix kernel oops caused by invalid PCM idx
    - ALSA: hda: hdmi - preserve non-MST PCM routing for Intel platforms
    - ALSA: hda: hdmi - Keep old slot assignment behavior for Intel platforms
    - ALSA: hda - Fix DP-MST support for NVIDIA codecs
  * Focal update: v5.4.60 upstream stable release (LP: #1892899)
    - smb3: warn on confusing error scenario with sec=krb5
    - genirq/affinity: Make affinity setting if activated opt-in
    - ...