[GLK/CLX] Enhanced IBRS

[quanxian]

Description:

[Impact]

Future Intel CPU's like Cascade Lake and GLK+ support Enhanced IBRS. Enhanced IBRS is a H/W mitigation technique for Spectre V2 bug. So, it's important for us to make sure that all the OSV's are using this feature.

The patch that enables kernel support for this feature has been taken by Thomas and it's in TIP tree. So, please back port it to all the OSV's. Please find the patch here: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=x86/pti&id=706d51681d636a0c4a5ef53395ec3b803e45ed4d

[Test Case]

For processors that don't support Enhanced IBRS, the test is to ensure that /sys/devices/system/cpu/vulnerabilities/spectre_v2 doesn't change state after applying the patches. This will typically be the string when running on Intel processors that don't support Enhanced IBRS:

  "Mitigation: Full generic retpoline, IBPB, IBRS_FW"

New Intel processors that do support Enhanced IBRS will display "Enhanced IBRS" in place of "Full generic retpoline"

[Regression Potential]

Pretty low. The patches are fairly simple and they should only affect new processors. The main concern is around the possibility of regressing IBRS support on processors that don't support Enhanced IBRS

Target Kernel:TBD
Target Release: 19.04

[quanxian (quanxian-wang)]

since 18.10 will use 4.17. this feature need backporting

git describe 706d51681d636a0c4a5ef53395ec3b803e45ed4d
v4.18-rc4-220-g706d51681d63

[[e-mail] (pragyan)]

Brad - Could you update the status of this feature. Has this been pulled in to Ubuntu 18.10 and previous Ubuntu releases that will provide support to CLX and beyond CPU?
Thanks

[Tyler Hicks (tyhicks)]

Hello - We've not backported this patch yet. I'll take assignment of the bug and begin work on it shortly.

Note that comment #1 is misleading for two reasons:

 1) 18.10 is actually using 4.18
 2) The git describe command did not include the --contains option so the upstream kernel version is incorrect

The commit landed in v4.19 so it is not included in Ubuntu 18.10's kernel:

$ git describe --contains 706d51681d636a0c4a5ef53395ec3b803e45ed4
v4.19-rc1~193^2~6

@pragyan can we make this bug report public? I need a public bug report to take the patch through the kernel SRU process.

[[e-mail] (pragyan)]

Yes this can be made public. Thanks

[[e-mail] (pragyan)]

Tyler
1. Will this make Ubuntu 18.10 or will this be part of SRU release?
2. Will this be back ported Ubuntu 18.04.1 LTS and Ubuntu 18.04 LTS release?

Thanks

[Tyler Hicks (tyhicks)]

On 2018-10-12 23:24:53, <email address hidden> wrote:
> 1. Will this make Ubuntu 18.10 or will this be part of SRU release?

No, it will be part of an SRU release.

> 2. Will this be back ported Ubuntu 18.04.1 LTS and Ubuntu 18.04 LTS release?

Yes, it will be.

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

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1786139

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Tyler Hicks (tyhicks)]

I've marked the Ubuntu 14.04 LTS (Trusty) task as Won't Fix. The backport is not nearly as simple as the other releases and I don't feel like the risk of regression is worth it on that release considering that this is a new hardware enablement type of a feature and Ubuntu 14.04 LTS only has 6 months of official support left. Users that are stuck on Ubuntu 14.04 LTS will be able to use the enablement kernel to get this feature:

  https://wiki.ubuntu.com/Kernel/LTSEnablementStack#Ubuntu_14.04_LTS_-_Trusty_Tahr

[Brad Figg (brad-figg)]

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!

[Brad Figg (brad-figg)]

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!

[Brad Figg (brad-figg)]

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-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

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!

[Tyler Hicks (tyhicks)]

I've verified the [Test Case] for older processors that do not support Enhanced IBRS. I've asked Intel if they'd be able to verify the this fix on the latest processors that support Enhanced IBRS but I don't feel like that should be a blocker.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.18.0-12.13

---------------
linux (4.18.0-12.13) cosmic; urgency=medium

  * linux: 4.18.0-12.13 -proposed tracker (LP: #1802743)

  * [FEAT] Guest-dedicated Crypto Adapters (LP: #1787405)
    - s390/zcrypt: Add ZAPQ inline function.
    - s390/zcrypt: Review inline assembler constraints.
    - s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.
    - s390/zcrypt: fix ap_instructions_available() returncodes
    - KVM: s390: vsie: simulate VCPU SIE entry/exit
    - KVM: s390: introduce and use KVM_REQ_VSIE_RESTART
    - KVM: s390: refactor crypto initialization
    - s390: vfio-ap: base implementation of VFIO AP device driver
    - s390: vfio-ap: register matrix device with VFIO mdev framework
    - s390: vfio-ap: sysfs interfaces to configure adapters
    - s390: vfio-ap: sysfs interfaces to configure domains
    - s390: vfio-ap: sysfs interfaces to configure control domains
    - s390: vfio-ap: sysfs interface to view matrix mdev matrix
    - KVM: s390: interface to clear CRYCB masks
    - s390: vfio-ap: implement mediated device open callback
    - s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl
    - s390: vfio-ap: zeroize the AP queues
    - s390: vfio-ap: implement VFIO_DEVICE_RESET ioctl
    - KVM: s390: Clear Crypto Control Block when using vSIE
    - KVM: s390: vsie: Do the CRYCB validation first
    - KVM: s390: vsie: Make use of CRYCB FORMAT2 clear
    - KVM: s390: vsie: Allow CRYCB FORMAT-2
    - KVM: s390: vsie: allow CRYCB FORMAT-1
    - KVM: s390: vsie: allow CRYCB FORMAT-0
    - KVM: s390: vsie: allow guest FORMAT-0 CRYCB on host FORMAT-1
    - KVM: s390: vsie: allow guest FORMAT-1 CRYCB on host FORMAT-2
    - KVM: s390: vsie: allow guest FORMAT-0 CRYCB on host FORMAT-2
    - KVM: s390: device attrs to enable/disable AP interpretation
    - KVM: s390: CPU model support for AP virtualization
    - s390: doc: detailed specifications for AP virtualization
    - KVM: s390: fix locking for crypto setting error path
    - KVM: s390: Tracing APCB changes
    - s390: vfio-ap: setup APCB mask using KVM dedicated function
    - [Config:] Enable CONFIG_S390_AP_IOMMU and set CONFIG_VFIO_AP to module.

  * Bypass of mount visibility through userns + mount propagation (LP: #1789161)
    - mount: Retest MNT_LOCKED in do_umount
    - mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts

  * CVE-2018-18955: nested user namespaces with more than five extents
    incorrectly grant privileges over inode (LP: #1801924) // CVE-2018-18955
    - userns: also map extents in the reverse map to kernel IDs

  * kdump fail due to an IRQ storm (LP: #1797990)
    - SAUCE: x86/PCI: Export find_cap() to be used in early PCI code
    - SAUCE: x86/quirks: Add parameter to clear MSIs early on boot
    - SAUCE: x86/quirks: Scan all busses for early PCI quirks

  * crash in ENA driver on removing an interface (LP: #1802341)
    - SAUCE: net: ena: fix crash during ena_remove()

  * Ubuntu 18.04.1 - [s390x] Kernel panic while stressing network bonding
    (LP: #1797367)
    - s390/qeth: reduce hard-coded access to ccw channels
    - s390/qeth: sanitize strings in debug messages

  * Add checksum offload and T...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-42.45

---------------
linux (4.15.0-42.45) bionic; urgency=medium

  * linux: 4.15.0-42.45 -proposed tracker (LP: #1803592)

  * [FEAT] Guest-dedicated Crypto Adapters (LP: #1787405)
    - KVM: s390: reset crypto attributes for all vcpus
    - KVM: s390: vsie: simulate VCPU SIE entry/exit
    - KVM: s390: introduce and use KVM_REQ_VSIE_RESTART
    - KVM: s390: refactor crypto initialization
    - s390: vfio-ap: base implementation of VFIO AP device driver
    - s390: vfio-ap: register matrix device with VFIO mdev framework
    - s390: vfio-ap: sysfs interfaces to configure adapters
    - s390: vfio-ap: sysfs interfaces to configure domains
    - s390: vfio-ap: sysfs interfaces to configure control domains
    - s390: vfio-ap: sysfs interface to view matrix mdev matrix
    - KVM: s390: interface to clear CRYCB masks
    - s390: vfio-ap: implement mediated device open callback
    - s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl
    - s390: vfio-ap: zeroize the AP queues
    - s390: vfio-ap: implement VFIO_DEVICE_RESET ioctl
    - KVM: s390: Clear Crypto Control Block when using vSIE
    - KVM: s390: vsie: Do the CRYCB validation first
    - KVM: s390: vsie: Make use of CRYCB FORMAT2 clear
    - KVM: s390: vsie: Allow CRYCB FORMAT-2
    - KVM: s390: vsie: allow CRYCB FORMAT-1
    - KVM: s390: vsie: allow CRYCB FORMAT-0
    - KVM: s390: vsie: allow guest FORMAT-0 CRYCB on host FORMAT-1
    - KVM: s390: vsie: allow guest FORMAT-1 CRYCB on host FORMAT-2
    - KVM: s390: vsie: allow guest FORMAT-0 CRYCB on host FORMAT-2
    - KVM: s390: device attrs to enable/disable AP interpretation
    - KVM: s390: CPU model support for AP virtualization
    - s390: doc: detailed specifications for AP virtualization
    - KVM: s390: fix locking for crypto setting error path
    - KVM: s390: Tracing APCB changes
    - s390: vfio-ap: setup APCB mask using KVM dedicated function
    - s390/zcrypt: Add ZAPQ inline function.
    - s390/zcrypt: Review inline assembler constraints.
    - s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.
    - s390/zcrypt: fix ap_instructions_available() returncodes
    - s390/zcrypt: remove VLA usage from the AP bus
    - s390/zcrypt: Remove deprecated ioctls.
    - s390/zcrypt: Remove deprecated zcrypt proc interface.
    - s390/zcrypt: Support up to 256 crypto adapters.
    - [Config:] Enable CONFIG_S390_AP_IOMMU and set CONFIG_VFIO_AP to module.

  * Bypass of mount visibility through userns + mount propagation (LP: #1789161)
    - mount: Retest MNT_LOCKED in do_umount
    - mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts

  * CVE-2018-18955: nested user namespaces with more than five extents
    incorrectly grant privileges over inode (LP: #1801924) // CVE-2018-18955
    - userns: also map extents in the reverse map to kernel IDs

  * kdump fail due to an IRQ storm (LP: #1797990)
    - SAUCE: x86/PCI: Export find_cap() to be used in early PCI code
    - SAUCE: x86/quirks: Add parameter to clear MSIs early on boot
    - SAUCE: x86/quirks: Scan all busses for early PCI quirks

 -- Thadeu Lima de Souza Cascardo <email address hidden> Thu, 15 Nov 2018 17:01:46 ...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-140.166

---------------
linux (4.4.0-140.166) xenial; urgency=medium

  * linux: 4.4.0-140.166 -proposed tracker (LP: #1802776)

  * Bypass of mount visibility through userns + mount propagation (LP: #1789161)
    - mount: Retest MNT_LOCKED in do_umount
    - mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts

  * kdump fail due to an IRQ storm (LP: #1797990)
    - SAUCE: x86/PCI: Export find_cap() to be used in early PCI code
    - SAUCE: x86/quirks: Add parameter to clear MSIs early on boot
    - SAUCE: x86/quirks: Scan all busses for early PCI quirks

  * crash in ENA driver on removing an interface (LP: #1802341)
    - SAUCE: net: ena: fix crash during ena_remove()

  * xenial guest on arm64 drops to busybox under openstack bionic-rocky
    (LP: #1797092)
    - [Config] CONFIG_PCI_ECAM=y
    - PCI: Provide common functions for ECAM mapping
    - PCI: generic, thunder: Use generic ECAM API
    - PCI, of: Move PCI I/O space management to PCI core code
    - PCI: Move ecam.h to linux/include/pci-ecam.h
    - PCI: Add parent device field to ECAM struct pci_config_window
    - PCI: Add pci_unmap_iospace() to unmap I/O resources
    - PCI/ACPI: Support I/O resources when parsing host bridge resources
    - [Config] CONFIG_ACPI_MCFG=y
    - PCI/ACPI: Add generic MCFG table handling
    - PCI: Refactor pci_bus_assign_domain_nr() for CONFIG_PCI_DOMAINS_GENERIC
    - PCI: Factor DT-specific pci_bus_find_domain_nr() code out
    - ARM64: PCI: Add acpi_pci_bus_find_domain_nr()
    - ARM64: PCI: ACPI support for legacy IRQs parsing and consolidation with DT
      code
    - ARM64: PCI: Support ACPI-based PCI host controller

  * [GLK/CLX] Enhanced IBRS (LP: #1786139)
    - x86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation
    - x86/speculation: Support Enhanced IBRS on future CPUs

  * Update ENA driver to version 2.0.1K (LP: #1798182)
    - net: ena: remove ndo_poll_controller
    - net: ena: fix warning in rmmod caused by double iounmap
    - net: ena: fix rare bug when failed restart/resume is followed by driver
      removal
    - net: ena: fix NULL dereference due to untimely napi initialization
    - net: ena: fix auto casting to boolean
    - net: ena: minor performance improvement
    - net: ena: complete host info to match latest ENA spec
    - net: ena: introduce Low Latency Queues data structures according to ENA spec
    - net: ena: add functions for handling Low Latency Queues in ena_com
    - net: ena: add functions for handling Low Latency Queues in ena_netdev
    - net: ena: use CSUM_CHECKED device indication to report skb's checksum status
    - net: ena: explicit casting and initialization, and clearer error handling
    - net: ena: limit refill Rx threshold to 256 to avoid latency issues
    - net: ena: change rx copybreak default to reduce kernel memory pressure
    - net: ena: remove redundant parameter in ena_com_admin_init()
    - net: ena: update driver version to 2.0.1
    - net: ena: fix indentations in ena_defs for better readability
    - net: ena: Fix Kconfig dependency on X86
    - net: ena: enable Low Latency Queues
    - net: ena: fix compilat...

[Tyler Hicks (tyhicks)]

Disco is based on a 5.0 upstream kernel so it has enhanced IBRS support.