[SRU][G/aws][PULL] aws: update Xen hibernation patch set

[Andrea Righi]

BugLink: https://bugs.launchpad.net/bugs/1913410
BugLink: https://bugs.launchpad.net/bugs/1906850

[Impact]

Amazon maintains a custom kernel patch set to properly support
hibernation in Xen.

This patch set is available in the amazonlinux kernel git repository:
https://github.com/amazonlinux/linux.git

It is important to periodically re-sync our version of this patch set
with the new versions that are pushed by Amazon and make sure we include
all the required patches and drop the old ones.

This pull request is a revert of the old xen/hibernation patch set +
applying the new patch set.

Many of these patches required a small backporting activity, mostly due
to context adjustments (no functional changes).

[Test case]

A test kernel with this new patch set applied has been extensively
tested in the AWS cloud both by our testing scripts (multiple
hibernation/resume cycles) and by Amazon with positive results.

[Fix]

Revert the old xen/hibernation patch set + apply the new patch set.

[Regression potential]

All the changes are touching the Xen (guest) code and hibernation,
so we can only see potential regressions in these subsystems.

--

The following changes since commit 497a6691ca053fcb53b0a971317be9736c54f675:

  UBUNTU: Ubuntu-aws-5.8.0-1024.26 (2021-02-10 15:04:42 -0600)

are available in the Git repository at:

  git://git.launchpad.net/~arighi/ubuntu/+source/linux-aws/+git/groovy f7396c3d5475959ae21011425f39bcaf02cb91f1

for you to fetch changes up to f7396c3d5475959ae21011425f39bcaf02cb91f1:

  UBUNTU: SAUCE: x86: tsc: avoid system instability in hibernation (2021-02-24 15:10:41 +0100)

----------------------------------------------------------------
Anchal Agarwal (3):
      UBUNTU: SAUCE: x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume
      UBUNTU: SAUCE: xen: Introduce wrapper for save/restore sched clock offset
      UBUNTU: SAUCE: xen: Update sched clock offset to avoid system instability in hibernation

Andrea Righi (11):
      Revert "UBUNTU: SAUCE: xen: Update sched clock offset to avoid system instability in hibernation"
      Revert "UBUNTU: SAUCE: xen: Introduce wrapper for save/restore sched clock offset"
      Revert "UBUNTU: SAUCE: x86/xen: save and restore steal clock"
      Revert "UBUNTU: SAUCE: xen/time: introduce xen_{save,restore}_steal_clock"
      Revert "UBUNTU: SAUCE: xen-netfront: add callbacks for PM suspend and hibernation"
      Revert "UBUNTU: SAUCE: xen-blkfront: add callbacks for PM suspend and hibernation"
      Revert "UBUNTU: SAUCE: x86/xen: add system core suspend and resume callbacks"
      Revert "UBUNTU: SAUCE: x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume"
      Revert "UBUNTU: SAUCE: xenbus: add freeze/thaw/restore callbacks support"
      Revert "UBUNTU: SAUCE: xen/manage: keep track of the on-going suspend mode"
      UBUNTU: SAUCE: xen-netfront: prevent unnecessary close on hibernate

Eduardo Valentin (1):
      UBUNTU: SAUCE: x86: tsc: avoid system instability in hibernation

Munehisa Kamata (7):
      UBUNTU: SAUCE: xen/manage: keep track of the on-going suspend mode
      UBUNTU: SAUCE: xenbus: add freeze/thaw/restore callbacks support
      UBUNTU: SAUCE: x86/xen: add system core suspend and resume callbacks
      UBUNTU: SAUCE: xen-netfront: add callbacks for PM suspend and hibernation support
      UBUNTU: SAUCE: xen-blkfront: add callbacks for PM suspend and hibernation
      UBUNTU: SAUCE: xen/time: introduce xen_{save,restore}_steal_clock
      UBUNTU: SAUCE: x86/xen: save and restore steal clock

 arch/x86/kernel/tsc.c             | 29 +++++++++++++++++++
 drivers/block/xen-blkfront.c      | 61 +++++++++++++++++++--------------------
 drivers/net/xen-netfront.c        | 11 ++++++-
 drivers/xen/xenbus/xenbus_probe.c | 19 ++++++------
 include/linux/sched/clock.h       |  5 ++++
 kernel/sched/clock.c              |  4 +--
 6 files changed, 86 insertions(+), 43 deletions(-)