[PATCH 0/9] kvm: s390: Add PV dump support

[Janosch Frank <frankja@linux.ibm.com>]

Sometimes dumping inside of a VM fails, is unavailable or doesn't
yield the required data. For these occasions we dump the VM from the
outside, writing memory and cpu data to a file.

Up to now PV guests only supported dumping from the inside of the
guest through dumpers like KDUMP. A PV guest can be dumped from the
hypervisor but the data will be stale and / or encrypted.

To get the actual state of the PV VM we need the help of the
Ultravisor who safeguards the VM state. New UV calls have been added
to initialize the dump, dump storage state data, dump cpu data and
complete the dump process.


Notes:
I'm still pondering adding a lock to the dumping PV struct member to
make absolutely sure that we can't run into the validity even if
userspace tries to achieve getting it.

I chose not to document the dump data provided by the Ultravisor since
KVM doesn't interprete it in any way. We're currently searching for a
location and enough cycles to make it available to all.

Janosch Frank (9):
  s390x: Add SE hdr query information
  s390: uv: Add dump fields to query
  KVM: s390: pv: Add query interface
  KVM: s390: pv: Add dump support definitions
  KVM: s390: pv: Add query dump information
  kvm: s390: Add configuration dump functionality
  kvm: s390: Add CPU dump functionality
  Documentation: virt: Protected virtual machine dumps
  Documentation/virt/kvm/api.rst: Add protvirt dump/info api
    descriptions

 Documentation/virt/kvm/api.rst          | 129 +++++++++++-
 Documentation/virt/kvm/index.rst        |   1 +
 Documentation/virt/kvm/s390-pv-dump.rst |  60 ++++++
 arch/s390/boot/uv.c                     |   4 +
 arch/s390/include/asm/kvm_host.h        |   1 +
 arch/s390/include/asm/uv.h              |  45 +++-
 arch/s390/kernel/uv.c                   |  53 +++++
 arch/s390/kvm/kvm-s390.c                | 267 ++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.h                |   3 +
 arch/s390/kvm/pv.c                      | 131 ++++++++++++
 include/uapi/linux/kvm.h                |  53 +++++
 11 files changed, 744 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/virt/kvm/s390-pv-dump.rst

-- 
2.32.0