[v2,00/42] KVM: s390: Add support for protected VMs

Message

Christian Borntraeger Feb. 14, 2020, 10:26 p.m. UTC

mm people: This series contains a "pretty small" common code memory
management change that will allow paging, guest backing with files etc
almost just like normal VMs. It should be a no-op for all architectures
not opting in. And it should be usable for others that also try to get
notified on "the pages are in the process of being used for things like
I/O". At the end of the series are two sample patches as these hooks
seem to be useful for other with error handling/call information.  I
would suggest to keep the patch as is and add the additional things when
intel/arm know exactly what they need.

mm-related patches CCed on linux-mm, the complete list can be found on
the KVM and linux-s390 list. 

Andrew, any chance to either take " mm:gup/writeback: add callbacks for
inaccessible pages" or ACK so that I can take it?

Overview
--------
Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
like guest memory and guest registers anymore. Instead the PVMs are
mostly managed by a new entity called Ultravisor (UV), which provides
an API, so KVM and the PV can request management actions.

PVMs are encrypted at rest and protected from hypervisor access while
running. They switch from a normal operation into protected mode, so
we can still use the standard boot process to load a encrypted blob
and then move it into protected mode.

Rebooting is only possible by passing through the unprotected/normal
mode and switching to protected again.

All patches are in the protvirtv4 branch of the korg s390 kvm git
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git/log/?h=protvirtv4

Claudio presented the technology at his presentation at KVM Forum
2019.

https://static.sched.com/hosted_files/kvmforum2019/3b/ibm_protected_vms_s390x.pdf


v-> v2
- rebase on top of kvm/master
- pipe through rc and rrc. This might have created some churn here and
  there
- turn off sclp masking when rebooting into "unsecure"
- memory management simplification
- prefix page handling now via intercept 112
- io interrupt intervention request fix (do not use GISA)
- api.txt conversion to rst
- sample patches on top of mm/gup/writeback
- tons of review feedback
- kvm_uv debug feature fixes and unifications
- ultravisor information for /sys/firmware
- 

RFCv2 -> v1 (you can diff the protvirtv2 and the protvirtv3 branch)
- tons of review feedback integrated (see mail thread)
- memory management now complete and working
- Documentation patches merged
- interrupt patches merged
- CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST removed
- SIDA interface integrated into memop
- for merged patches I removed reviews that were not in all patches

Christian Borntraeger (5):
  KVM: s390/mm: Make pages accessible before destroying the guest
  KVM: s390: protvirt: Add SCLP interrupt handling
  KVM: s390: protvirt: do not inject interrupts after start
  s390/uv: Fix handling of length extensions (already in s390 tree)
  KVM: s390: rstify new ioctls in api.rst

Claudio Imbrenda (6):
  mm:gup/writeback: add callbacks for inaccessible pages
  s390/mm: provide memory management functions for protected KVM guests
  KVM: s390/mm: handle guest unpin events
  example for future extension: mm:gup/writeback: add callbacks for
    inaccessible pages: error cases
  example for future extension: mm:gup/writeback: add callbacks for
    inaccessible pages: source indication
  potential fixup for "s390/mm: provide memory management functions for
    protected KVM guests"

Janosch Frank (25):
  KVM: s390: protvirt: Add UV debug trace
  KVM: s390: add new variants of UV CALL
  KVM: s390: protvirt: Add initial vm and cpu lifecycle handling
  KVM: s390: protvirt: Add KVM api documentation
  KVM: s390: protvirt: Secure memory is not mergeable
  KVM: s390: protvirt: Handle SE notification interceptions
  KVM: s390: protvirt: Instruction emulation
  KVM: s390: protvirt: Handle spec exception loops
  KVM: s390: protvirt: Add new gprs location handling
  KVM: S390: protvirt: Introduce instruction data area bounce buffer
  KVM: s390: protvirt: handle secure guest prefix pages
  KVM: s390: protvirt: Write sthyi data to instruction data area
  KVM: s390: protvirt: STSI handling
  KVM: s390: protvirt: disallow one_reg
  KVM: s390: protvirt: Do only reset registers that are accessible
  KVM: s390: protvirt: Only sync fmt4 registers
  KVM: s390: protvirt: Add program exception injection
  KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling
  KVM: s390: protvirt: UV calls in support of diag308 0, 1
  KVM: s390: protvirt: Report CPU state to Ultravisor
  KVM: s390: protvirt: Support cmd 5 operation state
  KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and
    112
  KVM: s390: protvirt: Add UV cpu reset calls
  DOCUMENTATION: Protected virtual machine introduction and IPL
  s390: protvirt: Add sysfs firmware interface for Ultravisor
    information

Michael Mueller (2):
  KVM: s390: protvirt: Add interruption injection controls
  KVM: s390: protvirt: Implement interruption injection

Ulrich Weigand (1):
  KVM: s390/interrupt: do not pin adapter interrupt pages

Vasily Gorbik (3):
  s390/protvirt: introduce host side setup
  s390/protvirt: add ultravisor initialization
  s390/mm: add (non)secure page access exceptions handlers

 .../admin-guide/kernel-parameters.txt         |   5 +
 Documentation/virt/kvm/api.rst                | 108 +++-
 Documentation/virt/kvm/devices/s390_flic.rst  |  11 +-
 Documentation/virt/kvm/index.rst              |   2 +
 Documentation/virt/kvm/s390-pv-boot.rst       |  83 +++
 Documentation/virt/kvm/s390-pv.rst            | 116 +++++
 MAINTAINERS                                   |   1 +
 arch/s390/boot/Makefile                       |   2 +-
 arch/s390/boot/uv.c                           |  23 +-
 arch/s390/include/asm/gmap.h                  |   6 +
 arch/s390/include/asm/kvm_host.h              | 113 ++++-
 arch/s390/include/asm/mmu.h                   |   2 +
 arch/s390/include/asm/mmu_context.h           |   1 +
 arch/s390/include/asm/page.h                  |   5 +
 arch/s390/include/asm/pgtable.h               |  35 +-
 arch/s390/include/asm/uv.h                    | 251 ++++++++-
 arch/s390/kernel/Makefile                     |   1 +
 arch/s390/kernel/pgm_check.S                  |   4 +-
 arch/s390/kernel/setup.c                      |   9 +-
 arch/s390/kernel/uv.c                         | 412 +++++++++++++++
 arch/s390/kvm/Makefile                        |   2 +-
 arch/s390/kvm/intercept.c                     | 111 +++-
 arch/s390/kvm/interrupt.c                     | 391 ++++++++------
 arch/s390/kvm/kvm-s390.c                      | 479 ++++++++++++++++--
 arch/s390/kvm/kvm-s390.h                      |  40 ++
 arch/s390/kvm/priv.c                          |  11 +-
 arch/s390/kvm/pv.c                            | 295 +++++++++++
 arch/s390/mm/fault.c                          |  78 +++
 arch/s390/mm/gmap.c                           |  65 ++-
 include/linux/gfp.h                           |  12 +
 include/uapi/linux/kvm.h                      |  44 +-
 mm/gup.c                                      |  15 +-
 mm/page-writeback.c                           |   5 +
 33 files changed, 2438 insertions(+), 300 deletions(-)
 create mode 100644 Documentation/virt/kvm/s390-pv-boot.rst
 create mode 100644 Documentation/virt/kvm/s390-pv.rst
 create mode 100644 arch/s390/kernel/uv.c
 create mode 100644 arch/s390/kvm/pv.c