Re: [RFCv2 00/37] KVM: s390: Add support for protected VMs

[David Hildenbrand <david@redhat.com>]

On 03.02.20 14:19, Christian Borntraeger wrote:
> 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 protvirtv2 branch of the korg s390 kvm git
> (on top of Janoschs reset rework).
> 
> Claudio presented the technology at his presentation at KVM Forum
> 2019.
> 
> This contains a "pretty small" common code memory management change that
> will allow paging, guest backing with files etc almost just like normal
> VMs. Please note that the memory management part will still see some
> changes to deal with a corner case for the adapter interrupt indicator
> pages. So please focus on the non-mm parts (which hopefully has
> everthing addressed in the next version). Claudio will work with Andrea
> regarding this.
> 
> Christian Borntraeger (3):
>   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
> 
> Claudio Imbrenda (3):
>   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
> 
> Janosch Frank (24):
>   DOCUMENTATION: protvirt: Protected virtual machine introduction
>   KVM: s390: add new variants of UV CALL
>   KVM: s390: protvirt: Add initial 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: Only sync fmt4 registers
>   KVM: s390: protvirt: Add program exception injection
>   DOCUMENTATION: protvirt: Diag 308 IPL
>   KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling
>   KVM: s390: protvirt: UV calls diag308 0, 1
>   KVM: s390: protvirt: Report CPU state to Ultravisor
>   KVM: s390: protvirt: Support cmd 5 operation state
>   KVM: s390: protvirt: Add UV debug trace
>   KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and
>     112
>   KVM: s390: protvirt: Add UV cpu reset calls
> 
> Michael Mueller (4):
>   KVM: s390: protvirt: Add interruption injection controls
>   KVM: s390: protvirt: Implement interruption injection
>   KVM: s390: protvirt: Add machine-check interruption injection controls
>   KVM: s390: protvirt: Implement machine-check interruption injection
> 
> Vasily Gorbik (3):
>   s390/protvirt: introduce host side setup
>   s390/protvirt: add ultravisor initialization
>   s390: add (non)secure page access exceptions handlers
> 
>  .../admin-guide/kernel-parameters.txt         |   5 +
>  Documentation/virt/kvm/api.txt                |  62 +++
>  Documentation/virt/kvm/s390-pv-boot.rst       |  64 +++
>  Documentation/virt/kvm/s390-pv.rst            | 103 ++++
>  MAINTAINERS                                   |   1 +
>  arch/s390/boot/Makefile                       |   2 +-
>  arch/s390/boot/uv.c                           |  20 +-
>  arch/s390/include/asm/gmap.h                  |   3 +
>  arch/s390/include/asm/kvm_host.h              | 112 +++-
>  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                    | 265 +++++++++-
>  arch/s390/kernel/Makefile                     |   1 +
>  arch/s390/kernel/pgm_check.S                  |   4 +-
>  arch/s390/kernel/setup.c                      |   7 +-
>  arch/s390/kernel/uv.c                         | 271 ++++++++++
>  arch/s390/kvm/Kconfig                         |  19 +
>  arch/s390/kvm/Makefile                        |   2 +-
>  arch/s390/kvm/diag.c                          |   7 +
>  arch/s390/kvm/intercept.c                     | 107 +++-
>  arch/s390/kvm/interrupt.c                     | 211 ++++++--
>  arch/s390/kvm/kvm-s390.c                      | 486 ++++++++++++++++--
>  arch/s390/kvm/kvm-s390.h                      |  56 ++
>  arch/s390/kvm/priv.c                          |   9 +-
>  arch/s390/kvm/pv.c                            | 293 +++++++++++
>  arch/s390/mm/fault.c                          |  87 ++++
>  arch/s390/mm/gmap.c                           |  63 ++-
>  include/linux/gfp.h                           |   6 +
>  include/uapi/linux/kvm.h                      |  47 +-
>  mm/gup.c                                      |   2 +
>  mm/page-writeback.c                           |   1 +
>  33 files changed, 2217 insertions(+), 142 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
> 

Due to the huge amount of review feedback (which makestime-consuming to
review if one doesn't want to comment the same thing again), I suggest
sending a new RFC rather soon-ish (e.g., on a weekly basis) - if nobody
objects. Would at least make my life easier :)

-- 
Thanks,

David / dhildenb