Re: [PATCH v4 00/36] KVM: s390: Add support for protected VMs

[Christian Borntraeger <borntraeger@de.ibm.com>]

The KVM part is almost done with review and I have now pushed this to
kvms390/next to give some exposure:
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git/log/?h=next

We still need a solution for Patch 1,"mm:gup/writeback: add callbacks for
inaccessible pages".
Andrew, I need your guidance here. Take this via s390kvm with an ACK or
take it via your tree?

Christian




On 24.02.20 12:40, Christian Borntraeger wrote:
> mm-related patches CCed on linux-mm, the complete list can be found on
> the KVM and linux-s390 list. 
> 
> Andrew, any chance to take " mm:gup/writeback: add callbacks for
> inaccessible pages" for 5.7? I can then carry the s390/kvm part. There
> is no build dependency on this patch (just a logical one).  As an
> alternative I can take an ack and carry that patch myself. 
> 
> 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". This time I included error handling and an ACK from Will
> Deacon as well as a Reviewed-by: from David Hildenbrand.
> This patch will be used by
> "[PATCH v4 05/36] s390/mm: provide memory management functions for
> protected KVM guests".
> We need to call into the "make accessible" architecture function when
> the refcount is already increased the writeback bit is set. This will
> make sure that we do not call the reverse function (convert to secure)
> until the host operation has finished.
> 
> 
> 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=protvirtv6
> 
> Claudio presented the technology at his presentation at KVM Forum
> 2019.
> 
> https://static.sched.com/hosted_files/kvmforum2019/3b/ibm_protected_vms_s390x.pdf
> 
> 
> v3 -> v4:
> general
> -------
> - copyright updates
> - Reviewedby + acked by tags
> 
> KVM: s390/interrupt: do not pin adapter interrupt pages
> -------------------------------------------------------
> - more comments
> - get rid of now obsolete adapter parameter
> 
> s390/mm: provide memory management functions for protected KVM guests
> ---------------------------------------------------------------------
> - improved patch description
> 
> KVM: s390: protvirt: Add initial vm and cpu lifecycle handling
> --------------------------------------------------------------
> - rework tweak logic to not use an array
> - remove _VM_ part of the subfunction names of PV_COMMAND
> - merge alloc/create/destroy/dealloc into init/deinit
> - handle cmma deallocation on failures
> - rework error handling to pass along the first rc/rrc if VCPU or VM CREATE/DESTROY fails
> This was tested successfully with error injection and tracing. We do not deallocate on
> destroy failure and we pass along the first rc/rrc when vcpu destroy fails.
> 
>  KVM: s390: protvirt: Add KVM api documentation
> -----------------------------------------------
> - mention new MP_STATE
> - remove "old" interfaces that are no longer in the previous patch
> - move to the end
> 
> KVM: s390: protvirt: Secure memory is not mergeable
> ---------------------------------------------------
> - rebase on new lifecycle patch
> 
> KVM: s390: protvirt: UV calls in support of diag308 0,1
> -------------------------------------------------------
> - remove _VM_ part of the subfunction names of PV_COMMAND
> 
> KVM: s390: rstify new ioctls in api.rst
> ---------------------------------------
> - removed from this patch queue
> 
> 
> 
> v2 -> v3
> - rebase against v5.6-rc2
> - move some checks into the callers
> - typo fixes
> - extend UV query size
> - do a tlb flush when entering/exiting protected mode
> - more comments
> - change interface to PV_ENABLE/DISABLE instead of vcpu/vm
>   create/destroy
> - lockdep checks for *is_protected calls
> - locking improments
> - move facility 161 to qemu
> - checkpatch fixes
> - merged error handling in mm patch
> - removed vcpu pv commands
> - use mp_state for setting the IPL PSW
> 
> 
> v1 -> 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 (4):
>   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
>   KVM: s390: protvirt: introduce and enable KVM_CAP_S390_PROTECTED
> 
> 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):
>   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: 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: 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
>   KVM: s390: protvirt: Add KVM api documentation
> 
> Michael Mueller (1):
>   KVM: s390: protvirt: Implement interrupt 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                |  61 +-
>  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                           |  21 +-
>  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                    | 252 ++++++++-
>  arch/s390/kernel/Makefile                     |   1 +
>  arch/s390/kernel/pgm_check.S                  |   4 +-
>  arch/s390/kernel/setup.c                      |   9 +-
>  arch/s390/kernel/uv.c                         | 413 ++++++++++++++
>  arch/s390/kvm/Makefile                        |   2 +-
>  arch/s390/kvm/diag.c                          |   6 +-
>  arch/s390/kvm/intercept.c                     | 117 +++-
>  arch/s390/kvm/interrupt.c                     | 399 +++++++------
>  arch/s390/kvm/kvm-s390.c                      | 532 +++++++++++++++---
>  arch/s390/kvm/kvm-s390.h                      |  51 +-
>  arch/s390/kvm/priv.c                          |  13 +-
>  arch/s390/kvm/pv.c                            | 298 ++++++++++
>  arch/s390/mm/fault.c                          |  78 +++
>  arch/s390/mm/gmap.c                           |  65 ++-
>  include/linux/gfp.h                           |   6 +
>  include/uapi/linux/kvm.h                      |  43 +-
>  mm/gup.c                                      |  15 +-
>  mm/page-writeback.c                           |   5 +
>  34 files changed, 2461 insertions(+), 312 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
>