[PATCH v4 00/25] KVM: arm64: Introduce pKVM hyp VM and vCPU state at EL2

[Will Deacon]

Hi everyone,

This is version four of the patches previously posted at:

  Mega-patch: https://lore.kernel.org/kvmarm/20220519134204.5379-1-will@kernel.org/
  v2: https://lore.kernel.org/all/20220630135747.26983-1-will@kernel.org/
  v3: https://lore.kernel.org/kvmarm/20220914083500.5118-1-will@kernel.org/

This series extends the pKVM EL2 code so that it can dynamically
instantiate and manage VM data structures without the host being able to
access them directly. These structures consist of a hyp VM, a set of hyp
vCPUs and the stage-2 page-table for the MMU. The pages used to hold the
hypervisor structures are returned to the host when the VM is destroyed.

There are only a few small changes for v4:

  * Fixed missing cache maintenance when reclaiming guest pages on a system
    with the FWB ("Force WriteBack") CPU feature
  * Added a comment about locking requirements for refcount manipulation
  * Fixed a kbuild robot complaint when using 52-bit physical addresses
  * Added Vincent's Tested-by for the series
  * Added Oliver's Reviewed-by for the first patch
  * Rebased onto 6.1-rc1

One big change since v3 is that Quentin's pKVM "technical deep dive" talk
from this year's KVM forum is now online and hopefully provides an
enjoyable narrative to this series:

  https://www.youtube.com/watch?v=9npebeVFbFw

There are still a bunch of extra patches needed to achieve guest/host
isolation, but that follow-up work is largely stalled pending resolution
of the guest private memory API (although KVM forum provided an
excellent venue to iron some of those details out!):

  https://lore.kernel.org/kvm/20220915142913.2213336-1-chao.p.peng@linux.intel.com/T/#t

The last patch remains "RFC" as it's primarily intended for testing and
I couldn't think of a better way to flag it.

Cheers,

Will, Quentin, Fuad and Marc

Cc: Sean Christopherson <seanjc at google.com>
Cc: Will Deacon <will at kernel.org>
Cc: Vincent Donnefort <vdonnefort at google.com>
Cc: Alexandru Elisei <alexandru.elisei at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: James Morse <james.morse at arm.com>
Cc: Chao Peng <chao.p.peng at linux.intel.com>
Cc: Quentin Perret <qperret at google.com>
Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Fuad Tabba <tabba at google.com>
Cc: Oliver Upton <oliver.upton at linux.dev>
Cc: Marc Zyngier <maz at kernel.org>

Cc: kernel-team at android.com
Cc: kvm at vger.kernel.org
Cc: kvmarm at lists.linux.dev
Cc: linux-arm-kernel at lists.infradead.org

--->8

Fuad Tabba (3):
  KVM: arm64: Add hyp_spinlock_t static initializer
  KVM: arm64: Add infrastructure to create and track pKVM instances at
    EL2
  KVM: arm64: Instantiate pKVM hypervisor VM and vCPU structures from
    EL1

Quentin Perret (15):
  KVM: arm64: Move hyp refcount manipulation helpers to common header
    file
  KVM: arm64: Allow attaching of non-coalescable pages to a hyp pool
  KVM: arm64: Back the hypervisor 'struct hyp_page' array for all memory
  KVM: arm64: Fix-up hyp stage-1 refcounts for all pages mapped at EL2
  KVM: arm64: Implement do_donate() helper for donating memory
  KVM: arm64: Prevent the donation of no-map pages
  KVM: arm64: Add helpers to pin memory shared with the hypervisor at
    EL2
  KVM: arm64: Add per-cpu fixmap infrastructure at EL2
  KVM: arm64: Add generic hyp_memcache helpers
  KVM: arm64: Consolidate stage-2 initialisation into a single function
  KVM: arm64: Instantiate guest stage-2 page-tables at EL2
  KVM: arm64: Return guest memory from EL2 via dedicated teardown
    memcache
  KVM: arm64: Unmap 'kvm_arm_hyp_percpu_base' from the host
  KVM: arm64: Explicitly map 'kvm_vgic_global_state' at EL2
  KVM: arm64: Don't unnecessarily map host kernel sections at EL2

Will Deacon (7):
  KVM: arm64: Unify identifiers used to distinguish host and hypervisor
  KVM: arm64: Include asm/kvm_mmu.h in nvhe/mem_protect.h
  KVM: arm64: Rename 'host_kvm' to 'host_mmu'
  KVM: arm64: Initialise hypervisor copies of host symbols
    unconditionally
  KVM: arm64: Provide I-cache invalidation by virtual address at EL2
  KVM: arm64: Maintain a copy of 'kvm_arm_vmid_bits' at EL2
  KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()

 arch/arm64/include/asm/kvm_arm.h              |   2 +-
 arch/arm64/include/asm/kvm_asm.h              |   7 +-
 arch/arm64/include/asm/kvm_host.h             |  73 ++-
 arch/arm64/include/asm/kvm_hyp.h              |   3 +
 arch/arm64/include/asm/kvm_mmu.h              |   2 +-
 arch/arm64/include/asm/kvm_pgtable.h          |  22 +
 arch/arm64/include/asm/kvm_pkvm.h             |  38 ++
 arch/arm64/kernel/image-vars.h                |  15 -
 arch/arm64/kvm/arm.c                          |  61 ++-
 arch/arm64/kvm/hyp/hyp-constants.c            |   3 +
 arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  25 +-
 arch/arm64/kvm/hyp/include/nvhe/memory.h      |  27 +
 arch/arm64/kvm/hyp/include/nvhe/mm.h          |  18 +-
 arch/arm64/kvm/hyp/include/nvhe/pkvm.h        |  74 +++
 arch/arm64/kvm/hyp/include/nvhe/spinlock.h    |  10 +-
 arch/arm64/kvm/hyp/nvhe/cache.S               |  11 +
 arch/arm64/kvm/hyp/nvhe/hyp-main.c            | 110 +++-
 arch/arm64/kvm/hyp/nvhe/hyp-smp.c             |   2 +
 arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 502 ++++++++++++++++--
 arch/arm64/kvm/hyp/nvhe/mm.c                  | 158 +++++-
 arch/arm64/kvm/hyp/nvhe/page_alloc.c          |  28 +-
 arch/arm64/kvm/hyp/nvhe/pkvm.c                | 444 ++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/setup.c               |  96 ++--
 arch/arm64/kvm/hyp/pgtable.c                  |  21 +-
 arch/arm64/kvm/mmu.c                          |  55 +-
 arch/arm64/kvm/pkvm.c                         | 138 ++++-
 arch/arm64/kvm/reset.c                        |  29 -
 27 files changed, 1758 insertions(+), 216 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/include/nvhe/pkvm.h

-- 
2.38.0.413.g74048e4d9e-goog