[PATCH v13 0/8] MTE support for KVM guest

[Steven Price]

This series adds support for using the Arm Memory Tagging Extensions
(MTE) in a KVM guest.

Changes since v12[1]:

 * Use DEFINE_SPINLOCK() to define tag_sync_lock.

 * Refactor mte_sync_tags() to take the old PTE value rather than a
   pointer to the PTE. The checks in set_pte_at() are also strengthed to
   avoid the function call when possible.

 * Fix prefix on a couple of patches ("arm64: kvm" -> "KVM: arm64").

 * Reorder arguments to sanitise_mte_tags() ("size, pfn" -> "pfn,
   size").

 * Add/improve comments in several places.

 * Report the host's sanitised version of ID_AA64PFR1_EL1:MTE rather
   than making up one for the guest.

 * Insert ISB at the end of mte_switch_to_hyp macro.

 * Drop the definition of CPU_TFSRE0_EL1 in asm-offsets.c as it isn't
   used anymore.

 * Prevent creation of 32 bit vCPUs when MTE is enabled for the guest
   (and document it).

 * Move kvm_vm_ioctl_mte_copy_tags() to guest.c.

 * Reject ZONE_DEVICE memory in kvm_vm_ioctl_mte_copy_tags() and
   correctly handle pages where PG_mte_tagged hasn't been set yet.

 * Define MTE_GRANULES_PER_PAGE rather than open coding the divison
   PAGE_SIZE / MTE_GRANULE_SIZE.

 * Correct the definition of struct kvm_arm_copy_mte_tags in the docs.
   Also avoid mentioning MTE_GRANULE_SIZE as it isn't exported to
   userspace.

[1] https://lore.kernel.org/r/20210517123239.8025-1-steven.price@arm.com/

Catalin Marinas (1):
  arm64: Handle MTE tags zeroing in __alloc_zeroed_user_highpage()

Steven Price (7):
  arm64: mte: Handle race when synchronising tags
  arm64: mte: Sync tags for pages where PTE is untagged
  KVM: arm64: Introduce MTE VM feature
  KVM: arm64: Save/restore MTE registers
  KVM: arm64: Expose KVM_ARM_CAP_MTE
  KVM: arm64: ioctl to fetch/store tags in a guest
  KVM: arm64: Document MTE capability and ioctl

 Documentation/virt/kvm/api.rst             | 52 ++++++++++++++
 arch/arm64/include/asm/kvm_emulate.h       |  3 +
 arch/arm64/include/asm/kvm_host.h          | 12 ++++
 arch/arm64/include/asm/kvm_mte.h           | 68 +++++++++++++++++++
 arch/arm64/include/asm/mte-def.h           |  1 +
 arch/arm64/include/asm/mte.h               |  4 +-
 arch/arm64/include/asm/page.h              |  6 +-
 arch/arm64/include/asm/pgtable.h           | 22 +++++-
 arch/arm64/include/asm/sysreg.h            |  3 +-
 arch/arm64/include/uapi/asm/kvm.h          | 11 +++
 arch/arm64/kernel/asm-offsets.c            |  2 +
 arch/arm64/kernel/mte.c                    | 37 ++++++++--
 arch/arm64/kvm/arm.c                       | 16 +++++
 arch/arm64/kvm/guest.c                     | 79 ++++++++++++++++++++++
 arch/arm64/kvm/hyp/entry.S                 |  7 ++
 arch/arm64/kvm/hyp/exception.c             |  3 +-
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 21 ++++++
 arch/arm64/kvm/mmu.c                       | 48 ++++++++++++-
 arch/arm64/kvm/reset.c                     |  3 +-
 arch/arm64/kvm/sys_regs.c                  | 32 +++++++--
 arch/arm64/mm/fault.c                      | 21 ++++++
 include/uapi/linux/kvm.h                   |  2 +
 22 files changed, 431 insertions(+), 22 deletions(-)
 create mode 100644 arch/arm64/include/asm/kvm_mte.h

-- 
2.20.1