[PATCH v11 00/12] In-kernel PSCI v0.2 emulation for KVM ARM/ARM64

[Anup Patel]

Currently, KVM ARM/ARM64 only provides in-kernel emulation of Power State
and Coordination Interface (PSCI) v0.1.

This patchset aims at providing newer PSCI v0.2 for KVM ARM/ARM64 VCPUs
such that it does not break current KVM ARM/ARM64 ABI.

The user space tools (i.e. QEMU or KVMTOOL) will have to explicitly enable
KVM_ARM_VCPU_PSCI_0_2 feature using KVM_ARM_VCPU_INIT ioctl for providing
PSCI v0.2 to VCPUs.

Changlog:

V11:
 - Added more comments to uapi/linux/psci.h
 - Added comment about why we store INTERNAL_FAILURE in r0 (or x0)
   for SYSTEM_OFF and SYSTEM_RESET emulation

V10:
 - Updated PSCI_VERSION_xxx defines in uapi/linux/psci.h
 - Added PSCI_0_2_AFFINITY_LEVEL_xxxx defines in uapi/linux/psci.h
 - Removed PSCI v0.1 related defines from uapi/linux/psci.h
 - Inject undefined exception for all types of errors in PSCI
   emulation (i.e kvm_psci_call(vcpu) < 0)
 - Removed "inline" attribute of kvm_prepare_system_event()
 - Store INTERNAL_FAILURE in r0 (or x0) before exiting to userspace
 - Use MPIDR_LEVEL_BITS in AFFINITY_MASK define
 - Updated comment in kvm_psci_vcpu_suspend() as-per Marc's suggestion

V9:
 - Rename undefined PSCI_VER_xxx defines to PSCI_VERSION_xxx defines

V8:
 - Add #define for possible values of migrate type in uapi/linux/psci.h
 - Simplified psci_affinity_mask() in psci.c
 - Update comments in kvm_psci_vcpu_suspend() to indicate that for KVM
   wakeup events are interrupts.
 - Unconditionally update r0 (or x0) in kvm_psci_vcpu_on()

V7:
 - Make uapi/linux/psci.h inline with Ashwin's patch
   http://www.spinics.net/lists/arm-kernel/msg319090.html
 - Incorporate Rob's suggestions for uapi/linux/psci.h
 - Treat CPU_SUSPEND power-down request to be same as standby
   request. This further simplifies CPU_SUSPEND emulation.

V6:
 - Introduce uapi/linux/psci.h for sharing PSCI defines between
   ARM kernel, ARM64 kernel, KVM ARM/ARM64 and user space
 - Make CPU_SUSPEND emulation similar to WFI emulation

V5:
 - Have separate last patch to advertise KVM_CAP_ARM_PSCI_0_2
 - Use kvm_psci_version() in kvm_psci_vcpu_on()
 - Return ALREADY_ON for PSCI v0.2 CPU_ON if VCPU is not paused
 - Remove per-VCPU suspend context
 - As-per PSCI v0.2 spec, only current CPU can suspend itself

V4:
 - Implement all mandatory functions required by PSCI v0.2

V3:
 - Make KVM_ARM_VCPU_PSCI_0_2 feature experiementatl for now so that
   it fails for user space till all mandatory PSCI v0.2 functions are
   emulated by KVM ARM/ARM64
 - Have separate patch for making KVM_ARM_VCPU_PSCI_0_2 feature available
   to user space. This patch can be defferred for now

V2:
 - Don't rename PSCI return values KVM_PSCI_RET_NI and KVM_PSCI_RET_INVAL
 - Added kvm_psci_version() to get PSCI version available to VCPU
 - Fixed grammer in Documentation/virtual/kvm/api.txt

V1:
 - Initial RFC PATCH

Anup Patel (12):
  KVM: Add capability to advertise PSCI v0.2 support
  ARM/ARM64: KVM: Add common header for PSCI related defines
  ARM/ARM64: KVM: Add base for PSCI v0.2 emulation
  KVM: Documentation: Add info regarding KVM_ARM_VCPU_PSCI_0_2 feature
  ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible
  KVM: Add KVM_EXIT_SYSTEM_EVENT to user space API header
  ARM/ARM64: KVM: Emulate PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET
  ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO
  ARM/ARM64: KVM: Emulate PSCI v0.2 MIGRATE_INFO_TYPE and related
    functions
  ARM/ARM64: KVM: Fix CPU_ON emulation for PSCI v0.2
  ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND
  ARM/ARM64: KVM: Advertise KVM_CAP_ARM_PSCI_0_2 to user space

 Documentation/virtual/kvm/api.txt |   17 +++
 arch/arm/include/asm/kvm_host.h   |    2 +-
 arch/arm/include/asm/kvm_psci.h   |    6 +-
 arch/arm/include/uapi/asm/kvm.h   |   10 +-
 arch/arm/kvm/arm.c                |    1 +
 arch/arm/kvm/handle_exit.c        |   10 +-
 arch/arm/kvm/psci.c               |  235 ++++++++++++++++++++++++++++++++++---
 arch/arm64/include/asm/kvm_host.h |    2 +-
 arch/arm64/include/asm/kvm_psci.h |    6 +-
 arch/arm64/include/uapi/asm/kvm.h |   10 +-
 arch/arm64/kvm/handle_exit.c      |   10 +-
 include/uapi/linux/Kbuild         |    1 +
 include/uapi/linux/kvm.h          |    9 ++
 include/uapi/linux/psci.h         |   90 ++++++++++++++
 14 files changed, 372 insertions(+), 37 deletions(-)
 create mode 100644 include/uapi/linux/psci.h

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1.7.9.5