[PATCH 00/15] KVM: arm64: Debug cleanups

[Oliver Upton <oliver.upton@linux.dev>]

The debug code has become a bit difficult to reason about, especially
all the hacks and bandaids for state tracking + trap configuration.

This series reworks the entire mess around using a single enumeration to
track the state of the debug registers (free, guest-owned, host-owned),
using that to drive trap configuration and save/restore.

On top of that, this series wires most of the implementation into vCPU
load/put rather than the main KVM_RUN loop. This has been a long time
coming for VHE, as a lot of the trap configuration and EL1 state gets
loaded into hardware at that point anyway.

The save/restore of the debug registers is simplified quite a bit as
well. KVM will now restore the registers for *any* access rather than
just writes, and keep doing so until the next vcpu_put() instead of
dropping it on the floor after the next exception.

Oliver Upton (15):
  KVM: arm64: Drop MDSCR_EL1_DEBUG_MASK
  KVM: arm64: Get rid of __kvm_get_mdcr_el2() and related warts
  KVM: arm64: Track presence of SPE/TRBE in kvm_host_data instead of
    vCPU
  KVM: arm64: Move host SME/SVE tracking flags to host data
  KVM: arm64: Evaluate debug owner at vcpu_load()
  KVM: arm64: Advance debug_owner state machine for sysreg traps
  KVM: arm64: Clean up KVM_SET_GUEST_DEBUG handler
  KVM: arm64: Select debug state to save/restore based on debug owner
  KVM: arm64: Remove debug tracepoints
  KVM: arm64: Remove vestiges of debug_ptr
  KVM: arm64: Use debug_owner to track if debug regs need save/restore
  KVM: arm64: Reload vCPU for accesses to OSLAR_EL1
  KVM: arm64: Compute MDCR_EL2 at vcpu_load()
  KVM: arm64: Don't hijack guest context MDSCR_EL1
  KVM: arm64: Manage software step state at load/put

 arch/arm64/include/asm/kvm_asm.h           |   5 +-
 arch/arm64/include/asm/kvm_host.h          | 109 ++++---
 arch/arm64/kvm/arm.c                       |  14 +-
 arch/arm64/kvm/debug.c                     | 327 +++++----------------
 arch/arm64/kvm/fpsimd.c                    |  12 +-
 arch/arm64/kvm/guest.c                     |  29 +-
 arch/arm64/kvm/handle_exit.c               |   2 +-
 arch/arm64/kvm/hyp/include/hyp/debug-sr.h  |  10 +-
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h |  42 ++-
 arch/arm64/kvm/hyp/nvhe/debug-sr.c         |  13 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c         |   8 -
 arch/arm64/kvm/hyp/vhe/debug-sr.c          |   5 -
 arch/arm64/kvm/sys_regs.c                  |  44 +--
 13 files changed, 204 insertions(+), 416 deletions(-)


base-commit: 25a8556b540075121c6af2c179fe0c036e8851a2
-- 
2.39.5