[v3,00/27] KVM: arm64: NV trap forwarding infrastructure

Message

Marc Zyngier Aug. 8, 2023, 11:46 a.m. UTC

As people are getting tired of seeing the full NV series, I've
extracted some of the easy stuff which I'm targeting for 6.6.

This implements the so called "trap forwarding" infrastructure, which
gets used when we take a trap from an L2 guest and that the L1 guest
wants to see the trap for itself.

Most of the series is pretty boring stuff, mostly a long list of
encodings which are mapped to a set of trap bits. I swear they are
correct. Sort of (then are much more correct now that Eric has gone
through them all with a fine comb).

The interesting bit is around how we compute the trap result, which is
pretty complex due to the layers of crap the architecture has piled
over the years (a single op can be trapped by multiple coarse grained
trap bits, or a fine grained trap bit, which may itself be conditioned
by another control bit -- madness).

This also results in some rework of both the FGT stuff (for which I
carry a patch from Mark) and newly introduced the HCRX support.

With that (and the rest of the NV series), FGT gets exposed to guests
and the trapping seems to work as expected.

I'm very inclined to queue this for 6.6, so shout if you think it is a
bad idea!

* From v1 [1]:

  - Lots of fixups all over the map (too many to mention) after Eric's
    fantastic reviewing effort. Hopefully the result is easier to
    understand and less wrong

  - Amended Mark's patch to use the ARM64_CPUID_FIELDS() macro

  - Collected RBs, with thanks.

* From v1 [2]:

  - Another set up fixups thanks to Oliver, Eric and Miguel: TRCID
    bits, duplicate encodings, sanity checking, error handling at boot
    time, spelling mistakes...

  - Split the HFGxTR_EL2 patch in two patches: one that provides the
    FGT infrastructure, and one that provides the HFGxTR_EL2 traps. It
    makes it easier to review and matches the rest of the series.

  - Collected RBs, with thanks

[1] https://lore.kernel.org/all/[e-mail]
[2] https://lore.kernel.org/all/[e-mail]

Marc Zyngier (26):
  arm64: Add missing VA CMO encodings
  arm64: Add missing ERX*_EL1 encodings
  arm64: Add missing DC ZVA/GVA/GZVA encodings
  arm64: Add TLBI operation encodings
  arm64: Add AT operation encodings
  arm64: Add debug registers affected by HDFGxTR_EL2
  arm64: Add missing BRB/CFP/DVP/CPP instructions
  arm64: Add HDFGRTR_EL2 and HDFGWTR_EL2 layouts
  KVM: arm64: Correctly handle ACCDATA_EL1 traps
  KVM: arm64: Add missing HCR_EL2 trap bits
  KVM: arm64: nv: Add FGT registers
  KVM: arm64: Restructure FGT register switching
  KVM: arm64: nv: Add trap forwarding infrastructure
  KVM: arm64: nv: Add trap forwarding for HCR_EL2
  KVM: arm64: nv: Expose FEAT_EVT to nested guests
  KVM: arm64: nv: Add trap forwarding for MDCR_EL2
  KVM: arm64: nv: Add trap forwarding for CNTHCTL_EL2
  KVM: arm64: nv: Add fine grained trap forwarding infrastructure
  KVM: arm64: nv: Add trap forwarding for HFGxTR_EL2
  KVM: arm64: nv: Add trap forwarding for HFGITR_EL2
  KVM: arm64: nv: Add trap forwarding for HDFGxTR_EL2
  KVM: arm64: nv: Add SVC trap forwarding
  KVM: arm64: nv: Add switching support for HFGxTR/HDFGxTR
  KVM: arm64: nv: Expose FGT to nested guests
  KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systems
  KVM: arm64: nv: Add support for HCRX_EL2

Mark Brown (1):
  arm64: Add feature detection for fine grained traps

 arch/arm64/include/asm/kvm_arm.h        |   50 +
 arch/arm64/include/asm/kvm_host.h       |    7 +
 arch/arm64/include/asm/kvm_nested.h     |    2 +
 arch/arm64/include/asm/sysreg.h         |  268 +++-
 arch/arm64/kernel/cpufeature.c          |    7 +
 arch/arm64/kvm/arm.c                    |    4 +
 arch/arm64/kvm/emulate-nested.c         | 1817 +++++++++++++++++++++++
 arch/arm64/kvm/handle_exit.c            |   12 +
 arch/arm64/kvm/hyp/include/hyp/switch.h |  127 +-
 arch/arm64/kvm/nested.c                 |   11 +-
 arch/arm64/kvm/sys_regs.c               |   15 +
 arch/arm64/kvm/trace_arm.h              |   26 +
 arch/arm64/tools/cpucaps                |    1 +
 arch/arm64/tools/sysreg                 |  129 ++
 14 files changed, 2436 insertions(+), 40 deletions(-)