[PATCH 0/3] KVM: arm64: aarch32 ACTLR accesses

[James Morse <james.morse@arm.com>]

Hello!

Patch 1 fixes an issue where the 32bit and 64bit indexes into copro[]
and sys_regs[] are muddled.

Patch 3 adds support for aarch32 accessing the top 32bits of ACTLR_EL1
via ACTLR2. Support for this register is advertised in ID_MMFR4.AC2, which
doesn't get removed by cpufeature. The register is mandatory from v8.2, but
imp-def before then.

Patch 2 stops the sys_regs[] value we use for emulation being save/restored.
This simplifies patch 3 as the aarch32 helper can rely on the in-memory copy.

I think Patch 1 is stable material, I'm not sure about 2&3.


Bonus cans of worms!:

1. How does this copro[] thing work with a big-endian host?
The cp15_regs emulation look fine as nothing uses vcpu_cp15() to read the
register, but wouldn't prepare_fault32() read the wrong end of the register
when using vcpu_cp15()?

2. How does the 32bit fault injection code work with VHE?
vcpu_cp15() modifies the in-memory copy, surely a vcpu_put() will clobber
everything it did, or fail to restore it when entering the guest.


Thanks,

James Morse (3):
  KVM: arm64: Stop writing aarch32's CSSELR into ACTLR
  KVM: arm64: Stop save/restoring ACTLR_EL1
  KVM: arm64: Add emulation for 32bit guests accessing ACTLR2

 arch/arm64/include/asm/kvm_host.h    |  1 +
 arch/arm64/kvm/hyp/sysreg-sr.c       |  2 --
 arch/arm64/kvm/sys_regs.c            |  8 +++-----
 arch/arm64/kvm/sys_regs_generic_v8.c | 16 +++++++++++++++-
 4 files changed, 19 insertions(+), 8 deletions(-)

-- 
2.20.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm