[Qemu-arm] [PATCH 00/10] target/arm: Some pieces of support for 32-bit Hyp mode

[Peter Maydell]

Now we have virtualization support in the GICv2 emulation,
I thought I'd have a look at how much we were still missing
for being able to enable EL2 support for AArch32.
This set of patches fixes some minor missing pieces:
 * various small bugs in cp15 registers or places where
   we were missing the 32-bit version of a 64-bit register
 * a bugfix for MSR/MRS (banked), which were not allowing
   Hyp mode to access ELR_Hyp
 * implementation of the ERET instruction for A32/T32
 * support for taking exceptions to Hyp mode (the largest
   of these missing bits)

This isn't complete, but I thought I'd push these patches
out for review. My test setup is that I have another
couple of patches, one which fixes up hw/arm/boot.c to
boot AArch32 kernels in Hyp mode if it exists, and one
which sets ARM_FEATURE_EL2 on our A15 model. With those I
can get an outer kernel to boot with KVM support and try
to run an inner guest kernel. The inner kernel boots OK
but gets random segfaults in its userspace -- I haven't
tracked down why this is yet...

Some bits that are definitely missing:
 * ATS1HR, ATS1HW address translation ops
 * I need to check that the trap semantics for AArch32
   regs line up with their AArch64 counterparts

I also noticed that we fail to implement really quite a lot
of the HCR_EL2 trap semantics for either AArch64 or AArch32,
to the extent that I'm surprised that nested guests work
under AArch64 :-)

This patchset is based on top of my target-arm.for-3.1
branch.

thanks
-- PMM

Peter Maydell (10):
  target/arm: Correct typo in HAMAIR1 regdef name
  target/arm: Add missing .cp = 15 to HMAIR1 and HAMAIR1 regdefs
  target/arm: Implement RAZ/WI HACTLR2
  target/arm: Implement AArch32 HVBAR
  target/arm: Implement AArch32 HCR and HCR2
  target/arm: Implement AArch32 Hyp FARs
  target/arm: Implement ESR_EL2/HSR for AArch32 and no-EL2
  target/arm: Permit accesses to ELR_Hyp from Hyp mode via MSR/MRS
    (banked)
  target/arm: Implement AArch32 ERET instruction
  target/arm: Implement support for taking exceptions to Hyp mode

 target/arm/helper.c    | 226 ++++++++++++++++++++++++++++++++++-------
 target/arm/op_helper.c |  22 ++--
 target/arm/translate.c |  41 +++++++-
 3 files changed, 236 insertions(+), 53 deletions(-)

-- 
2.18.0