[PATCH v3 0/2] KVM: PPC: Book3S HV: Nested guest HFSCR changes

[Fabiano Rosas <farosas@linux.ibm.com>]

Applied Nick's suggestions and added a new patch for the Cause bits
issue.

I'm thinking maybe the approach of crashing L1 when L2 tries to access
a facility that L0 has denied is too heavy-handed. But on the other
hand, if L1 were to access the facility itself, the same thing would
happen and L2 runs "inside of L1" in a sense.

Currently, both L0 and L1s handle only msgsndp. All other HV Facility
Unavailable causes are already met with a Program interrupt.

Changes since v2:

- removed the sanitise functions
- moved the entry code into a new load_l2_hv_regs and the exit code
  into the existing save_hv_return_state
- new patch: removes the cause bits when L0 has disabled the
  corresponding facility

v2:

- made the change more generic, not only applies to hfscr anymore;
- sanitisation is now done directly on the vcpu struct, l2_hv is left unchanged;

https://lkml.kernel.org/r/20210406214645.3315819-1-farosas@linux.ibm.com

v1:
https://lkml.kernel.org/r/20210305231055.2913892-1-farosas@linux.ibm.com

Fabiano Rosas (2):
  KVM: PPC: Book3S HV: Sanitise vcpu registers in nested path
  KVM: PPC: Book3S HV: Stop forwarding all HFSCR cause bits to L1

 arch/powerpc/kvm/book3s_hv_nested.c | 72 ++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 21 deletions(-)

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2.29.2