[PATCH 0/2] KVM: arm64: Handle unsupported guest translation granules

[Wei-Lin Chang]

Hi,

This small series fixes the granule size selection for software stage-1
and stage-2 walks. Previously we treat the guest's TCR/VTCR.TGx as-is
and use the encoded granule size for the walks. However this is
incorrect if the granule sizes are not advertised in the guest's
ID_AA64MMFR0_EL1.TGRAN*. The architecture specifies that when an
unsupported size is programed in TGx, it must be treated as an
implemented size. Fix this by choosing an available one while
prioritizing PAGE_SIZE.

The first patch is a refactor to prepare for the fix, and the fix is
implemented in the second patch. I lightly tested for regressions by
booting up nested guests of each page size.

Thanks!

Wei-Lin Chang (2):
  KVM: arm64: Factor out TG0/1 decoding of VTCR and TCR
  KVM: arm64: Fallback to a supported value for unsupported guest TGx

 arch/arm64/kvm/at.c     | 121 +++++++++++++++++++++++++--------
 arch/arm64/kvm/nested.c | 145 ++++++++++++++++++++++++++++------------
 2 files changed, 194 insertions(+), 72 deletions(-)

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2.43.0