Re: [PATCH] KVM: x86: fix overlap between SPTE_MMIO_MASK and generation

[Paolo Bonzini]

On 21/01/20 22:04, Sean Christopherson wrote:
>> Alternatively, BUILD_BUG_ON((MMIO_SPTE_GEN_HIGH_MASK |
>> MMIO_SPTE_GEN_LOW_MASK) & SPTE_(MMIO and/or SPECIAL)_MASK)
> Or add both BUILD_BUG_ONs.

In the end I decided to revert MMIO_SPTE_GEN_HIGH_START to
PT64_SECOND_AVAIL_BITS_SHIFT (it makes sense since we use it for
shadow_acc_track_saved_bits_shift, and whether to use
shadow_acc_track_saved_bits_shift or MMIO_SPTE_GEN_HIGH_START depends on
the SPTE_SPECIAL_MASK bits) and use Ben's suggested BUILD_BUG_ON.

Paolo