Re: [RFC PATCH v2 3/6] KVM: x86/mmu: Pass round full 64-bit error code for the KVM page fault

From: Huang, Kai
Date: Thu Jun 22 2023 - 19:28:30 EST


On Thu, 2023-06-22 at 16:16 -0700, Yamahata, Isaku wrote:
> The upper 32 bits of error code are discarded at kvm_mmu_page_fault()
> by lower_32_bits().  Now it's passed down as full 64 bits.
> Because only FNAME(page_fault) depends on it, move lower_32_bits() into
> FNAME(page_fault).

I haven't looked into the code yet, but the last sentence around
FNAME(page_fault) doesn't make a lot sense IIUC?

For instance, we can have a shadow EPT table when EPT is enabled in L0 and
exposed to L1. If we want to pass 64-bit error code to the handler, how can
FRAME(page_fault)() depend on the lower 32-bit value?