KVM: guest_memfd: Pass index, not gfn, to __kvm_gmem_get_pfn()

Refactor guest_memfd usage of __kvm_gmem_get_pfn() to pass the index into
the guest_memfd file instead of the gfn, i.e. resolve the index based on
the slot+gfn in the caller instead of in __kvm_gmem_get_pfn().  This will
allow kvm_gmem_get_pfn() to retrieve and return the specific "struct page",
which requires the index into the folio, without a redoing the index
calculation multiple times (which isn't costly, just hard to follow).

Opportunistically add a kvm_gmem_get_index() helper to make the copy+pasted
code easier to understand.

Signed-off-by: Sean Christopherson <[email protected]>
Tested-by: Dmitry Osipenko <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Message-ID: <[email protected]>

0 files changed, 0 insertions, 0 deletions