KVM: x86/mmu: Fold max_mapping_level() into kvm_mmu_hugepage_adjust()

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Fold max_mapping_level() into kvm_mmu_hugepage_adjust() now that HugeTLB
mappings are handled in kvm_mmu_hugepage_adjust(), i.e. there isn't a
need to pre-calculate the max mapping level.  Co-locating all hugepage
checks eliminates a memslot lookup, at the cost of performing the
__mmu_gfn_lpage_is_disallowed() checks while holding mmu_lock.

The latency of lpage_is_disallowed() is likely negligible relative to
the rest of the code run while holding mmu_lock, and can be offset to
some extent by eliminating the mmu_gfn_lpage_is_disallowed() check in
set_spte() in a future patch.  Eliminating the check in set_spte() is
made possible by performing the initial lpage_is_disallowed() checks
while holding mmu_lock.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Sean Christopherson 2020-01-08 12:24:46 -08:00 • committed by Paolo Bonzini

parent d32ec81bab

commit 293e306e7f

2 changed files with 30 additions and 37 deletions

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65

arch/x86/kvm/mmu/mmu.c

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2

arch/x86/kvm/mmu/paging_tmpl.h

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