diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-12-06 15:57:21 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-01-08 18:16:05 +0100 |
| commit | cbe1e6f035523b5fd29e44e18b82081b33d1f3f3 (patch) | |
| tree | 23b9c44ca55a85e2afba924c91c039b77c9c9f5f /arch/x86/kvm/mmu | |
| parent | 39ca1ecb784b29965fd780bed1e8a3792a086a29 (diff) | |
KVM: x86/mmu: Incorporate guest's page level into max level for shadow MMU
Restrict the max level for a shadow page based on the guest's level
instead of capping the level after the fact for host-mapped huge pages,
e.g. hugetlbfs pages. Explicitly capping the max level using the guest
mapping level also eliminates FNAME(page_fault)'s subtle dependency on
THP only supporting 2mb pages.
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu')
| -rw-r--r-- | arch/x86/kvm/mmu/paging_tmpl.h | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 1938a6e4e631..7d57ec576df0 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -773,7 +773,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, struct guest_walker walker; int r; kvm_pfn_t pfn; - int level = PT_PAGE_TABLE_LEVEL; + int level; unsigned long mmu_seq; bool map_writable, is_self_change_mapping; bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) && @@ -818,18 +818,14 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, &walker, user_fault, &vcpu->arch.write_fault_to_shadow_pgtable); - max_level = lpage_disallowed ? PT_PAGE_TABLE_LEVEL : - PT_MAX_HUGEPAGE_LEVEL; - - if (walker.level >= PT_DIRECTORY_LEVEL && !is_self_change_mapping) { - level = mapping_level(vcpu, walker.gfn, &max_level); - if (likely(max_level > PT_DIRECTORY_LEVEL)) { - level = min(walker.level, level); - walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); - } - } else { + if (lpage_disallowed || is_self_change_mapping) max_level = PT_PAGE_TABLE_LEVEL; - } + else + max_level = walker.level; + + level = mapping_level(vcpu, walker.gfn, &max_level); + if (level > PT_PAGE_TABLE_LEVEL) + walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1); mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb(); |