diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-04-29 01:04:16 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-20 06:21:36 -0400 |
| commit | 5d49f08c2e08c1f0de1bb0f2e1307ec969451729 (patch) | |
| tree | 6834015a1fa39025ad274f9c0b64609731118695 /arch/x86/kvm/mmu | |
| parent | b14b2690c50e02145bb867dfcde8845eb17aa8a4 (diff) | |
| download | linux-5d49f08c2e08c1f0de1bb0f2e1307ec969451729.tar.bz2 | |
KVM: x86/mmu: Shove refcounted page dependency into host_pfn_mapping_level()
Move the check that restricts mapping huge pages into the guest to pfns
that are backed by refcounted 'struct page' memory into the helper that
actually "requires" a 'struct page', host_pfn_mapping_level(). In
addition to deduplicating code, moving the check to the helper eliminates
the subtle requirement that the caller check that the incoming pfn is
backed by a refcounted struct page, and as an added bonus avoids an extra
pfn_to_page() lookup.
Note, the is_error_noslot_pfn() check in kvm_mmu_hugepage_adjust() needs
to stay where it is, as it guards against dereferencing a NULL memslot in
the kvm_slot_dirty_track_enabled() that follows.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220429010416.2788472-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu')
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 14 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 4 |
2 files changed, 11 insertions, 7 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7ebb97c95da7..27b2a5603496 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2791,8 +2791,8 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, const struct kvm_memory_slot *slot) { - struct page *page = pfn_to_page(pfn); int level = PG_LEVEL_4K; + struct page *page; unsigned long hva; unsigned long flags; pgd_t pgd; @@ -2800,6 +2800,14 @@ static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, pud_t pud; pmd_t pmd; + /* + * Note, @slot must be non-NULL, i.e. the caller is responsible for + * ensuring @pfn isn't garbage and is backed by a memslot. + */ + page = kvm_pfn_to_refcounted_page(pfn); + if (!page) + return PG_LEVEL_4K; + if (!PageCompound(page) && !kvm_is_zone_device_page(page)) return PG_LEVEL_4K; @@ -2884,7 +2892,7 @@ void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault if (unlikely(fault->max_level == PG_LEVEL_4K)) return; - if (is_error_noslot_pfn(fault->pfn) || !kvm_pfn_to_refcounted_page(fault->pfn)) + if (is_error_noslot_pfn(fault->pfn)) return; if (kvm_slot_dirty_track_enabled(slot)) @@ -5996,7 +6004,7 @@ restart: * the guest, and the guest page table is using 4K page size * mapping if the indirect sp has level = 1. */ - if (sp->role.direct && kvm_pfn_to_refcounted_page(pfn) && + if (sp->role.direct && sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, pfn, PG_LEVEL_NUM)) { pte_list_remove(kvm, rmap_head, sptep); diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 1e777b739ac4..1ea40809ef1f 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1750,10 +1750,6 @@ static void zap_collapsible_spte_range(struct kvm *kvm, * be mapped at a higher level. */ pfn = spte_to_pfn(iter.old_spte); - - if (!kvm_pfn_to_refcounted_page(pfn)) - continue; - max_mapping_level = kvm_mmu_max_mapping_level(kvm, slot, iter.gfn, pfn, PG_LEVEL_NUM); |