KVM supports mapping VM_IO and VM_PFNMAP memory into the guest by using follow_pte in gfn_to_pfn. However, the resolved pfns may not have assoicated struct pages, so they should not be passed to pfn_to_page. This series removes such calls from the x86 and arm64 secondary MMU. To do this, this series modifies gfn_to_pfn to return a struct page in addition to a pfn, if the hva was resolved by gup. This allows the caller to call put_page only when necessated by gup. This series provides a helper function that unwraps the new return type of gfn_to_pfn to provide behavior identical to the old behavior. As I have no hardware to test powerpc/mips changes, the function is used there for minimally invasive changes. Additionally, as gfn_to_page and gfn_to_pfn_cache are not integrated with mmu notifier, they cannot be easily changed over to only use pfns. This addresses CVE-2021-22543 on x86 and arm64. David Stevens (6): KVM: x86/mmu: release audited pfns KVM: mmu: also return page from gfn_to_pfn KVM: x86/mmu: avoid struct page in MMU KVM: arm64/mmu: avoid struct page in MMU KVM: mmu: remove over-aggressive warnings drm/i915/gvt: use gfn_to_pfn's page instead of pfn arch/arm64/kvm/mmu.c | 42 +++++---- arch/mips/kvm/mmu.c | 3 +- arch/powerpc/kvm/book3s.c | 3 +- arch/powerpc/kvm/book3s_64_mmu_hv.c | 5 +- arch/powerpc/kvm/book3s_64_mmu_radix.c | 5 +- arch/powerpc/kvm/book3s_hv_uvmem.c | 4 +- arch/powerpc/kvm/e500_mmu_host.c | 2 +- arch/x86/kvm/mmu/mmu.c | 60 ++++++------ arch/x86/kvm/mmu/mmu_audit.c | 13 ++- arch/x86/kvm/mmu/mmu_internal.h | 3 +- arch/x86/kvm/mmu/paging_tmpl.h | 36 +++++--- arch/x86/kvm/mmu/tdp_mmu.c | 7 +- arch/x86/kvm/mmu/tdp_mmu.h | 4 +- arch/x86/kvm/x86.c | 9 +- drivers/gpu/drm/i915/gvt/gtt.c | 12 ++- drivers/gpu/drm/i915/gvt/hypercall.h | 3 +- drivers/gpu/drm/i915/gvt/kvmgt.c | 12 +-- drivers/gpu/drm/i915/gvt/mpt.h | 8 +- include/linux/kvm_host.h | 27 ++++-- include/linux/kvm_types.h | 5 + virt/kvm/kvm_main.c | 123 +++++++++++++------------ 21 files changed, 212 insertions(+), 174 deletions(-) -- 2.32.0.93.g670b81a890-goog
