[Intel-gfx] [PATCH 0/6] KVM: Remove uses of struct page from x86 and arm64 MMU

David Stevens
2021-06-24T03:59:19Z

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