From: Ben Gardon <bgardon@xxxxxxxxxx> In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add a hook and handle the change_pte MMU notifier. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx> Message-Id: <20201014182700.2888246-15-bgardon@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 9 +++++- arch/x86/kvm/mmu/tdp_mmu.c | 56 ++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/mmu/tdp_mmu.h | 3 ++ 3 files changed, 67 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 33ec6c4c36d7..41f0354c7489 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1509,7 +1509,14 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end, int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) { - return kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); + int r; + + r = kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); + + if (kvm->arch.tdp_mmu_enabled) + r |= kvm_tdp_mmu_set_spte_hva(kvm, hva, &pte); + + return r; } static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index dd6b8a8f1c93..64e640cfcff9 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -671,3 +671,59 @@ int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva) return kvm_tdp_mmu_handle_hva_range(kvm, hva, hva + 1, 0, test_age_gfn); } + +/* + * Handle the changed_pte MMU notifier for the TDP MMU. + * data is a pointer to the new pte_t mapping the HVA specified by the MMU + * notifier. + * Returns non-zero if a flush is needed before releasing the MMU lock. + */ +static int set_tdp_spte(struct kvm *kvm, struct kvm_memory_slot *slot, + struct kvm_mmu_page *root, gfn_t gfn, gfn_t unused, + unsigned long data) +{ + struct tdp_iter iter; + pte_t *ptep = (pte_t *)data; + kvm_pfn_t new_pfn; + u64 new_spte; + int need_flush = 0; + + WARN_ON(pte_huge(*ptep)); + + new_pfn = pte_pfn(*ptep); + + tdp_root_for_each_pte(iter, root, gfn, gfn + 1) { + if (iter.level != PG_LEVEL_4K) + continue; + + if (!is_shadow_present_pte(iter.old_spte)) + break; + + tdp_mmu_set_spte(kvm, &iter, 0); + + kvm_flush_remote_tlbs_with_address(kvm, iter.gfn, 1); + + if (!pte_write(*ptep)) { + new_spte = kvm_mmu_changed_pte_notifier_make_spte( + iter.old_spte, new_pfn); + + tdp_mmu_set_spte(kvm, &iter, new_spte); + } + + need_flush = 1; + } + + if (need_flush) + kvm_flush_remote_tlbs_with_address(kvm, gfn, 1); + + return 0; +} + +int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address, + pte_t *host_ptep) +{ + return kvm_tdp_mmu_handle_hva_range(kvm, address, address + 1, + (unsigned long)host_ptep, + set_tdp_spte); +} + diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index ddc1bf12d0fc..aeee3ce7b3f4 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -25,4 +25,7 @@ int kvm_tdp_mmu_zap_hva_range(struct kvm *kvm, unsigned long start, int kvm_tdp_mmu_age_hva_range(struct kvm *kvm, unsigned long start, unsigned long end); int kvm_tdp_mmu_test_age_hva(struct kvm *kvm, unsigned long hva); + +int kvm_tdp_mmu_set_spte_hva(struct kvm *kvm, unsigned long address, + pte_t *host_ptep); #endif /* __KVM_X86_MMU_TDP_MMU_H */ -- 2.26.2
