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authorBen Gardon <bgardon@google.com>2020-10-14 11:26:54 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2020-10-23 03:42:12 -0400
commit1d8dd6b3f12b03f617820a9ebc19cc2fabf59ce9 (patch)
tree3ef06af72f4d5e6a8d331b631f73eba4c5ef0144
parentf8e144971c6834fa1e171be4cd8026f8bc537bca (diff)
downloadlinux-stericsson-1d8dd6b3f12b03f617820a9ebc19cc2fabf59ce9.tar.gz
kvm: x86/mmu: Support changed pte notifier in tdp MMU
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@google.com> Message-Id: <20201014182700.2888246-15-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c9
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c56
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.h3
3 files changed, 67 insertions, 1 deletions
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 */