From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Rename kvm_tdp_mmu_invalidate_all_roots() to
kvm_tdp_mmu_invalidate_roots(), and make it enum kvm_tdp_mmu_root_types
as an argument.
kvm_tdp_mmu_invalidate_roots() is called with different root types. For
kvm_mmu_zap_all_fast() it only operates on shared roots. But when tearing
down a VM it needs to invalidate all roots. Have the callers only
invalidate the required roots instead of all roots.
Within kvm_tdp_mmu_invalidate_roots(), respect the root type
passed by checking the root type in root iterator.
Suggested-by: Chao Gao <chao.gao@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
---
TDX MMU Prep v3:
- Use root enum instead of process enum (Paolo)
- Squash with "KVM: x86/tdp_mmu: Invalidate correct roots" (Paolo)
- Update comment in kvm_mmu_zap_all_fast() (Paolo)
- Add warning for attempting to invalidate invalid roots (Paolo)
TDX MMU Prep v2:
- Use process enum instead of root
TDX MMU Prep:
- New patch
---
arch/x86/kvm/mmu/mmu.c | 9 +++++++--
arch/x86/kvm/mmu/tdp_mmu.c | 15 +++++++++++++--
arch/x86/kvm/mmu/tdp_mmu.h | 3 ++-
3 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 287dcc2685e4..c5255aa62146 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6414,8 +6414,13 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm)
* write and in the same critical section as making the reload request,
* e.g. before kvm_zap_obsolete_pages() could drop mmu_lock and yield.
*/
- if (tdp_mmu_enabled)
- kvm_tdp_mmu_invalidate_all_roots(kvm);
+ if (tdp_mmu_enabled) {
+ /*
+ * External page tables don't support fast zapping, therefore
+ * their mirrors must be invalidated separately by the caller.
+ */
+ kvm_tdp_mmu_invalidate_roots(kvm, KVM_DIRECT_ROOTS);
+ }
/*
* Notify all vcpus to reload its shadow page table and flush TLB.
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 630e6b6d4bf2..a1ab67a4f41f 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -37,7 +37,7 @@ void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
* for zapping and thus puts the TDP MMU's reference to each root, i.e.
* ultimately frees all roots.
*/
- kvm_tdp_mmu_invalidate_all_roots(kvm);
+ kvm_tdp_mmu_invalidate_roots(kvm, KVM_VALID_ROOTS);
kvm_tdp_mmu_zap_invalidated_roots(kvm);
WARN_ON(atomic64_read(&kvm->arch.tdp_mmu_pages));
@@ -1110,10 +1110,18 @@ void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm)
* Note, kvm_tdp_mmu_zap_invalidated_roots() is gifted the TDP MMU's reference.
* See kvm_tdp_mmu_alloc_root().
*/
-void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm)
+void kvm_tdp_mmu_invalidate_roots(struct kvm *kvm,
+ enum kvm_tdp_mmu_root_types root_types)
{
struct kvm_mmu_page *root;
+ /*
+ * Invalidating invalid roots doesn't make sense, prevent developers from
+ * having to think about it.
+ */
+ if (WARN_ON_ONCE(root_types & KVM_INVALID_ROOTS))
+ root_types &= ~KVM_INVALID_ROOTS;
+
/*
* mmu_lock must be held for write to ensure that a root doesn't become
* invalid while there are active readers (invalidating a root while
@@ -1135,6 +1143,9 @@ void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm)
* or get/put references to roots.
*/
list_for_each_entry(root, &kvm->arch.tdp_mmu_roots, link) {
+ if (!tdp_mmu_root_match(root, root_types))
+ continue;
+
/*
* Note, invalid roots can outlive a memslot update! Invalid
* roots must be *zapped* before the memslot update completes,
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 2903f03a34be..56741d31048a 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -66,7 +66,8 @@ static inline struct kvm_mmu_page *tdp_mmu_get_root(struct kvm_vcpu *vcpu,
bool kvm_tdp_mmu_zap_leafs(struct kvm *kvm, gfn_t start, gfn_t end, bool flush);
bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp);
void kvm_tdp_mmu_zap_all(struct kvm *kvm);
-void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm);
+void kvm_tdp_mmu_invalidate_roots(struct kvm *kvm,
+ enum kvm_tdp_mmu_root_types root_types);
void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm);
int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
--
2.34.1
