[RFC PATCH 25/28] kvm: mmu: Support kvm_zap_gfn_range in the direct MMU

[Ben Gardon <bgardon@google.com>]

Add a function for zapping ranges of GFNs in a memslot to support
kvm_zap_gfn_range for the direct MMU.

Signed-off-by: Ben Gardon <bgardon@google.com>
---
 arch/x86/kvm/mmu.c | 27 +++++++++++++++++++++------
 arch/x86/kvm/mmu.h |  2 ++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ca58b27a17c52..a0c5271ae2381 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -7427,13 +7427,32 @@ void kvm_mmu_uninit_vm(struct kvm *kvm)
 	kvm_mmu_uninit_direct_mmu(kvm);
 }
 
+void kvm_zap_slot_gfn_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+			    gfn_t start, gfn_t end)
+{
+	write_lock(&kvm->mmu_lock);
+	if (kvm->arch.direct_mmu_enabled) {
+		zap_direct_gfn_range(kvm, memslot->as_id, start, end,
+				     MMU_READ_LOCK);
+	}
+
+	if (kvm->arch.pure_direct_mmu) {
+		write_unlock(&kvm->mmu_lock);
+		return;
+	}
+
+	slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
+				PT_PAGE_TABLE_LEVEL, PT_MAX_HUGEPAGE_LEVEL,
+				start, end - 1, true);
+	write_unlock(&kvm->mmu_lock);
+}
+
 void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 {
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;
 	int i;
 
-	write_lock(&kvm->mmu_lock);
 	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
 		slots = __kvm_memslots(kvm, i);
 		kvm_for_each_memslot(memslot, slots) {
@@ -7444,13 +7463,9 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 			if (start >= end)
 				continue;
 
-			slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
-						PT_PAGE_TABLE_LEVEL, PT_MAX_HUGEPAGE_LEVEL,
-						start, end - 1, true);
+			kvm_zap_slot_gfn_range(kvm, memslot, start, end);
 		}
 	}
-
-	write_unlock(&kvm->mmu_lock);
 }
 
 static bool slot_rmap_write_protect(struct kvm *kvm,
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 11f8ec89433b6..4ea8a72c8868d 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -204,6 +204,8 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 }
 
 void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
+void kvm_zap_slot_gfn_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+			    gfn_t start, gfn_t end);
 
 void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
 void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
-- 
2.23.0.444.g18eeb5a265-goog