[PATCH v2 42/43] arm64: kvm: Expose support for private memory

[Steven Price <steven.price@xxxxxxx>]

Select KVM_GENERIC_PRIVATE_MEM and provide the necessary support
functions.

Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
 arch/arm64/include/asm/kvm_host.h |  4 ++++
 arch/arm64/kvm/Kconfig            |  1 +
 arch/arm64/kvm/arm.c              |  5 +++++
 arch/arm64/kvm/mmu.c              | 19 +++++++++++++++++++
 4 files changed, 29 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 902923402f6e..93de7f5009fe 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1259,6 +1259,10 @@ static inline bool kvm_vm_is_protected(struct kvm *kvm)
 	return false;
 }
 
+#ifdef CONFIG_KVM_PRIVATE_MEM
+bool kvm_arch_has_private_mem(struct kvm *kvm);
+#endif
+
 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
 
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 58f09370d17e..8da57e74c86a 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -37,6 +37,7 @@ menuconfig KVM
 	select HAVE_KVM_VCPU_RUN_PID_CHANGE
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
+	select KVM_GENERIC_PRIVATE_MEM
 	help
 	  Support hosting virtualized guest machines.
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 2dd014d3c366..a66d0a6eb4fa 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -89,6 +89,11 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
+bool kvm_arch_has_private_mem(struct kvm *kvm)
+{
+	return kvm_is_realm(kvm);
+}
+
 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			    struct kvm_enable_cap *cap)
 {
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 48c957e21c83..808bceebad4d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2171,6 +2171,25 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 	return ret;
 }
 
+bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
+					struct kvm_gfn_range *range)
+{
+	WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm));
+	return false;
+}
+
+bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,
+					 struct kvm_gfn_range *range)
+{
+	WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm));
+
+	if (range->arg.attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE)
+		range->only_shared = true;
+	kvm_unmap_gfn_range(kvm, range);
+
+	return false;
+}
+
 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 }
-- 
2.34.1