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

Steven Price
2024-04-12T08:44:58Z

Select KVM_GENERIC_PRIVATE_MEM and provide the necessary support
functions.

Signed-off-by: Steven Price <steven.price@arm.com>
---
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