[RFC Part2 PATCH v3 23/26] KVM: X86: Add memory encryption enabled ops

[Brijesh Singh <brijesh.singh@amd.com>]

Extend kvm_x86_ops to add memory_encyption_enabled() ops. It returns a
boolean indicating whether memory encryption is enabled on the VCPU.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a91aadf..a14d4dd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1073,6 +1073,7 @@ struct kvm_x86_ops {
 					struct kvm_memory_encrypt_ram *ram);
 	int (*memory_encryption_unregister_ram)(struct kvm *kvm,
 					struct kvm_memory_encrypt_ram *ram);
+	bool (*memory_encryption_enabled)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index cdb1cf3..0bbd050 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6548,6 +6548,12 @@ static int mem_encrypt_unregister_ram(struct kvm *kvm,
 	return 0;
 }
 
+static bool mem_encrypt_enabled(struct kvm_vcpu *vcpu)
+{
+	return !!(to_svm(vcpu)->vmcb->control.nested_ctl &
+					SVM_NESTED_CTL_SEV_ENABLE);
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -6664,6 +6670,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.memory_encryption_op = svm_memory_encryption_op,
 	.memory_encryption_register_ram = mem_encrypt_register_ram,
 	.memory_encryption_unregister_ram = mem_encrypt_unregister_ram,
+	.memory_encryption_enabled = mem_encrypt_enabled,
+
 };
 
 static int __init svm_init(void)
-- 
2.9.4