[RFC PATCH v2 03/10] KVM: TDX: Add base implementation for tdx_vm_move_enc_context_from

[Ryan Afranji]

From: Sagi Shahar <sa...@google.com>

This should mostly match the logic in sev_vm_move_enc_context_from.

Signed-off-by: Sagi Shahar <sa...@google.com>
Signed-off-by: Ryan Afranji <afra...@google.com>
---
 arch/x86/kvm/vmx/main.c    | 12 +++++++++++-
 arch/x86/kvm/vmx/tdx.c     | 24 ++++++++++++++++++++++++
 arch/x86/kvm/vmx/x86_ops.h |  1 +
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index d1e02e567b57..125af25fd09a 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -879,6 +879,14 @@ static int vt_gmem_private_max_mapping_level(struct kvm 
*kvm, kvm_pfn_t pfn)
        return 0;
 }
 
+static int vt_move_enc_context_from(struct kvm *kvm, struct kvm *source_kvm)
+{
+       if (!is_td(kvm))
+               return -ENOTTY;
+
+       return tdx_vm_move_enc_context_from(kvm, source_kvm);
+}
+
 #define vt_op(name) vt_##name
 #define vt_op_tdx_only(name) vt_##name
 #else /* CONFIG_KVM_INTEL_TDX */
@@ -1044,7 +1052,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
        .mem_enc_ioctl = vt_op_tdx_only(mem_enc_ioctl),
        .vcpu_mem_enc_ioctl = vt_op_tdx_only(vcpu_mem_enc_ioctl),
 
-       .private_max_mapping_level = 
vt_op_tdx_only(gmem_private_max_mapping_level)
+       .private_max_mapping_level = 
vt_op_tdx_only(gmem_private_max_mapping_level),
+
+       .vm_move_enc_context_from = vt_move_enc_context_from
 };
 
 struct kvm_x86_init_ops vt_init_ops __initdata = {
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index b952bc673271..07583a11d6e3 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -626,6 +626,7 @@ int tdx_vm_init(struct kvm *kvm)
        kvm->arch.has_protected_state = true;
        kvm->arch.has_private_mem = true;
        kvm->arch.disabled_quirks |= KVM_X86_QUIRK_IGNORE_GUEST_PAT;
+       kvm->arch.use_vm_enc_ctxt_op = true;
 
        /*
         * Because guest TD is protected, VMM can't parse the instruction in TD.
@@ -3524,3 +3525,26 @@ int __init tdx_bringup(void)
        enable_tdx = 0;
        return 0;
 }
+
+static __always_inline bool tdx_finalized(struct kvm *kvm)
+{
+       struct kvm_tdx *tdx_kvm = to_kvm_tdx(kvm);
+
+       return tdx_kvm->state == TD_STATE_RUNNABLE;
+}
+
+static int tdx_migrate_from(struct kvm *dst, struct kvm *src)
+{
+       return -EINVAL;
+}
+
+int tdx_vm_move_enc_context_from(struct kvm *kvm, struct kvm *src_kvm)
+{
+       if (!is_td(kvm) || !is_td(src_kvm))
+               return -EINVAL;
+
+       if (tdx_finalized(kvm) || !tdx_finalized(src_kvm))
+               return -EINVAL;
+
+       return tdx_migrate_from(kvm, src_kvm);
+}
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index b4596f651232..001f1540a560 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -164,6 +164,7 @@ void tdx_flush_tlb_current(struct kvm_vcpu *vcpu);
 void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);
 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
 int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn);
+int tdx_vm_move_enc_context_from(struct kvm *kvm, struct kvm *source_kvm);
 #endif
 
 #endif /* __KVM_X86_VMX_X86_OPS_H */
-- 
2.50.0.rc1.591.g9c95f17f64-goog