[PATCH v19 024/130] KVM: TDX: Add placeholders for TDX VM/vcpu structure

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Add placeholders TDX VM/vcpu structure that overlays with VMX VM/vcpu
structures.  Initialize VM structure size and vcpu size/align so that x86
KVM common code knows those size irrespective of VMX or TDX.  Those
structures will be populated as guest creation logic develops.

Add helper functions to check if the VM is guest TD and add conversion
functions between KVM VM/VCPU and TDX VM/VCPU.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

---
v19:
- correctly update ops.vm_size, vcpu_size and, vcpu_align by Xiaoyao

v14 -> v15:
- use KVM_X86_TDX_VM

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/kvm/vmx/main.c | 14 ++++++++++++
 arch/x86/kvm/vmx/tdx.c  |  1 +
 arch/x86/kvm/vmx/tdx.h  | 50 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 arch/x86/kvm/vmx/tdx.h

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 18aef6e23aab..e11edbd19e7c 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -5,6 +5,7 @@
 #include "vmx.h"
 #include "nested.h"
 #include "pmu.h"
+#include "tdx.h"
 
 static bool enable_tdx __ro_after_init;
 module_param_named(tdx, enable_tdx, bool, 0444);
@@ -18,6 +19,9 @@ static __init int vt_hardware_setup(void)
 		return ret;
 
 	enable_tdx = enable_tdx && !tdx_hardware_setup(&vt_x86_ops);
+	if (enable_tdx)
+		vt_x86_ops.vm_size = max_t(unsigned int, vt_x86_ops.vm_size,
+					   sizeof(struct kvm_tdx));
 
 	return 0;
 }
@@ -215,8 +219,18 @@ static int __init vt_init(void)
 	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
 	 * exposed to userspace!
 	 */
+	/*
+	 * kvm_x86_ops is updated with vt_x86_ops.  vt_x86_ops.vm_size must
+	 * be set before kvm_x86_vendor_init().
+	 */
 	vcpu_size = sizeof(struct vcpu_vmx);
 	vcpu_align = __alignof__(struct vcpu_vmx);
+	if (enable_tdx) {
+		vcpu_size = max_t(unsigned int, vcpu_size,
+				  sizeof(struct vcpu_tdx));
+		vcpu_align = max_t(unsigned int, vcpu_align,
+				   __alignof__(struct vcpu_tdx));
+	}
 	r = kvm_init(vcpu_size, vcpu_align, THIS_MODULE);
 	if (r)
 		goto err_kvm_init;
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 43c504fb4fed..14ef0ccd8f1a 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -6,6 +6,7 @@
 #include "capabilities.h"
 #include "x86_ops.h"
 #include "x86.h"
+#include "tdx.h"
 
 #undef pr_fmt
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
new file mode 100644
index 000000000000..473013265bd8
--- /dev/null
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __KVM_X86_TDX_H
+#define __KVM_X86_TDX_H
+
+#ifdef CONFIG_INTEL_TDX_HOST
+struct kvm_tdx {
+	struct kvm kvm;
+	/* TDX specific members follow. */
+};
+
+struct vcpu_tdx {
+	struct kvm_vcpu	vcpu;
+	/* TDX specific members follow. */
+};
+
+static inline bool is_td(struct kvm *kvm)
+{
+	return kvm->arch.vm_type == KVM_X86_TDX_VM;
+}
+
+static inline bool is_td_vcpu(struct kvm_vcpu *vcpu)
+{
+	return is_td(vcpu->kvm);
+}
+
+static inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm)
+{
+	return container_of(kvm, struct kvm_tdx, kvm);
+}
+
+static inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu)
+{
+	return container_of(vcpu, struct vcpu_tdx, vcpu);
+}
+#else
+struct kvm_tdx {
+	struct kvm kvm;
+};
+
+struct vcpu_tdx {
+	struct kvm_vcpu	vcpu;
+};
+
+static inline bool is_td(struct kvm *kvm) { return false; }
+static inline bool is_td_vcpu(struct kvm_vcpu *vcpu) { return false; }
+static inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm) { return NULL; }
+static inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu) { return NULL; }
+#endif /* CONFIG_INTEL_TDX_HOST */
+
+#endif /* __KVM_X86_TDX_H */
-- 
2.25.1