[PATCH v7 013/102] KVM: TDX: Make TDX VM type supported

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

NOTE: This patch is in position of the patch series for developers to be
able to test codes during the middle of the patch series although this
patch series doesn't provide functional features until the all the patches
of this patch series.  When merging this patch series, this patch can be
moved to the end.

As first step TDX VM support, return that TDX VM type supported to device
model, e.g. qemu.  The callback to create guest TD is vm_init callback for
KVM_CREATE_VM.  Add a place holder function and call a function to
initialize TDX module on demand because in that callback VMX is enabled by
hardware_enable callback (vmx_hardware_enable).

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/kvm/vmx/main.c    | 18 ++++++++++++++++--
 arch/x86/kvm/vmx/tdx.c     |  6 ++++++
 arch/x86/kvm/vmx/vmx.c     |  5 -----
 arch/x86/kvm/vmx/x86_ops.h |  3 ++-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 7be4941e4c4d..47bfa94e538e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -10,6 +10,12 @@
 static bool __read_mostly enable_tdx = IS_ENABLED(CONFIG_INTEL_TDX_HOST);
 module_param_named(tdx, enable_tdx, bool, 0444);
 
+static bool vt_is_vm_type_supported(unsigned long type)
+{
+	return type == KVM_X86_DEFAULT_VM ||
+		(enable_tdx && tdx_is_vm_type_supported(type));
+}
+
 static __init int vt_hardware_setup(void)
 {
 	int ret;
@@ -33,6 +39,14 @@ static int __init vt_post_hardware_enable_setup(void)
 	return 0;
 }
 
+static int vt_vm_init(struct kvm *kvm)
+{
+	if (is_td(kvm))
+		return -EOPNOTSUPP;	/* Not ready to create guest TD yet. */
+
+	return vmx_vm_init(kvm);
+}
+
 struct kvm_x86_ops vt_x86_ops __initdata = {
 	.name = "kvm_intel",
 
@@ -43,9 +57,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.hardware_disable = vmx_hardware_disable,
 	.has_emulated_msr = vmx_has_emulated_msr,
 
-	.is_vm_type_supported = vmx_is_vm_type_supported,
+	.is_vm_type_supported = vt_is_vm_type_supported,
 	.vm_size = sizeof(struct kvm_vmx),
-	.vm_init = vmx_vm_init,
+	.vm_init = vt_vm_init,
 	.vm_destroy = vmx_vm_destroy,
 
 	.vcpu_precreate = vmx_vcpu_precreate,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 9cb36716b0f3..3675f7de2735 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -73,6 +73,12 @@ int __init tdx_module_setup(void)
 	return 0;
 }
 
+bool tdx_is_vm_type_supported(unsigned long type)
+{
+	/* enable_tdx check is done by the caller. */
+	return type == KVM_X86_TDX_VM;
+}
+
 int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
 {
 	u32 max_pa;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5ba62f8b42ce..b30d73d28e75 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7281,11 +7281,6 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
 	return err;
 }
 
-bool vmx_is_vm_type_supported(unsigned long type)
-{
-	return type == KVM_X86_DEFAULT_VM;
-}
-
 #define L1TF_MSG_SMT "L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
 #define L1TF_MSG_L1D "L1TF CPU bug present and virtualization mitigation disabled, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
 
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index a5e85eb4e183..dbfd0e43fd89 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -25,7 +25,6 @@ void vmx_hardware_unsetup(void);
 int vmx_check_processor_compatibility(void);
 int vmx_hardware_enable(void);
 void vmx_hardware_disable(void);
-bool vmx_is_vm_type_supported(unsigned long type);
 int vmx_vm_init(struct kvm *kvm);
 void vmx_vm_destroy(struct kvm *kvm);
 int vmx_vcpu_precreate(struct kvm *kvm);
@@ -131,8 +130,10 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu);
 
 #ifdef CONFIG_INTEL_TDX_HOST
 int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
+bool tdx_is_vm_type_supported(unsigned long type);
 #else
 static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return 0; }
+static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
 #endif
 
 #endif /* __KVM_X86_VMX_X86_OPS_H */
-- 
2.25.1