[PATCH v19 025/130] KVM: TDX: Make TDX VM type supported

isaku.yamahata
2024-02-26T08:27:54Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

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.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/vmx/main.c | 18 ++++++++++++++++--
arch/x86/kvm/vmx/tdx.c | 6 ++++++
arch/x86/kvm/vmx/vmx.c | 6 ------
arch/x86/kvm/vmx/x86_ops.h | 3 ++-
4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index e11edbd19e7c..fa19682b366c 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -10,6 +10,12 @@
static bool enable_tdx __ro_after_init;
module_param_named(tdx, enable_tdx, bool, 0444);

+static bool vt_is_vm_type_supported(unsigned long type)
+{
+ return __kvm_is_vm_type_supported(type) ||
+ (enable_tdx && tdx_is_vm_type_supported(type));
+}
+
static __init int vt_hardware_setup(void)
{
int ret;
@@ -26,6 +32,14 @@ static __init int vt_hardware_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);
+}
+
#define VMX_REQUIRED_APICV_INHIBITS \
(BIT(APICV_INHIBIT_REASON_DISABLE)| \
BIT(APICV_INHIBIT_REASON_ABSENT) | \
@@ -47,9 +61,9 @@ 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 14ef0ccd8f1a..a7e096fd8361 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -24,6 +24,12 @@ static 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;
+}
+
struct tdx_enabled {
cpumask_var_t enabled;
atomic_t err;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2fb1cd2e28a2..d928acc15d0f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7531,12 +7531,6 @@ int vmx_vcpu_create(struct kvm_vcpu *vcpu)
return err;
}

-bool vmx_is_vm_type_supported(unsigned long type)
-{
- /* TODO: Check if TDX is supported. */
- return __kvm_is_vm_type_supported(type);
-}
-
#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 346289a2a01c..f4da88a228d0 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -28,7 +28,6 @@ void vmx_hardware_unsetup(void);
int vmx_check_processor_compat(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);
@@ -137,8 +136,10 @@ 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 -EOPNOTSUPP; }
+static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
#endif

#endif /* __KVM_X86_VMX_X86_OPS_H */
--
2.25.1