[PATCH v18 115/121] KVM: TDX: Inhibit APICv for TDX guest

[isaku.yamahata@intel.com]

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

TDX doesn't support APICV, inhibit APICv for TDX guest.  Follow how SEV
does it.  Define a new inhibit reason for TDX, set it on TD
initialization, and add the flag to kvm_x86_ops.required_apicv_inhibits.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/include/asm/kvm_host.h | 9 +++++++++
 arch/x86/kvm/vmx/main.c         | 3 ++-
 arch/x86/kvm/vmx/tdx.c          | 4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 59a1c55c48f0..54ac65b75f18 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1314,6 +1314,15 @@ enum kvm_apicv_inhibit {
 	 * mapping between logical ID and vCPU.
 	 */
 	APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED,
+
+	/*********************************************************/
+	/* INHIBITs that are relevant only to the Intel's APICv. */
+	/*********************************************************/
+
+	/*
+	 * APICv is disabled because TDX doesn't support it.
+	 */
+	APICV_INHIBIT_REASON_TDX,
 };
 
 struct kvm_arch {
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 48d71c2cef1b..dd2859328593 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -1005,7 +1005,8 @@ static int vt_vcpu_mem_enc_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 	 BIT(APICV_INHIBIT_REASON_BLOCKIRQ) |			\
 	 BIT(APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED) |	\
 	 BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) |		\
-	 BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED))
+	 BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED) |		\
+	 BIT(APICV_INHIBIT_REASON_TDX))
 
 struct kvm_x86_ops vt_x86_ops __initdata = {
 	.name = KBUILD_MODNAME,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index a879a7fb0f03..be1cc08dd74a 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -2533,6 +2533,8 @@ static int __tdx_td_init(struct kvm *kvm, struct td_params *td_params,
 		goto teardown;
 	}
 
+	kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_TDX);
+
 	return 0;
 
 	/*
@@ -2895,6 +2897,8 @@ static int tdx_td_vcpu_init(struct kvm_vcpu *vcpu, u64 vcpu_rcx)
 		return -EIO;
 	}
 
+	WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm));
+	vcpu->arch.apic->apicv_active = false;
 	vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 	tdx->td_vcpu_created = true;
 	return 0;
-- 
2.25.1