[PATCH v11 102/113] KVM: TDX: Silently ignore INIT/SIPI

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

The TDX module API doesn't provide API for VMM to inject INIT IPI and SIPI.
Instead it defines the different protocols to boot application processors.
Ignore INIT and SIPI events for the TDX guest.

There are two options. 1) (silently) ignore INIT/SIPI request or 2) return
error to guest TDs somehow.  Given that TDX guest is paravirtualized to
boot AP, the option 1 is chosen for simplicity.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/include/asm/kvm-x86-ops.h |  1 +
 arch/x86/include/asm/kvm_host.h    |  2 ++
 arch/x86/kvm/lapic.c               | 19 +++++++++++-------
 arch/x86/kvm/svm/svm.c             |  1 +
 arch/x86/kvm/vmx/main.c            | 32 ++++++++++++++++++++++++++++--
 5 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index aeff96543090..0cf928d12067 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -143,6 +143,7 @@ KVM_X86_OP_OPTIONAL(migrate_timers)
 KVM_X86_OP(msr_filter_changed)
 KVM_X86_OP(complete_emulated_msr)
 KVM_X86_OP(vcpu_deliver_sipi_vector)
+KVM_X86_OP(vcpu_deliver_init)
 KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons);
 
 #undef KVM_X86_OP
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f93d271aba67..75e53b2bb4af 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1775,6 +1775,7 @@ struct kvm_x86_ops {
 	int (*complete_emulated_msr)(struct kvm_vcpu *vcpu, int err);
 
 	void (*vcpu_deliver_sipi_vector)(struct kvm_vcpu *vcpu, u8 vector);
+	void (*vcpu_deliver_init)(struct kvm_vcpu *vcpu);
 
 	/*
 	 * Returns vCPU specific APICv inhibit reasons
@@ -1986,6 +1987,7 @@ void kvm_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg);
 void kvm_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg);
 int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int seg);
 void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
+void kvm_vcpu_deliver_init(struct kvm_vcpu *vcpu);
 
 int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
 		    int reason, bool has_error_code, u32 error_code);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 9e5ffe355847..68a683fe8a2f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -3032,6 +3032,16 @@ int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len)
 	return 0;
 }
 
+void kvm_vcpu_deliver_init(struct kvm_vcpu *vcpu)
+{
+	kvm_vcpu_reset(vcpu, true);
+	if (kvm_vcpu_is_bsp(vcpu))
+		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+	else
+		vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_deliver_init);
+
 int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
@@ -3063,13 +3073,8 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
 		return 0;
 	}
 
-	if (test_and_clear_bit(KVM_APIC_INIT, &apic->pending_events)) {
-		kvm_vcpu_reset(vcpu, true);
-		if (kvm_vcpu_is_bsp(apic->vcpu))
-			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
-		else
-			vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
-	}
+	if (test_and_clear_bit(KVM_APIC_INIT, &apic->pending_events))
+		static_call(kvm_x86_vcpu_deliver_init)(vcpu);
 	if (test_and_clear_bit(KVM_APIC_SIPI, &apic->pending_events)) {
 		if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
 			/* evaluate pending_events before reading the vector */
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 55f2e0a9b0f6..f9191d924212 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4829,6 +4829,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.complete_emulated_msr = svm_complete_emulated_msr,
 
 	.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
+	.vcpu_deliver_init = kvm_vcpu_deliver_init,
 	.vcpu_get_apicv_inhibit_reasons = avic_vcpu_get_apicv_inhibit_reasons,
 };
 
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 3651c32e6cad..4be7b27bf579 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -256,6 +256,14 @@ static void vt_enable_smi_window(struct kvm_vcpu *vcpu)
 }
 #endif
 
+static bool vt_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu))
+		return true;
+
+	return vmx_apic_init_signal_blocked(vcpu);
+}
+
 static void vt_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 {
 	struct pi_desc *pi = vcpu_to_pi_desc(vcpu);
@@ -284,6 +292,25 @@ static void vt_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
 	vmx_deliver_interrupt(apic, delivery_mode, trig_mode, vector);
 }
 
+static void vt_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
+{
+	if (is_td_vcpu(vcpu))
+		return;
+
+	kvm_vcpu_deliver_sipi_vector(vcpu, vector);
+}
+
+static void vt_vcpu_deliver_init(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu)) {
+		/* TDX doesn't support INIT.  Ignore INIT event */
+		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+		return;
+	}
+
+	kvm_vcpu_deliver_init(vcpu);
+}
+
 static void vt_flush_tlb_all(struct kvm_vcpu *vcpu)
 {
 	if (is_td_vcpu(vcpu))
@@ -630,13 +657,14 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 #endif
 
 	.can_emulate_instruction = vmx_can_emulate_instruction,
-	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
+	.apic_init_signal_blocked = vt_apic_init_signal_blocked,
 	.migrate_timers = vmx_migrate_timers,
 
 	.msr_filter_changed = vt_msr_filter_changed,
 	.complete_emulated_msr = kvm_complete_insn_gp,
 
-	.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,
+	.vcpu_deliver_sipi_vector = vt_vcpu_deliver_sipi_vector,
+	.vcpu_deliver_init = vt_vcpu_deliver_init,
 
 	.dev_mem_enc_ioctl = tdx_dev_ioctl,
 	.mem_enc_ioctl = vt_mem_enc_ioctl,
-- 
2.25.1