[v18,110/121] KVM: TDX: Add methods to ignore VMX preemption timer

Commit Message

Isaku Yamahata Jan. 22, 2024, 11:54 p.m. UTC

From: Isaku Yamahata <[e-mail]>

TDX doesn't support VMX preemption timer.  Implement access methods for VMM
to ignore VMX preemption timer.

Signed-off-by: Isaku Yamahata <[e-mail]>
---
 arch/x86/kvm/vmx/main.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index c9f72c383eee..74e5197733ef 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -855,6 +855,27 @@  static void vt_update_cpu_dirty_logging(struct kvm_vcpu *vcpu)
 	vmx_update_cpu_dirty_logging(vcpu);
 }
 
+#ifdef CONFIG_X86_64
+static int vt_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
+			      bool *expired)
+{
+	/* VMX-preemption timer isn't available for TDX. */
+	if (is_td_vcpu(vcpu))
+		return -EINVAL;
+
+	return vmx_set_hv_timer(vcpu, guest_deadline_tsc, expired);
+}
+
+static void vt_cancel_hv_timer(struct kvm_vcpu *vcpu)
+{
+	/* VMX-preemption timer can't be set.  See vt_set_hv_timer(). */
+	if (KVM_BUG_ON(is_td_vcpu(vcpu), vcpu->kvm))
+		return;
+
+	vmx_cancel_hv_timer(vcpu);
+}
+#endif
+
 static int vt_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
 {
 	if (!is_td(kvm))
@@ -1006,8 +1027,8 @@  struct kvm_x86_ops vt_x86_ops __initdata = {
 	.pi_start_assignment = vmx_pi_start_assignment,
 
 #ifdef CONFIG_X86_64
-	.set_hv_timer = vmx_set_hv_timer,
-	.cancel_hv_timer = vmx_cancel_hv_timer,
+	.set_hv_timer = vt_set_hv_timer,
+	.cancel_hv_timer = vt_cancel_hv_timer,
 #endif
 
 	.setup_mce = vmx_setup_mce,