[PATCH v19 121/130] KVM: TDX: Add methods to ignore VMX preemption timer

isaku.yamahata
2024-02-26T08:29:15Z

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

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

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/vmx/main.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 991bfdecaed2..ec5c0fda92e9 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -842,6 +842,27 @@ 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))
@@ -1024,8 +1045,8 @@ 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,
--
2.25.1