Received-SPF: pass (google.com: domain of linux-kernel+bounces-80884-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: isaku.yamahata@intel.com
To: kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: isaku.yamahata@intel.com,
	isaku.yamahata@gmail.com,
	Paolo Bonzini <pbonzini@redhat.com>,
	erdemaktas@google.com,
	Sean Christopherson <seanjc@google.com>,
	Sagi Shahar <sagis@google.com>,
	Kai Huang <kai.huang@intel.com>,
	chen.bo@intel.com,
	hang.yuan@intel.com,
	tina.zhang@intel.com
Subject: [PATCH v19 121/130] KVM: TDX: Add methods to ignore VMX preemption timer
Date: Mon, 26 Feb 2024 00:27:03 -0800
Message-Id: <30cd8696d4c6ab2e909b9ded93049ab217c713f8.1708933498.git.isaku.yamahata@intel.com>
In-Reply-To: <cover.1708933498.git.isaku.yamahata@intel.com>
References: <cover.1708933498.git.isaku.yamahata@intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

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