[PATCH v19 125/130] KVM: TDX: Add methods to ignore virtual apic related operation

isaku.yamahata
2024-02-26T08:29:19Z

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

TDX protects TDX guest APIC state from VMM. Implement access methods of
TDX guest vAPIC state to ignore them or return zero.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/vmx/main.c | 61 ++++++++++++++++++++++++++++++++++----
arch/x86/kvm/vmx/tdx.c | 6 ++++
arch/x86/kvm/vmx/x86_ops.h | 3 ++
3 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index fae5a3668361..c46c860be0f2 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -352,6 +352,14 @@ static bool vt_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
return vmx_apic_init_signal_blocked(vcpu);
}

+static void vt_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
+{
+ if (is_td_vcpu(vcpu))
+ return tdx_set_virtual_apic_mode(vcpu);
+
+ return vmx_set_virtual_apic_mode(vcpu);
+}
+
static void vt_apicv_pre_state_restore(struct kvm_vcpu *vcpu)
{
struct pi_desc *pi = vcpu_to_pi_desc(vcpu);
@@ -360,6 +368,31 @@ static void vt_apicv_pre_state_restore(struct kvm_vcpu *vcpu)
memset(pi->pir, 0, sizeof(pi->pir));
}

+static void vt_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
+{
+ if (is_td_vcpu(vcpu))
+ return;
+
+ return vmx_hwapic_irr_update(vcpu, max_irr);
+}
+
+static void vt_hwapic_isr_update(int max_isr)
+{
+ if (is_td_vcpu(kvm_get_running_vcpu()))
+ return;
+
+ return vmx_hwapic_isr_update(max_isr);
+}
+
+static bool vt_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
+{
+ /* TDX doesn't support L2 at the moment. */
+ if (WARN_ON_ONCE(is_td_vcpu(vcpu)))
+ return false;
+
+ return vmx_guest_apic_has_interrupt(vcpu);
+}
+
static int vt_sync_pir_to_irr(struct kvm_vcpu *vcpu)
{
if (is_td_vcpu(vcpu))
@@ -815,6 +848,22 @@ static void vt_update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
vmx_update_cr8_intercept(vcpu, tpr, irr);
}

+static void vt_set_apic_access_page_addr(struct kvm_vcpu *vcpu)
+{
+ if (is_td_vcpu(vcpu))
+ return;
+
+ vmx_set_apic_access_page_addr(vcpu);
+}
+
+static void vt_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
+{
+ if (WARN_ON_ONCE(is_td_vcpu(vcpu)))
+ return;
+
+ vmx_refresh_apicv_exec_ctrl(vcpu);
+}
+
static void vt_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
{
if (is_td_vcpu(vcpu))
@@ -1055,15 +1104,15 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
.enable_nmi_window = vt_enable_nmi_window,
.enable_irq_window = vt_enable_irq_window,
.update_cr8_intercept = vt_update_cr8_intercept,
- .set_virtual_apic_mode = vmx_set_virtual_apic_mode,
- .set_apic_access_page_addr = vmx_set_apic_access_page_addr,
- .refresh_apicv_exec_ctrl = vmx_refresh_apicv_exec_ctrl,
+ .set_virtual_apic_mode = vt_set_virtual_apic_mode,
+ .set_apic_access_page_addr = vt_set_apic_access_page_addr,
+ .refresh_apicv_exec_ctrl = vt_refresh_apicv_exec_ctrl,
.load_eoi_exitmap = vt_load_eoi_exitmap,
.apicv_pre_state_restore = vt_apicv_pre_state_restore,
.required_apicv_inhibits = VMX_REQUIRED_APICV_INHIBITS,
- .hwapic_irr_update = vmx_hwapic_irr_update,
- .hwapic_isr_update = vmx_hwapic_isr_update,
- .guest_apic_has_interrupt = vmx_guest_apic_has_interrupt,
+ .hwapic_irr_update = vt_hwapic_irr_update,
+ .hwapic_isr_update = vt_hwapic_isr_update,
+ .guest_apic_has_interrupt = vt_guest_apic_has_interrupt,
.sync_pir_to_irr = vt_sync_pir_to_irr,
.deliver_interrupt = vt_deliver_interrupt,
.dy_apicv_has_pending_interrupt = pi_has_pending_interrupt,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index fc78e9ca61c1..f706c346eea4 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -2080,6 +2080,12 @@ void tdx_enable_smi_window(struct kvm_vcpu *vcpu)
}
#endif

+void tdx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
+{
+ /* Only x2APIC mode is supported for TD. */
+ WARN_ON_ONCE(kvm_get_apic_mode(vcpu) != LAPIC_MODE_X2APIC);
+}
+
int tdx_get_cpl(struct kvm_vcpu *vcpu)
{
return 0;
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 727c4d418601..c507f1513dac 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -168,6 +168,7 @@ void tdx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
bool tdx_has_emulated_msr(u32 index, bool write);
int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
+void tdx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);

int tdx_get_cpl(struct kvm_vcpu *vcpu);
void tdx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg);
@@ -227,6 +228,8 @@ static inline bool tdx_has_emulated_msr(u32 index, bool write) { return false; }
static inline int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) { return 1; }
static inline int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) { return 1; }

+static inline void tdx_set_virtual_apic_mode(struct kvm_vcpu *vcpu) {}
+
static inline int tdx_get_cpl(struct kvm_vcpu *vcpu) { return 0; }
static inline void tdx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg) {}
static inline unsigned long tdx_get_rflags(struct kvm_vcpu *vcpu) { return 0; }
--
2.25.1