[PATCH v5 20/23] KVM: nVMX: Add FRED VMCS fields to nested VMX context handling

["Xin Li (Intel)" <xin@zytor.com>]

From: Xin Li <xin3.li@intel.com>

Extend nested VMX context management to include FRED-related VMCS fields.
This enables proper handling of FRED state during nested virtualization.

Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
---

Change in v5:
* Add TB from Xuelian Guo.

Changes in v4:
* Advertise VMX nested exception as if the CPU supports it (Chao Gao).
* Split FRED state management controls (Chao Gao).

Changes in v3:
* Add and use nested_cpu_has_fred(vmcs12) because vmcs02 should be set
  from vmcs12 if and only if the field is enabled in L1's VMX config
  (Sean Christopherson).
* Fix coding style issues (Sean Christopherson).

Changes in v2:
* Remove hyperv TLFS related changes (Jeremi Piotrowski).
* Use kvm_cpu_cap_has() instead of cpu_feature_enabled() (Chao Gao).
---
 Documentation/virt/kvm/x86/nested-vmx.rst | 18 +++++
 arch/x86/kvm/vmx/capabilities.h           |  5 ++
 arch/x86/kvm/vmx/nested.c                 | 83 ++++++++++++++++++++++-
 arch/x86/kvm/vmx/nested.h                 | 22 ++++++
 arch/x86/kvm/vmx/vmcs12.c                 | 18 +++++
 arch/x86/kvm/vmx/vmcs12.h                 | 36 ++++++++++
 arch/x86/kvm/vmx/vmcs_shadow_fields.h     |  4 ++
 7 files changed, 184 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/x86/nested-vmx.rst b/Documentation/virt/kvm/x86/nested-vmx.rst
index e64ef231f310..87fa9f3877ab 100644
--- a/Documentation/virt/kvm/x86/nested-vmx.rst
+++ b/Documentation/virt/kvm/x86/nested-vmx.rst
@@ -218,6 +218,24 @@ struct shadow_vmcs is ever changed.
 		u16 host_gs_selector;
 		u16 host_tr_selector;
 		u64 secondary_vm_exit_controls;
+		u64 guest_ia32_fred_config;
+		u64 guest_ia32_fred_rsp1;
+		u64 guest_ia32_fred_rsp2;
+		u64 guest_ia32_fred_rsp3;
+		u64 guest_ia32_fred_stklvls;
+		u64 guest_ia32_fred_ssp1;
+		u64 guest_ia32_fred_ssp2;
+		u64 guest_ia32_fred_ssp3;
+		u64 host_ia32_fred_config;
+		u64 host_ia32_fred_rsp1;
+		u64 host_ia32_fred_rsp2;
+		u64 host_ia32_fred_rsp3;
+		u64 host_ia32_fred_stklvls;
+		u64 host_ia32_fred_ssp1;
+		u64 host_ia32_fred_ssp2;
+		u64 host_ia32_fred_ssp3;
+		u64 injected_event_data;
+		u64 original_event_data;
 	};
 
 
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 6d446574d770..cf7c93c33a98 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -78,6 +78,11 @@ static inline bool cpu_has_vmx_basic_inout(void)
 	return	vmcs_config.basic & VMX_BASIC_INOUT;
 }
 
+static inline bool cpu_has_vmx_nested_exception(void)
+{
+	return	vmcs_config.basic & VMX_BASIC_NESTED_EXCEPTION;
+}
+
 static inline bool cpu_has_virtual_nmis(void)
 {
 	return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS &&
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4405d176cf74..30d2de1243ef 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -705,6 +705,12 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
 
 	nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
 					 MSR_KERNEL_GS_BASE, MSR_TYPE_RW);
+
+	nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
+					 MSR_IA32_FRED_RSP0, MSR_TYPE_RW);
+
+	nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
+					 MSR_IA32_FRED_SSP0, MSR_TYPE_RW);
 #endif
 	nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
 					 MSR_IA32_SPEC_CTRL, MSR_TYPE_RW);
@@ -1272,9 +1278,11 @@ static int vmx_restore_vmx_basic(struct vcpu_vmx *vmx, u64 data)
 {
 	const u64 feature_bits = VMX_BASIC_DUAL_MONITOR_TREATMENT |
 				 VMX_BASIC_INOUT |
-				 VMX_BASIC_TRUE_CTLS;
+				 VMX_BASIC_TRUE_CTLS |
+				 VMX_BASIC_NESTED_EXCEPTION;
 
-	const u64 reserved_bits = GENMASK_ULL(63, 56) |
+	const u64 reserved_bits = GENMASK_ULL(63, 59) |
+				  GENMASK_ULL(57, 56) |
 				  GENMASK_ULL(47, 45) |
 				  BIT_ULL(31);
 
@@ -2526,6 +2534,8 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
 			     vmcs12->vm_entry_instruction_len);
 		vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
 			     vmcs12->guest_interruptibility_info);
+		if (cpu_has_vmx_fred())
+			vmcs_write64(INJECTED_EVENT_DATA, vmcs12->injected_event_data);
 		vmx->loaded_vmcs->nmi_known_unmasked =
 			!(vmcs12->guest_interruptibility_info & GUEST_INTR_STATE_NMI);
 	} else {
@@ -2578,6 +2588,17 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 		vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
 
 		vmx_segment_cache_clear(vmx);
+
+		if (nested_cpu_load_guest_fred_states(vmcs12)) {
+			vmcs_write64(GUEST_IA32_FRED_CONFIG, vmcs12->guest_ia32_fred_config);
+			vmcs_write64(GUEST_IA32_FRED_RSP1, vmcs12->guest_ia32_fred_rsp1);
+			vmcs_write64(GUEST_IA32_FRED_RSP2, vmcs12->guest_ia32_fred_rsp2);
+			vmcs_write64(GUEST_IA32_FRED_RSP3, vmcs12->guest_ia32_fred_rsp3);
+			vmcs_write64(GUEST_IA32_FRED_STKLVLS, vmcs12->guest_ia32_fred_stklvls);
+			vmcs_write64(GUEST_IA32_FRED_SSP1, vmcs12->guest_ia32_fred_ssp1);
+			vmcs_write64(GUEST_IA32_FRED_SSP2, vmcs12->guest_ia32_fred_ssp2);
+			vmcs_write64(GUEST_IA32_FRED_SSP3, vmcs12->guest_ia32_fred_ssp3);
+		}
 	}
 
 	if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
@@ -3864,6 +3885,8 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
 	u32 idt_vectoring;
 	unsigned int nr;
 
+	vmcs12->original_event_data = 0;
+
 	/*
 	 * Per the SDM, VM-Exits due to double and triple faults are never
 	 * considered to occur during event delivery, even if the double/triple
@@ -3902,6 +3925,13 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
 				vcpu->arch.exception.error_code;
 		}
 
+		if ((vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) &&
+		    (vmcs12->guest_cr4 & X86_CR4_FRED) &&
+		    (vcpu->arch.exception.nested))
+			idt_vectoring |= VECTORING_INFO_NESTED_EXCEPTION_MASK;
+
+		vmcs12->original_event_data = vcpu->arch.exception.event_data;
+
 		vmcs12->idt_vectoring_info_field = idt_vectoring;
 	} else if (vcpu->arch.nmi_injected) {
 		vmcs12->idt_vectoring_info_field =
@@ -4482,6 +4512,14 @@ static bool is_vmcs12_ext_field(unsigned long field)
 	case GUEST_TR_BASE:
 	case GUEST_GDTR_BASE:
 	case GUEST_IDTR_BASE:
+	case GUEST_IA32_FRED_CONFIG:
+	case GUEST_IA32_FRED_RSP1:
+	case GUEST_IA32_FRED_RSP2:
+	case GUEST_IA32_FRED_RSP3:
+	case GUEST_IA32_FRED_STKLVLS:
+	case GUEST_IA32_FRED_SSP1:
+	case GUEST_IA32_FRED_SSP2:
+	case GUEST_IA32_FRED_SSP3:
 	case GUEST_PENDING_DBG_EXCEPTIONS:
 	case GUEST_BNDCFGS:
 		return true;
@@ -4531,6 +4569,18 @@ static void sync_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu,
 	vmcs12->guest_tr_base = vmcs_readl(GUEST_TR_BASE);
 	vmcs12->guest_gdtr_base = vmcs_readl(GUEST_GDTR_BASE);
 	vmcs12->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE);
+
+	if (nested_cpu_save_guest_fred_states(vmcs12)) {
+		vmcs12->guest_ia32_fred_config = vmcs_read64(GUEST_IA32_FRED_CONFIG);
+		vmcs12->guest_ia32_fred_rsp1 = vmcs_read64(GUEST_IA32_FRED_RSP1);
+		vmcs12->guest_ia32_fred_rsp2 = vmcs_read64(GUEST_IA32_FRED_RSP2);
+		vmcs12->guest_ia32_fred_rsp3 = vmcs_read64(GUEST_IA32_FRED_RSP3);
+		vmcs12->guest_ia32_fred_stklvls = vmcs_read64(GUEST_IA32_FRED_STKLVLS);
+		vmcs12->guest_ia32_fred_ssp1 = vmcs_read64(GUEST_IA32_FRED_SSP1);
+		vmcs12->guest_ia32_fred_ssp2 = vmcs_read64(GUEST_IA32_FRED_SSP2);
+		vmcs12->guest_ia32_fred_ssp3 = vmcs_read64(GUEST_IA32_FRED_SSP3);
+	}
+
 	vmcs12->guest_pending_dbg_exceptions =
 		vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS);
 
@@ -4684,6 +4734,21 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 
 		vmcs12->vm_exit_intr_info = exit_intr_info;
 		vmcs12->vm_exit_instruction_len = exit_insn_len;
+
+		/*
+		 * When there is a valid original event, the exiting event is a nested
+		 * event during delivery of the earlier original event.
+		 *
+		 * FRED event delivery reflects this relationship by setting the value
+		 * of the nested exception bit of VM-exit interruption information
+		 * (aka exiting-event identification) to that of the valid bit of the
+		 * IDT-vectoring information (aka original-event identification).
+		 */
+		if ((vmcs12->idt_vectoring_info_field & VECTORING_INFO_VALID_MASK) &&
+		    (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) &&
+		    (vmcs12->guest_cr4 & X86_CR4_FRED))
+			vmcs12->vm_exit_intr_info |= INTR_INFO_NESTED_EXCEPTION_MASK;
+
 		vmcs12->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
 
 		/*
@@ -4761,6 +4826,17 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
 	vmcs_write32(GUEST_IDTR_LIMIT, 0xFFFF);
 	vmcs_write32(GUEST_GDTR_LIMIT, 0xFFFF);
 
+	if (nested_cpu_load_host_fred_states(vmcs12)) {
+		vmcs_write64(GUEST_IA32_FRED_CONFIG, vmcs12->host_ia32_fred_config);
+		vmcs_write64(GUEST_IA32_FRED_RSP1, vmcs12->host_ia32_fred_rsp1);
+		vmcs_write64(GUEST_IA32_FRED_RSP2, vmcs12->host_ia32_fred_rsp2);
+		vmcs_write64(GUEST_IA32_FRED_RSP3, vmcs12->host_ia32_fred_rsp3);
+		vmcs_write64(GUEST_IA32_FRED_STKLVLS, vmcs12->host_ia32_fred_stklvls);
+		vmcs_write64(GUEST_IA32_FRED_SSP1, vmcs12->host_ia32_fred_ssp1);
+		vmcs_write64(GUEST_IA32_FRED_SSP2, vmcs12->host_ia32_fred_ssp2);
+		vmcs_write64(GUEST_IA32_FRED_SSP3, vmcs12->host_ia32_fred_ssp3);
+	}
+
 	/* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1.  */
 	if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
 		vmcs_write64(GUEST_BNDCFGS, 0);
@@ -7228,6 +7304,9 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)
 	msrs->basic |= VMX_BASIC_TRUE_CTLS;
 	if (cpu_has_vmx_basic_inout())
 		msrs->basic |= VMX_BASIC_INOUT;
+
+	if (cpu_has_vmx_nested_exception())
+		msrs->basic |= VMX_BASIC_NESTED_EXCEPTION;
 }
 
 static void nested_vmx_setup_cr_fixed(struct nested_vmx_msrs *msrs)
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 6eedcfc91070..c6b69699e28e 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -249,6 +249,11 @@ static inline bool nested_cpu_has_save_preemption_timer(struct vmcs12 *vmcs12)
 	    VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
 }
 
+static inline bool nested_cpu_has_secondary_vm_exit_controls(struct vmcs12 *vmcs12)
+{
+	return vmcs12->vm_exit_controls & VM_EXIT_ACTIVATE_SECONDARY_CONTROLS;
+}
+
 static inline bool nested_exit_on_nmi(struct kvm_vcpu *vcpu)
 {
 	return nested_cpu_has_nmi_exiting(get_vmcs12(vcpu));
@@ -269,6 +274,23 @@ static inline bool nested_cpu_has_encls_exit(struct vmcs12 *vmcs12)
 	return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENCLS_EXITING);
 }
 
+static inline bool nested_cpu_load_guest_fred_states(struct vmcs12 *vmcs12)
+{
+	return vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_FRED;
+}
+
+static inline bool nested_cpu_save_guest_fred_states(struct vmcs12 *vmcs12)
+{
+	return nested_cpu_has_secondary_vm_exit_controls(vmcs12) &&
+	       vmcs12->secondary_vm_exit_controls & SECONDARY_VM_EXIT_SAVE_IA32_FRED;
+}
+
+static inline bool nested_cpu_load_host_fred_states(struct vmcs12 *vmcs12)
+{
+	return nested_cpu_has_secondary_vm_exit_controls(vmcs12) &&
+	       vmcs12->secondary_vm_exit_controls & SECONDARY_VM_EXIT_LOAD_IA32_FRED;
+}
+
 /*
  * if fixed0[i] == 1: val[i] must be 1
  * if fixed1[i] == 0: val[i] must be 0
diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c
index 9fac24fd5b4b..5fa63326deba 100644
--- a/arch/x86/kvm/vmx/vmcs12.c
+++ b/arch/x86/kvm/vmx/vmcs12.c
@@ -67,6 +67,24 @@ const unsigned short vmcs12_field_offsets[] = {
 	FIELD64(HOST_IA32_EFER, host_ia32_efer),
 	FIELD64(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl),
 	FIELD64(SECONDARY_VM_EXIT_CONTROLS, secondary_vm_exit_controls),
+	FIELD64(INJECTED_EVENT_DATA, injected_event_data),
+	FIELD64(ORIGINAL_EVENT_DATA, original_event_data),
+	FIELD64(GUEST_IA32_FRED_CONFIG, guest_ia32_fred_config),
+	FIELD64(GUEST_IA32_FRED_RSP1, guest_ia32_fred_rsp1),
+	FIELD64(GUEST_IA32_FRED_RSP2, guest_ia32_fred_rsp2),
+	FIELD64(GUEST_IA32_FRED_RSP3, guest_ia32_fred_rsp3),
+	FIELD64(GUEST_IA32_FRED_STKLVLS, guest_ia32_fred_stklvls),
+	FIELD64(GUEST_IA32_FRED_SSP1, guest_ia32_fred_ssp1),
+	FIELD64(GUEST_IA32_FRED_SSP2, guest_ia32_fred_ssp2),
+	FIELD64(GUEST_IA32_FRED_SSP3, guest_ia32_fred_ssp3),
+	FIELD64(HOST_IA32_FRED_CONFIG, host_ia32_fred_config),
+	FIELD64(HOST_IA32_FRED_RSP1, host_ia32_fred_rsp1),
+	FIELD64(HOST_IA32_FRED_RSP2, host_ia32_fred_rsp2),
+	FIELD64(HOST_IA32_FRED_RSP3, host_ia32_fred_rsp3),
+	FIELD64(HOST_IA32_FRED_STKLVLS, host_ia32_fred_stklvls),
+	FIELD64(HOST_IA32_FRED_SSP1, host_ia32_fred_ssp1),
+	FIELD64(HOST_IA32_FRED_SSP2, host_ia32_fred_ssp2),
+	FIELD64(HOST_IA32_FRED_SSP3, host_ia32_fred_ssp3),
 	FIELD(PIN_BASED_VM_EXEC_CONTROL, pin_based_vm_exec_control),
 	FIELD(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control),
 	FIELD(EXCEPTION_BITMAP, exception_bitmap),
diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h
index 1fe3ed9108aa..f2a33d7007c9 100644
--- a/arch/x86/kvm/vmx/vmcs12.h
+++ b/arch/x86/kvm/vmx/vmcs12.h
@@ -186,6 +186,24 @@ struct __packed vmcs12 {
 	u16 host_tr_selector;
 	u16 guest_pml_index;
 	u64 secondary_vm_exit_controls;
+	u64 guest_ia32_fred_config;
+	u64 guest_ia32_fred_rsp1;
+	u64 guest_ia32_fred_rsp2;
+	u64 guest_ia32_fred_rsp3;
+	u64 guest_ia32_fred_stklvls;
+	u64 guest_ia32_fred_ssp1;
+	u64 guest_ia32_fred_ssp2;
+	u64 guest_ia32_fred_ssp3;
+	u64 host_ia32_fred_config;
+	u64 host_ia32_fred_rsp1;
+	u64 host_ia32_fred_rsp2;
+	u64 host_ia32_fred_rsp3;
+	u64 host_ia32_fred_stklvls;
+	u64 host_ia32_fred_ssp1;
+	u64 host_ia32_fred_ssp2;
+	u64 host_ia32_fred_ssp3;
+	u64 injected_event_data;
+	u64 original_event_data;
 };
 
 /*
@@ -362,6 +380,24 @@ static inline void vmx_check_vmcs12_offsets(void)
 	CHECK_OFFSET(host_tr_selector, 994);
 	CHECK_OFFSET(guest_pml_index, 996);
 	CHECK_OFFSET(secondary_vm_exit_controls, 998);
+	CHECK_OFFSET(guest_ia32_fred_config, 1006);
+	CHECK_OFFSET(guest_ia32_fred_rsp1, 1014);
+	CHECK_OFFSET(guest_ia32_fred_rsp2, 1022);
+	CHECK_OFFSET(guest_ia32_fred_rsp3, 1030);
+	CHECK_OFFSET(guest_ia32_fred_stklvls, 1038);
+	CHECK_OFFSET(guest_ia32_fred_ssp1, 1046);
+	CHECK_OFFSET(guest_ia32_fred_ssp2, 1054);
+	CHECK_OFFSET(guest_ia32_fred_ssp3, 1062);
+	CHECK_OFFSET(host_ia32_fred_config, 1070);
+	CHECK_OFFSET(host_ia32_fred_rsp1, 1078);
+	CHECK_OFFSET(host_ia32_fred_rsp2, 1086);
+	CHECK_OFFSET(host_ia32_fred_rsp3, 1094);
+	CHECK_OFFSET(host_ia32_fred_stklvls, 1102);
+	CHECK_OFFSET(host_ia32_fred_ssp1, 1110);
+	CHECK_OFFSET(host_ia32_fred_ssp2, 1118);
+	CHECK_OFFSET(host_ia32_fred_ssp3, 1126);
+	CHECK_OFFSET(injected_event_data, 1134);
+	CHECK_OFFSET(original_event_data, 1142);
 }
 
 extern const unsigned short vmcs12_field_offsets[];
diff --git a/arch/x86/kvm/vmx/vmcs_shadow_fields.h b/arch/x86/kvm/vmx/vmcs_shadow_fields.h
index cad128d1657b..da338327c2b3 100644
--- a/arch/x86/kvm/vmx/vmcs_shadow_fields.h
+++ b/arch/x86/kvm/vmx/vmcs_shadow_fields.h
@@ -74,6 +74,10 @@ SHADOW_FIELD_RW(HOST_GS_BASE, host_gs_base)
 /* 64-bit */
 SHADOW_FIELD_RO(GUEST_PHYSICAL_ADDRESS, guest_physical_address)
 SHADOW_FIELD_RO(GUEST_PHYSICAL_ADDRESS_HIGH, guest_physical_address)
+SHADOW_FIELD_RO(ORIGINAL_EVENT_DATA, original_event_data)
+SHADOW_FIELD_RO(ORIGINAL_EVENT_DATA_HIGH, original_event_data)
+SHADOW_FIELD_RW(INJECTED_EVENT_DATA, injected_event_data)
+SHADOW_FIELD_RW(INJECTED_EVENT_DATA_HIGH, injected_event_data)
 
 #undef SHADOW_FIELD_RO
 #undef SHADOW_FIELD_RW
-- 
2.50.1