Merge tag 'kvm-x86-vmx-6.11' of https://github.com/kvm-x86/linux into HEAD

KVM VMX changes for 6.11

 - Remove an unnecessary EPT TLB flush when enabling hardware.

 - Fix a series of bugs that cause KVM to fail to detect nested pending posted
   interrupts as valid wake eents for a vCPU executing HLT in L2 (with
   HLT-exiting disable by L1).

 - Misc cleanups

Author: bonzini

arch/x86/include/asm/kvm-x86-ops.h

@@ -85,7 +85,6 @@ KVM_X86_OP_OPTIONAL(update_cr8_intercept)
 KVM_X86_OP(refresh_apicv_exec_ctrl)
 KVM_X86_OP_OPTIONAL(hwapic_irr_update)
 KVM_X86_OP_OPTIONAL(hwapic_isr_update)
-KVM_X86_OP_OPTIONAL_RET0(guest_apic_has_interrupt)
 KVM_X86_OP_OPTIONAL(load_eoi_exitmap)
 KVM_X86_OP_OPTIONAL(set_virtual_apic_mode)
 KVM_X86_OP_OPTIONAL(set_apic_access_page_addr)

arch/x86/include/asm/kvm_host.h

@@ -1731,7 +1731,6 @@ struct kvm_x86_ops {
 	void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu);
 	void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
 	void (*hwapic_isr_update)(int isr);
-	bool (*guest_apic_has_interrupt)(struct kvm_vcpu *vcpu);
 	void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
 	void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu);
 	void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu);
@@ -1837,7 +1836,7 @@ struct kvm_x86_nested_ops {
 	bool (*is_exception_vmexit)(struct kvm_vcpu *vcpu, u8 vector,
 				    u32 error_code);
 	int (*check_events)(struct kvm_vcpu *vcpu);
-	bool (*has_events)(struct kvm_vcpu *vcpu);
+	bool (*has_events)(struct kvm_vcpu *vcpu, bool for_injection);
 	void (*triple_fault)(struct kvm_vcpu *vcpu);
 	int (*get_state)(struct kvm_vcpu *vcpu,
 			 struct kvm_nested_state __user *user_kvm_nested_state,

arch/x86/kvm/vmx/main.c

@@ -97,7 +97,6 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.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,
 	.sync_pir_to_irr = vmx_sync_pir_to_irr,
 	.deliver_interrupt = vmx_deliver_interrupt,
 	.dy_apicv_has_pending_interrupt = pi_has_pending_interrupt,

arch/x86/kvm/vmx/nested.c

@@ -12,6 +12,7 @@
 #include "mmu.h"
 #include "nested.h"
 #include "pmu.h"
+#include "posted_intr.h"
 #include "sgx.h"
 #include "trace.h"
 #include "vmx.h"
@@ -3899,8 +3900,8 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
 	if (!pi_test_and_clear_on(vmx->nested.pi_desc))
 		return 0;
 
-	max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256);
-	if (max_irr != 256) {
+	max_irr = pi_find_highest_vector(vmx->nested.pi_desc);
+	if (max_irr > 0) {
 		vapic_page = vmx->nested.virtual_apic_map.hva;
 		if (!vapic_page)
 			goto mmio_needed;
@@ -4031,10 +4032,46 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu)
 	       to_vmx(vcpu)->nested.preemption_timer_expired;
 }
 
-static bool vmx_has_nested_events(struct kvm_vcpu *vcpu)
+static bool vmx_has_nested_events(struct kvm_vcpu *vcpu, bool for_injection)
 {
-	return nested_vmx_preemption_timer_pending(vcpu) ||
-	       to_vmx(vcpu)->nested.mtf_pending;
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	void *vapic = vmx->nested.virtual_apic_map.hva;
+	int max_irr, vppr;
+
+	if (nested_vmx_preemption_timer_pending(vcpu) ||
+	    vmx->nested.mtf_pending)
+		return true;
+
+	/*
+	 * Virtual Interrupt Delivery doesn't require manual injection.  Either
+	 * the interrupt is already in GUEST_RVI and will be recognized by CPU
+	 * at VM-Entry, or there is a KVM_REQ_EVENT pending and KVM will move
+	 * the interrupt from the PIR to RVI prior to entering the guest.
+	 */
+	if (for_injection)
+		return false;
+
+	if (!nested_cpu_has_vid(get_vmcs12(vcpu)) ||
+	    __vmx_interrupt_blocked(vcpu))
+		return false;
+
+	if (!vapic)
+		return false;
+
+	vppr = *((u32 *)(vapic + APIC_PROCPRI));
+
+	max_irr = vmx_get_rvi();
+	if ((max_irr & 0xf0) > (vppr & 0xf0))
+		return true;
+
+	if (vmx->nested.pi_pending && vmx->nested.pi_desc &&
+	    pi_test_on(vmx->nested.pi_desc)) {
+		max_irr = pi_find_highest_vector(vmx->nested.pi_desc);
+		if (max_irr > 0 && (max_irr & 0xf0) > (vppr & 0xf0))
+			return true;
+	}
+
+	return false;
 }
 
 /*

arch/x86/kvm/vmx/posted_intr.h

@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __KVM_X86_VMX_POSTED_INTR_H
 #define __KVM_X86_VMX_POSTED_INTR_H
+
+#include <linux/find.h>
 #include <asm/posted_intr.h>
 
 void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu);
@@ -12,4 +14,12 @@ int vmx_pi_update_irte(struct kvm *kvm, unsigned int host_irq,
 		       uint32_t guest_irq, bool set);
 void vmx_pi_start_assignment(struct kvm *kvm);
 
+static inline int pi_find_highest_vector(struct pi_desc *pi_desc)
+{
+	int vec;
+
+	vec = find_last_bit((unsigned long *)pi_desc->pir, 256);
+	return vec < 256 ? vec : -1;
+}
+
 #endif /* __KVM_X86_VMX_POSTED_INTR_H */

arch/x86/kvm/vmx/vmcs12.h

@@ -188,12 +188,13 @@ struct __packed vmcs12 {
 };
 
 /*
- * VMCS12_REVISION is an arbitrary id that should be changed if the content or
- * layout of struct vmcs12 is changed. MSR_IA32_VMX_BASIC returns this id, and
- * VMPTRLD verifies that the VMCS region that L1 is loading contains this id.
+ * VMCS12_REVISION is KVM's arbitrary ID for the layout of struct vmcs12.  KVM
+ * enumerates this value to L1 via MSR_IA32_VMX_BASIC, and checks the revision
+ * ID during nested VMPTRLD to verify that L1 is loading a VMCS that adhere's
+ * to KVM's virtual CPU definition.
  *
- * IMPORTANT: Changing this value will break save/restore compatibility with
- * older kvm releases.
+ * DO NOT change this value, as it will break save/restore compatibility with
+ * older KVM releases.
  */
 #define VMCS12_REVISION 0x11e57ed0
 
@@ -206,7 +207,8 @@ struct __packed vmcs12 {
 #define VMCS12_SIZE		KVM_STATE_NESTED_VMX_VMCS_SIZE
 
 /*
- * For save/restore compatibility, the vmcs12 field offsets must not change.
+ * For save/restore compatibility, the vmcs12 field offsets must not change,
+ * although appending fields and/or filling gaps is obviously allowed.
  */
 #define CHECK_OFFSET(field, loc) \
 	ASSERT_STRUCT_OFFSET(struct vmcs12, field, loc)

arch/x86/kvm/vmx/vmx.c

@@ -2868,9 +2868,6 @@ int vmx_hardware_enable(void)
 		return r;
 	}
 
-	if (enable_ept)
-		ept_sync_global();
-
 	return 0;
 }
 
@@ -4142,26 +4139,6 @@ void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu)
 	}
 }
 
-bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
-{
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	void *vapic_page;
-	u32 vppr;
-	int rvi;
-
-	if (WARN_ON_ONCE(!is_guest_mode(vcpu)) ||
-		!nested_cpu_has_vid(get_vmcs12(vcpu)) ||
-		WARN_ON_ONCE(!vmx->nested.virtual_apic_map.gfn))
-		return false;
-
-	rvi = vmx_get_rvi();
-
-	vapic_page = vmx->nested.virtual_apic_map.hva;
-	vppr = *((u32 *)(vapic_page + APIC_PROCPRI));
-
-	return ((rvi & 0xf0) > (vppr & 0xf0));
-}
-
 void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -5086,14 +5063,19 @@ int vmx_nmi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
 	return !vmx_nmi_blocked(vcpu);
 }
 
+bool __vmx_interrupt_blocked(struct kvm_vcpu *vcpu)
+{
+	return !(vmx_get_rflags(vcpu) & X86_EFLAGS_IF) ||
+	       (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
+		(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS));
+}
+
 bool vmx_interrupt_blocked(struct kvm_vcpu *vcpu)
 {
 	if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
 		return false;
 
-	return !(vmx_get_rflags(vcpu) & X86_EFLAGS_IF) ||
-	       (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
-		(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS));
+	return __vmx_interrupt_blocked(vcpu);
 }
 
 int vmx_interrupt_allowed(struct kvm_vcpu *vcpu, bool for_injection)
@@ -8610,9 +8592,9 @@ static void __vmx_exit(void)
 static void vmx_exit(void)
 {
 	kvm_exit();
+	__vmx_exit();
 	kvm_x86_vendor_exit();
 
-	__vmx_exit();
 }
 module_exit(vmx_exit);
 

arch/x86/kvm/vmx/vmx.h

@@ -406,6 +406,7 @@ u64 construct_eptp(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
 bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu);
 void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu);
 bool vmx_nmi_blocked(struct kvm_vcpu *vcpu);
+bool __vmx_interrupt_blocked(struct kvm_vcpu *vcpu);
 bool vmx_interrupt_blocked(struct kvm_vcpu *vcpu);
 bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu);
 void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked);

arch/x86/kvm/vmx/x86_ops.h

@@ -48,7 +48,6 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
 void vmx_apicv_pre_state_restore(struct kvm_vcpu *vcpu);
 void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr);
 void vmx_hwapic_isr_update(int max_isr);
-bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu);
 int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu);
 void vmx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
 			   int trig_mode, int vector);

arch/x86/kvm/x86.c

@@ -10557,7 +10557,7 @@ static int kvm_check_and_inject_events(struct kvm_vcpu *vcpu,
 
 	if (is_guest_mode(vcpu) &&
 	    kvm_x86_ops.nested_ops->has_events &&
-	    kvm_x86_ops.nested_ops->has_events(vcpu))
+	    kvm_x86_ops.nested_ops->has_events(vcpu, true))
 		*req_immediate_exit = true;
 
 	/*
@@ -11255,7 +11255,10 @@ static inline int vcpu_block(struct kvm_vcpu *vcpu)
 	 * causes a spurious wakeup from HLT).
 	 */
 	if (is_guest_mode(vcpu)) {
-		if (kvm_check_nested_events(vcpu) < 0)
+		int r = kvm_check_nested_events(vcpu);
+
+		WARN_ON_ONCE(r == -EBUSY);
+		if (r < 0)
 			return 0;
 	}
 
@@ -13142,12 +13145,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 		kvm_arch_free_memslot(kvm, old);
 }
 
-static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
-{
-	return (is_guest_mode(vcpu) &&
-		static_call(kvm_x86_guest_apic_has_interrupt)(vcpu));
-}
-
 static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
 {
 	if (!list_empty_careful(&vcpu->async_pf.done))
@@ -13181,17 +13178,15 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
 	if (kvm_test_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, vcpu))
 		return true;
 
-	if (kvm_arch_interrupt_allowed(vcpu) &&
-	    (kvm_cpu_has_interrupt(vcpu) ||
-	    kvm_guest_apic_has_interrupt(vcpu)))
+	if (kvm_arch_interrupt_allowed(vcpu) && kvm_cpu_has_interrupt(vcpu))
 		return true;
 
 	if (kvm_hv_has_stimer_pending(vcpu))
 		return true;
 
 	if (is_guest_mode(vcpu) &&
 	    kvm_x86_ops.nested_ops->has_events &&
-	    kvm_x86_ops.nested_ops->has_events(vcpu))
+	    kvm_x86_ops.nested_ops->has_events(vcpu, false))
 		return true;
 
 	if (kvm_xen_has_pending_events(vcpu))