KVM: x86: Introduce kvm_x86_call() to simplify static calls of kvm_x86_ops

Introduces kvm_x86_call(), to streamline the usage of static calls of
kvm_x86_ops. The current implementation of these calls is verbose and
could lead to alignment challenges. This makes the code susceptible to
exceeding the "80 columns per single line of code" limit as defined in
the coding-style document. Another issue with the existing implementation
is that the addition of kvm_x86_ prefix to hooks at the static_call sites
hinders code readability and navigation. kvm_x86_call() is added to
improve code readability and maintainability, while adhering to the coding
style guidelines.

Signed-off-by: Wei Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

Author: wei-w-wang

arch/x86/include/asm/kvm_host.h

@@ -1874,6 +1874,8 @@ extern bool __read_mostly allow_smaller_maxphyaddr;
 extern bool __read_mostly enable_apicv;
 extern struct kvm_x86_ops kvm_x86_ops;
 
+#define kvm_x86_call(func) static_call(kvm_x86_##func)
+
 #define KVM_X86_OP(func) \
 	DECLARE_STATIC_CALL(kvm_x86_##func, *(((struct kvm_x86_ops *)0)->func));
 #define KVM_X86_OP_OPTIONAL KVM_X86_OP
@@ -1897,7 +1899,7 @@ void kvm_arch_free_vm(struct kvm *kvm);
 static inline int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
 {
 	if (kvm_x86_ops.flush_remote_tlbs &&
-	    !static_call(kvm_x86_flush_remote_tlbs)(kvm))
+	    !kvm_x86_call(flush_remote_tlbs)(kvm))
 		return 0;
 	else
 		return -ENOTSUPP;
@@ -1910,7 +1912,7 @@ static inline int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn,
 	if (!kvm_x86_ops.flush_remote_tlbs_range)
 		return -EOPNOTSUPP;
 
-	return static_call(kvm_x86_flush_remote_tlbs_range)(kvm, gfn, nr_pages);
+	return kvm_x86_call(flush_remote_tlbs_range)(kvm, gfn, nr_pages);
 }
 #endif /* CONFIG_HYPERV */
 
@@ -2309,12 +2311,12 @@ static inline bool kvm_irq_is_postable(struct kvm_lapic_irq *irq)
 
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
 {
-	static_call(kvm_x86_vcpu_blocking)(vcpu);
+	kvm_x86_call(vcpu_blocking)(vcpu);
 }
 
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
 {
-	static_call(kvm_x86_vcpu_unblocking)(vcpu);
+	kvm_x86_call(vcpu_unblocking)(vcpu);
 }
 
 static inline int kvm_cpu_get_apicid(int mps_cpu)

arch/x86/kvm/cpuid.c

@@ -400,7 +400,7 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 						    vcpu->arch.cpuid_nent));
 
 	/* Invoke the vendor callback only after the above state is updated. */
-	static_call(kvm_x86_vcpu_after_set_cpuid)(vcpu);
+	kvm_x86_call(vcpu_after_set_cpuid)(vcpu);
 
 	/*
 	 * Except for the MMU, which needs to do its thing any vendor specific

arch/x86/kvm/hyperv.c

@@ -1417,7 +1417,7 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
 		}
 
 		/* vmcall/vmmcall */
-		static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
+		kvm_x86_call(patch_hypercall)(vcpu, instructions + i);
 		i += 3;
 
 		/* ret */
@@ -1986,7 +1986,7 @@ int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
 		 */
 		gva = entries[i] & PAGE_MASK;
 		for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++)
-			static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
+			kvm_x86_call(flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
 
 		++vcpu->stat.tlb_flush;
 	}
@@ -2527,7 +2527,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
 	 * hypercall generates UD from non zero cpl and real mode
 	 * per HYPER-V spec
 	 */
-	if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
+	if (kvm_x86_call(get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
 		kvm_queue_exception(vcpu, UD_VECTOR);
 		return 1;
 	}

arch/x86/kvm/irq.c

@@ -157,7 +157,7 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
 {
 	__kvm_migrate_apic_timer(vcpu);
 	__kvm_migrate_pit_timer(vcpu);
-	static_call(kvm_x86_migrate_timers)(vcpu);
+	kvm_x86_call(migrate_timers)(vcpu);
 }
 
 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)

arch/x86/kvm/kvm_cache_regs.h

@@ -98,7 +98,7 @@ static inline unsigned long kvm_register_read_raw(struct kvm_vcpu *vcpu, int reg
 		return 0;
 
 	if (!kvm_register_is_available(vcpu, reg))
-		static_call(kvm_x86_cache_reg)(vcpu, reg);
+		kvm_x86_call(cache_reg)(vcpu, reg);
 
 	return vcpu->arch.regs[reg];
 }
@@ -138,7 +138,7 @@ static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
 	might_sleep();  /* on svm */
 
 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
-		static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_PDPTR);
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_PDPTR);
 
 	return vcpu->arch.walk_mmu->pdptrs[index];
 }
@@ -153,7 +153,7 @@ static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
 	ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
 	if ((tmask & vcpu->arch.cr0_guest_owned_bits) &&
 	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR0))
-		static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR0);
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR0);
 	return vcpu->arch.cr0 & mask;
 }
 
@@ -175,7 +175,7 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
 	ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS;
 	if ((tmask & vcpu->arch.cr4_guest_owned_bits) &&
 	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR4))
-		static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR4);
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR4);
 	return vcpu->arch.cr4 & mask;
 }
 
@@ -190,7 +190,7 @@ static __always_inline bool kvm_is_cr4_bit_set(struct kvm_vcpu *vcpu,
 static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
 {
 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
-		static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR3);
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR3);
 	return vcpu->arch.cr3;
 }
 

arch/x86/kvm/lapic.c

@@ -738,8 +738,8 @@ static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
 	if (unlikely(apic->apicv_active)) {
 		/* need to update RVI */
 		kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR);
-		static_call(kvm_x86_hwapic_irr_update)(apic->vcpu,
-							    apic_find_highest_irr(apic));
+		kvm_x86_call(hwapic_irr_update)(apic->vcpu,
+						apic_find_highest_irr(apic));
 	} else {
 		apic->irr_pending = false;
 		kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR);
@@ -765,7 +765,7 @@ static inline void apic_set_isr(int vec, struct kvm_lapic *apic)
 	 * just set SVI.
 	 */
 	if (unlikely(apic->apicv_active))
-		static_call(kvm_x86_hwapic_isr_update)(vec);
+		kvm_x86_call(hwapic_isr_update)(vec);
 	else {
 		++apic->isr_count;
 		BUG_ON(apic->isr_count > MAX_APIC_VECTOR);
@@ -810,7 +810,7 @@ static inline void apic_clear_isr(int vec, struct kvm_lapic *apic)
 	 * and must be left alone.
 	 */
 	if (unlikely(apic->apicv_active))
-		static_call(kvm_x86_hwapic_isr_update)(apic_find_highest_isr(apic));
+		kvm_x86_call(hwapic_isr_update)(apic_find_highest_isr(apic));
 	else {
 		--apic->isr_count;
 		BUG_ON(apic->isr_count < 0);
@@ -946,7 +946,7 @@ static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr)
 {
 	int highest_irr;
 	if (kvm_x86_ops.sync_pir_to_irr)
-		highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu);
+		highest_irr = kvm_x86_call(sync_pir_to_irr)(apic->vcpu);
 	else
 		highest_irr = apic_find_highest_irr(apic);
 	if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr)
@@ -1338,8 +1338,8 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 						       apic->regs + APIC_TMR);
 		}
 
-		static_call(kvm_x86_deliver_interrupt)(apic, delivery_mode,
-						       trig_mode, vector);
+		kvm_x86_call(deliver_interrupt)(apic, delivery_mode,
+						trig_mode, vector);
 		break;
 
 	case APIC_DM_REMRD:
@@ -2105,7 +2105,7 @@ static void cancel_hv_timer(struct kvm_lapic *apic)
 {
 	WARN_ON(preemptible());
 	WARN_ON(!apic->lapic_timer.hv_timer_in_use);
-	static_call(kvm_x86_cancel_hv_timer)(apic->vcpu);
+	kvm_x86_call(cancel_hv_timer)(apic->vcpu);
 	apic->lapic_timer.hv_timer_in_use = false;
 }
 
@@ -2122,7 +2122,7 @@ static bool start_hv_timer(struct kvm_lapic *apic)
 	if (!ktimer->tscdeadline)
 		return false;
 
-	if (static_call(kvm_x86_set_hv_timer)(vcpu, ktimer->tscdeadline, &expired))
+	if (kvm_x86_call(set_hv_timer)(vcpu, ktimer->tscdeadline, &expired))
 		return false;
 
 	ktimer->hv_timer_in_use = true;
@@ -2577,7 +2577,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 
 	if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) {
 		kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
-		static_call(kvm_x86_set_virtual_apic_mode)(vcpu);
+		kvm_x86_call(set_virtual_apic_mode)(vcpu);
 	}
 
 	apic->base_address = apic->vcpu->arch.apic_base &
@@ -2687,7 +2687,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
 	u64 msr_val;
 	int i;
 
-	static_call(kvm_x86_apicv_pre_state_restore)(vcpu);
+	kvm_x86_call(apicv_pre_state_restore)(vcpu);
 
 	if (!init_event) {
 		msr_val = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE;
@@ -2742,9 +2742,9 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
 	vcpu->arch.pv_eoi.msr_val = 0;
 	apic_update_ppr(apic);
 	if (apic->apicv_active) {
-		static_call(kvm_x86_apicv_post_state_restore)(vcpu);
-		static_call(kvm_x86_hwapic_irr_update)(vcpu, -1);
-		static_call(kvm_x86_hwapic_isr_update)(-1);
+		kvm_x86_call(apicv_post_state_restore)(vcpu);
+		kvm_x86_call(hwapic_irr_update)(vcpu, -1);
+		kvm_x86_call(hwapic_isr_update)(-1);
 	}
 
 	vcpu->arch.apic_arb_prio = 0;
@@ -2840,7 +2840,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
 	vcpu->arch.apic = apic;
 
 	if (kvm_x86_ops.alloc_apic_backing_page)
-		apic->regs = static_call(kvm_x86_alloc_apic_backing_page)(vcpu);
+		apic->regs = kvm_x86_call(alloc_apic_backing_page)(vcpu);
 	else
 		apic->regs = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
 	if (!apic->regs) {
@@ -3019,7 +3019,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
 	struct kvm_lapic *apic = vcpu->arch.apic;
 	int r;
 
-	static_call(kvm_x86_apicv_pre_state_restore)(vcpu);
+	kvm_x86_call(apicv_pre_state_restore)(vcpu);
 
 	kvm_lapic_set_base(vcpu, vcpu->arch.apic_base);
 	/* set SPIV separately to get count of SW disabled APICs right */
@@ -3046,9 +3046,10 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
 	kvm_lapic_set_reg(apic, APIC_TMCCT, 0);
 	kvm_apic_update_apicv(vcpu);
 	if (apic->apicv_active) {
-		static_call(kvm_x86_apicv_post_state_restore)(vcpu);
-		static_call(kvm_x86_hwapic_irr_update)(vcpu, apic_find_highest_irr(apic));
-		static_call(kvm_x86_hwapic_isr_update)(apic_find_highest_isr(apic));
+		kvm_x86_call(apicv_post_state_restore)(vcpu);
+		kvm_x86_call(hwapic_irr_update)(vcpu,
+						apic_find_highest_irr(apic));
+		kvm_x86_call(hwapic_isr_update)(apic_find_highest_isr(apic));
 	}
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
 	if (ioapic_in_kernel(vcpu->kvm))
@@ -3336,7 +3337,8 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
 			/* evaluate pending_events before reading the vector */
 			smp_rmb();
 			sipi_vector = apic->sipi_vector;
-			static_call(kvm_x86_vcpu_deliver_sipi_vector)(vcpu, sipi_vector);
+			kvm_x86_call(vcpu_deliver_sipi_vector)(vcpu,
+							       sipi_vector);
 			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 		}
 	}

arch/x86/kvm/lapic.h

@@ -235,7 +235,7 @@ static inline bool kvm_apic_has_pending_init_or_sipi(struct kvm_vcpu *vcpu)
 static inline bool kvm_apic_init_sipi_allowed(struct kvm_vcpu *vcpu)
 {
 	return !is_smm(vcpu) &&
-	       !static_call(kvm_x86_apic_init_signal_blocked)(vcpu);
+	       !kvm_x86_call(apic_init_signal_blocked)(vcpu);
 }
 
 static inline bool kvm_lowest_prio_delivery(struct kvm_lapic_irq *irq)

arch/x86/kvm/mmu.h

@@ -138,8 +138,8 @@ static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu)
 	if (!VALID_PAGE(root_hpa))
 		return;
 
-	static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa,
-					  vcpu->arch.mmu->root_role.level);
+	kvm_x86_call(load_mmu_pgd)(vcpu, root_hpa,
+				   vcpu->arch.mmu->root_role.level);
 }
 
 static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu,
@@ -174,7 +174,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 {
 	/* strip nested paging fault error codes */
 	unsigned int pfec = access;
-	unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu);
+	unsigned long rflags = kvm_x86_call(get_rflags)(vcpu);
 
 	/*
 	 * For explicit supervisor accesses, SMAP is disabled if EFLAGS.AC = 1.

arch/x86/kvm/mmu/mmu.c

@@ -4331,7 +4331,7 @@ static u8 kvm_max_private_mapping_level(struct kvm *kvm, kvm_pfn_t pfn,
 	if (max_level == PG_LEVEL_4K)
 		return PG_LEVEL_4K;
 
-	req_max_level = static_call(kvm_x86_private_max_mapping_level)(kvm, pfn);
+	req_max_level = kvm_x86_call(private_max_mapping_level)(kvm, pfn);
 	if (req_max_level)
 		max_level = min(max_level, req_max_level);
 
@@ -5741,7 +5741,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 	 * stale entries.  Flushing on alloc also allows KVM to skip the TLB
 	 * flush when freeing a root (see kvm_tdp_mmu_put_root()).
 	 */
-	static_call(kvm_x86_flush_tlb_current)(vcpu);
+	kvm_x86_call(flush_tlb_current)(vcpu);
 out:
 	return r;
 }
@@ -6113,7 +6113,7 @@ void kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 		if (is_noncanonical_address(addr, vcpu))
 			return;
 
-		static_call(kvm_x86_flush_tlb_gva)(vcpu, addr);
+		kvm_x86_call(flush_tlb_gva)(vcpu, addr);
 	}
 
 	if (!mmu->sync_spte)

arch/x86/kvm/mmu/spte.c

@@ -210,8 +210,8 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 		spte |= PT_PAGE_SIZE_MASK;
 
 	if (shadow_memtype_mask)
-		spte |= static_call(kvm_x86_get_mt_mask)(vcpu, gfn,
-							 kvm_is_mmio_pfn(pfn));
+		spte |= kvm_x86_call(get_mt_mask)(vcpu, gfn,
+						  kvm_is_mmio_pfn(pfn));
 	if (host_writable)
 		spte |= shadow_host_writable_mask;
 	else