x86: replace CONFIG_HAVE_KVM with IS_ENABLED(CONFIG_KVM)

It is more accurate to check if KVM is enabled, instead of having the
architecture say so. Architectures always "have" KVM, so for example
checking CONFIG_HAVE_KVM in x86 code is pointless, but if KVM is disabled
in a specific build, there is no need for support code.

Alternatively, many of the #ifdefs could simply be deleted. However,
this would add completely dead code. For example, when KVM is disabled,
there should not be any posted interrupts, i.e. NOT wiring up the "dummy"
handlers and treating IRQs on those vectors as spurious is the right
thing to do.

Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Paolo Bonzini <[e-mail]>

arch/x86/include/asm/hardirq.h

···
 	unsigned int irq_spurious_count;
 	unsigned int icr_read_retry_count;
 #endif
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 	unsigned int kvm_posted_intr_ipis;
 	unsigned int kvm_posted_intr_wakeup_ipis;
 	unsigned int kvm_posted_intr_nested_ipis;

arch/x86/include/asm/idtentry.h

···
 # endif
 #endif
 
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_VECTOR,		sysvec_kvm_posted_intr_ipi);
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_WAKEUP_VECTOR,	sysvec_kvm_posted_intr_wakeup_ipi);
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR,	sysvec_kvm_posted_intr_nested_ipi);

arch/x86/include/asm/irq.h

···
 
 extern void fixup_irqs(void);
 
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
 #endif
 

arch/x86/include/asm/irq_vectors.h

···
 #define HYPERVISOR_CALLBACK_VECTOR	0xf3
 
 /* Vector for KVM to deliver posted interrupt IPI */
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 #define POSTED_INTR_VECTOR		0xf2
 #define POSTED_INTR_WAKEUP_VECTOR	0xf1
 #define POSTED_INTR_NESTED_VECTOR	0xf0

arch/x86/kernel/idt.c

···
 #ifdef CONFIG_X86_LOCAL_APIC
 	INTG(LOCAL_TIMER_VECTOR,		asm_sysvec_apic_timer_interrupt),
 	INTG(X86_PLATFORM_IPI_VECTOR,		asm_sysvec_x86_platform_ipi),
-# ifdef CONFIG_HAVE_KVM
+# if IS_ENABLED(CONFIG_KVM)
 	INTG(POSTED_INTR_VECTOR,		asm_sysvec_kvm_posted_intr_ipi),
 	INTG(POSTED_INTR_WAKEUP_VECTOR,		asm_sysvec_kvm_posted_intr_wakeup_ipi),
 	INTG(POSTED_INTR_NESTED_VECTOR,		asm_sysvec_kvm_posted_intr_nested_ipi),

arch/x86/kernel/irq.c

···
 #if defined(CONFIG_X86_IO_APIC)
 	seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
 #endif
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 	seq_printf(p, "%*s: ", prec, "PIN");
 	for_each_online_cpu(j)
 		seq_printf(p, "%10u ", irq_stats(j)->kvm_posted_intr_ipis);
···
 }
 #endif
 
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 static void dummy_handler(void) {}
 static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
 

scripts/gdb/linux/constants.py.in

···
 LX_CONFIG(CONFIG_X86_MCE_AMD)
 LX_CONFIG(CONFIG_X86_MCE)
 LX_CONFIG(CONFIG_X86_IO_APIC)
-LX_CONFIG(CONFIG_HAVE_KVM)
+/*
+ * CONFIG_KVM can be "m" but it affects common code too.  Use CONFIG_KVM_COMMON
+ * as a proxy for IS_ENABLED(CONFIG_KVM).
+ */
+LX_CONFIG_KVM = IS_BUILTIN(CONFIG_KVM_COMMON)
 LX_CONFIG(CONFIG_NUMA)
 LX_CONFIG(CONFIG_ARM64)
 LX_CONFIG(CONFIG_ARM64_4K_PAGES)

scripts/gdb/linux/interrupts.py

···
         if cnt is not None:
             text += "%*s: %10u\n" % (prec, "MIS", cnt['counter'])
 
-    if constants.LX_CONFIG_HAVE_KVM:
+    if constants.LX_CONFIG_KVM:
         text += x86_show_irqstat(prec, "PIN", 'kvm_posted_intr_ipis', 'Posted-interrupt notification event')
         text += x86_show_irqstat(prec, "NPI", 'kvm_posted_intr_nested_ipis', 'Nested posted-interrupt event')
         text += x86_show_irqstat(prec, "PIW", 'kvm_posted_intr_wakeup_ipis', 'Posted-interrupt wakeup event')

tools/arch/x86/include/asm/irq_vectors.h

···
 #define HYPERVISOR_CALLBACK_VECTOR	0xf3
 
 /* Vector for KVM to deliver posted interrupt IPI */
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 #define POSTED_INTR_VECTOR		0xf2
 #define POSTED_INTR_WAKEUP_VECTOR	0xf1
 #define POSTED_INTR_NESTED_VECTOR	0xf0