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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org
Cc: ajones@ventanamicro.com,
	Alex Williamson <alex.williamson@redhat.com>,
	x86@kernel.org,
	kbingham@kernel.org
Subject: [PATCH v2 4/5] x86, vfio, gdb: replace CONFIG_HAVE_KVM with IS_ENABLED(CONFIG_KVM)
Date: Mon,  8 Jan 2024 07:47:39 -0500
Message-Id: <20240108124740.114453-5-pbonzini@redhat.com>
In-Reply-To: <20240108124740.114453-1-pbonzini@redhat.com>
References: <20240108124740.114453-1-pbonzini@redhat.com>
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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.  And likewise there is no need to include code that uses
symbol_get in VFIO as that symbol_get would always fail.

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: x86@kernel.org
Cc: kbingham@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/hardirq.h           | 2 +-
 arch/x86/include/asm/idtentry.h          | 2 +-
 arch/x86/include/asm/irq.h               | 2 +-
 arch/x86/include/asm/irq_vectors.h       | 2 +-
 arch/x86/kernel/idt.c                    | 2 +-
 arch/x86/kernel/irq.c                    | 4 ++--
 drivers/vfio/vfio.h                      | 2 +-
 drivers/vfio/vfio_main.c                 | 4 ++--
 scripts/gdb/linux/constants.py.in        | 6 +++++-
 scripts/gdb/linux/interrupts.py          | 2 +-
 tools/arch/x86/include/asm/irq_vectors.h | 2 +-
 11 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 66837b8c67f1..fbc7722b87d1 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -15,7 +15,7 @@ typedef struct {
 	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;
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 13639e57e1f8..d9c86733d0db 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -675,7 +675,7 @@ DECLARE_IDTENTRY_SYSVEC(IRQ_WORK_VECTOR,		sysvec_irq_work);
 # 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);
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 836c170d3087..194dfff84cb1 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -29,7 +29,7 @@ struct irq_desc;
 
 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
 
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 3a19904c2db6..3f73ac3ed3a0 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -84,7 +84,7 @@
 #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
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 660b601f1d6c..d2bc67cbaf92 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -153,7 +153,7 @@ static const __initconst struct idt_data apic_idts[] = {
 #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),
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 11761c124545..35fde0107901 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -164,7 +164,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 #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);
@@ -290,7 +290,7 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_x86_platform_ipi)
 }
 #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;
 
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 307e3f29b527..c26d1ad68105 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -434,7 +434,7 @@ static inline void vfio_virqfd_exit(void)
 }
 #endif
 
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
 void vfio_device_put_kvm(struct vfio_device *device);
 #else
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 8d4995ada74a..3e595aabf320 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -16,7 +16,7 @@
 #include <linux/fs.h>
 #include <linux/idr.h>
 #include <linux/iommu.h>
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 #include <linux/kvm_host.h>
 #endif
 #include <linux/list.h>
@@ -383,7 +383,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
 void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
 {
 	void (*pfn)(struct kvm *kvm);
diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
index e810e0c27ff1..5cace7588e24 100644
--- a/scripts/gdb/linux/constants.py.in
+++ b/scripts/gdb/linux/constants.py.in
@@ -130,7 +130,11 @@ LX_CONFIG(CONFIG_X86_MCE_THRESHOLD)
 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)
diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py
index ef478e273791..66ae5c7690cf 100644
--- a/scripts/gdb/linux/interrupts.py
+++ b/scripts/gdb/linux/interrupts.py
@@ -151,7 +151,7 @@ def x86_show_interupts(prec):
         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')
diff --git a/tools/arch/x86/include/asm/irq_vectors.h b/tools/arch/x86/include/asm/irq_vectors.h
index 3a19904c2db6..3f73ac3ed3a0 100644
--- a/tools/arch/x86/include/asm/irq_vectors.h
+++ b/tools/arch/x86/include/asm/irq_vectors.h
@@ -84,7 +84,7 @@
 #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
-- 
2.39.1