KVM: define __KVM_HAVE_GUEST_DEBUG unconditionally

Since all architectures (for historical reasons) have to define
struct kvm_guest_debug_arch, and since userspace has to check
KVM_CHECK_EXTENSION(KVM_CAP_SET_GUEST_DEBUG) anyway, there is
no advantage in masking the capability #define itself.  Remove
the #define __KVM_HAVE_GUEST_DEBUG from architecture-specific
headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/arm64/include/uapi/asm/kvm.h

@@ -37,7 +37,6 @@
 #include <asm/ptrace.h>
 #include <asm/sve_context.h>
 
-#define __KVM_HAVE_GUEST_DEBUG
 #define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_VCPU_EVENTS
 

arch/powerpc/include/uapi/asm/kvm.h

@@ -28,7 +28,6 @@
 #define __KVM_HAVE_PPC_SMT
 #define __KVM_HAVE_IRQCHIP
 #define __KVM_HAVE_IRQ_LINE
-#define __KVM_HAVE_GUEST_DEBUG
 
 /* Not always available, but if it is, this is the correct offset.  */
 #define KVM_COALESCED_MMIO_PAGE_OFFSET 1

arch/s390/include/uapi/asm/kvm.h

@@ -12,7 +12,6 @@
 #include <linux/types.h>
 
 #define __KVM_S390
-#define __KVM_HAVE_GUEST_DEBUG
 
 struct kvm_s390_skeys {
 	__u64 start_gfn;

arch/x86/include/uapi/asm/kvm.h

@@ -42,7 +42,6 @@
 #define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_MSI
 #define __KVM_HAVE_USER_NMI
-#define __KVM_HAVE_GUEST_DEBUG
 #define __KVM_HAVE_MSIX
 #define __KVM_HAVE_MCE
 #define __KVM_HAVE_PIT_STATE2

include/uapi/linux/kvm.h

@@ -16,6 +16,11 @@
 
 #define KVM_API_VERSION 12
 
+/*
+ * Backwards-compatible definitions.
+ */
+#define __KVM_HAVE_GUEST_DEBUG
+
 /* for KVM_SET_USER_MEMORY_REGION */
 struct kvm_userspace_memory_region {
 	__u32 slot;
@@ -682,9 +687,7 @@ struct kvm_enable_cap {
 /* Bug in KVM_SET_USER_MEMORY_REGION fixed: */
 #define KVM_CAP_DESTROY_MEMORY_REGION_WORKS 21
 #define KVM_CAP_USER_NMI 22
-#ifdef __KVM_HAVE_GUEST_DEBUG
 #define KVM_CAP_SET_GUEST_DEBUG 23
-#endif
 #ifdef __KVM_HAVE_PIT
 #define KVM_CAP_REINJECT_CONTROL 24
 #endif