[PATCH 1/4] KVM: introduce CONFIG_KVM_COMMON

[Paolo Bonzini <pbonzini@redhat.com>]

CONFIG_HAVE_KVM is currently used by some architectures to either
enabled the KVM config proper, or to enable host-side code that is
not part of the KVM module.  However, the "select" statement in
virt/kvm/Kconfig corresponds to a third meaning, namely to
enable common Kconfigs required by all architectures that support
KVM.

These three meanings can be replaced respectively by an
architecture-specific Kconfig, by IS_ENABLED(CONFIG_KVM), or by
a new Kconfig symbol that is in turn selected by the
architecture-specific "config KVM".

Start by introducing such a new Kconfig symbol, CONFIG_KVM_COMMON.
Unlike CONFIG_HAVE_KVM, it is selected by CONFIG_KVM, not by
architecture code.

Fixes: 8132d887a702 ("KVM: remove CONFIG_HAVE_KVM_EVENTFD", 2023-12-08)
Cc: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/arm64/kvm/Kconfig     | 1 +
 arch/loongarch/kvm/Kconfig | 1 +
 arch/mips/kvm/Kconfig      | 1 +
 arch/powerpc/kvm/Kconfig   | 1 +
 arch/riscv/kvm/Kconfig     | 1 +
 arch/s390/kvm/Kconfig      | 1 +
 arch/x86/kvm/Kconfig       | 1 +
 virt/kvm/Kconfig           | 3 +++
 8 files changed, 10 insertions(+)

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index b07c60c9737d..ad5ce0454f17 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -21,6 +21,7 @@ if VIRTUALIZATION
 menuconfig KVM
 	bool "Kernel-based Virtual Machine (KVM) support"
 	depends on HAVE_KVM
+	select KVM_COMMON
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_GENERIC_MMU_NOTIFIER
 	select PREEMPT_NOTIFIERS
diff --git a/arch/loongarch/kvm/Kconfig b/arch/loongarch/kvm/Kconfig
index daba4cd5e87d..3b284b7e63ad 100644
--- a/arch/loongarch/kvm/Kconfig
+++ b/arch/loongarch/kvm/Kconfig
@@ -23,6 +23,7 @@ config KVM
 	depends on HAVE_KVM
 	select HAVE_KVM_DIRTY_RING_ACQ_REL
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
+	select KVM_COMMON
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_GENERIC_MMU_NOTIFIER
diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
index 428141b0b48f..2eb119e78b6e 100644
--- a/arch/mips/kvm/Kconfig
+++ b/arch/mips/kvm/Kconfig
@@ -21,6 +21,7 @@ config KVM
 	depends on MIPS_FP_SUPPORT
 	select EXPORT_UASM
 	select PREEMPT_NOTIFIERS
+	select KVM_COMMON
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
 	select KVM_MMIO
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index b47196085a42..5da535e20b6a 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -20,6 +20,7 @@ if VIRTUALIZATION
 config KVM
 	bool
 	select PREEMPT_NOTIFIERS
+	select KVM_COMMON
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
 	select KVM_VFIO
 	select IRQ_BYPASS_MANAGER
diff --git a/arch/riscv/kvm/Kconfig b/arch/riscv/kvm/Kconfig
index 1fd76aee3b71..55f81377d260 100644
--- a/arch/riscv/kvm/Kconfig
+++ b/arch/riscv/kvm/Kconfig
@@ -24,6 +24,7 @@ config KVM
 	select HAVE_KVM_IRQ_ROUTING
 	select HAVE_KVM_MSI
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
+	select KVM_COMMON
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_MMIO
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index bb6d90351119..f89bedbe63bd 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -25,6 +25,7 @@ config KVM
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
 	select KVM_ASYNC_PF
 	select KVM_ASYNC_PF_SYNC
+	select KVM_COMMON
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_IRQ_ROUTING
 	select HAVE_KVM_INVALID_WAKEUPS
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index b07247b0b958..c8e62a371d24 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -24,6 +24,7 @@ config KVM
 	depends on HIGH_RES_TIMERS
 	depends on X86_LOCAL_APIC
 	select PREEMPT_NOTIFIERS
+	select KVM_COMMON
 	select KVM_GENERIC_MMU_NOTIFIER
 	select HAVE_KVM_IRQCHIP
 	select HAVE_KVM_PFNCACHE
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 6793211a0b64..cce5c03ecc92 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -3,6 +3,9 @@
 
 config HAVE_KVM
        bool
+
+config KVM_COMMON
+       bool
        select EVENTFD
 
 config HAVE_KVM_PFNCACHE
-- 
2.39.1