x86: KVM guest: merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST

The distinction between CONFIG_KVM_CLOCK and CONFIG_KVM_GUEST is
not so clear anymore, as demonstrated by recent bugs caused by poor
handling of on/off combinations of these options.

Merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST.

Reported-By: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

5 files changed, 12 insertions, 20 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8ec3a1aa4abd..a42e2e99caae 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -573,23 +573,18 @@ config PARAVIRT_TIME_ACCOUNTING
 
 source "arch/x86/xen/Kconfig"
 
-config KVM_CLOCK
-        bool "KVM paravirtualized clock"
-        select PARAVIRT
-        select PARAVIRT_CLOCK
-        ---help---
-          Turning on this option will allow you to run a paravirtualized clock
-          when running over the KVM hypervisor. Instead of relying on a PIT
-          (or probably other) emulation by the underlying device model, the host
-          provides the guest with timing infrastructure such as time of day, and
-          system time
-
 config KVM_GUEST
-        bool "KVM Guest support"
+        bool "KVM Guest support (including kvmclock)"
+        select PARAVIRT
         select PARAVIRT
+        select PARAVIRT_CLOCK
+        default y if PARAVIRT_GUEST
         ---help---
           This option enables various optimizations for running under the KVM
-          hypervisor.
+          hypervisor. It includes a paravirtualized clock, so that instead
+          of relying on a PIT (or probably other) emulation by the
+          underlying device model, the host provides the guest with
+          timing infrastructure such as time of day, and system time
 
 source "arch/x86/lguest/Kconfig"
 
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 20f5697888bd..eb3e9d85e1f1 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -102,14 +102,14 @@ struct kvm_vcpu_pv_apf_data {
 extern void kvmclock_init(void);
 extern int kvm_register_clock(char *txt);
 
-#ifdef CONFIG_KVM_CLOCK
+#ifdef CONFIG_KVM_GUEST
 bool kvm_check_and_clear_guest_paused(void);
 #else
 static inline bool kvm_check_and_clear_guest_paused(void)
 {
         return false;
 }
-#endif /* CONFIG_KVMCLOCK */
+#endif /* CONFIG_KVM_GUEST */
 
 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  * trap that we will then rewrite to the appropriate instruction.
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8215e5652d97..7203298e0b83 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -81,8 +81,7 @@ obj-$(CONFIG_DEBUG_RODATA_TEST)	+= test_rodata.o
 obj-$(CONFIG_DEBUG_NX_TEST)     += test_nx.o
 obj-$(CONFIG_DEBUG_NMI_SELFTEST) += nmi_selftest.o
 
-obj-$(CONFIG_KVM_GUEST)         += kvm.o
-obj-$(CONFIG_KVM_CLOCK)         += kvmclock.o
+obj-$(CONFIG_KVM_GUEST)         += kvm.o kvmclock.o
 obj-$(CONFIG_PARAVIRT)          += paravirt.o paravirt_patch_$(BITS).o
 obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= paravirt-spinlocks.o
 obj-$(CONFIG_PARAVIRT_CLOCK)    += pvclock.o
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 1596cc8fd793..b3e5e51bc907 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -397,9 +397,7 @@ void kvm_disable_steal_time(void)
 #ifdef CONFIG_SMP
 static void __init kvm_smp_prepare_boot_cpu(void)
 {
-#ifdef CONFIG_KVM_CLOCK
         WARN_ON(kvm_register_clock("primary cpu clock"));
-#endif
         kvm_guest_cpu_init();
         native_smp_prepare_boot_cpu();
 }
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f4b9b80e1b95..b3386ae3438b 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -957,7 +957,7 @@ void __init setup_arch(char **cmdline_p)
         initmem_init();
         memblock_find_dma_reserve();
 
-#ifdef CONFIG_KVM_CLOCK
+#ifdef CONFIG_KVM_GUEST
         kvmclock_init();
 #endif