[PATCH v2] KVM: SVM: Fix implicit declaration for __default_cpu_present_to_apicid()

[Suravee Suthikulpanit]

The commit 8221c1370056 ("svm: Manage vcpu load/unload when enable AVIC")
introduces a build error due to implicit function declaration
when #ifdef CONFIG_X86_32 and #ifndef CONFIG_X86_LOCAL_APIC
(as reported by Kbuild test robot i386-randconfig-x0-06121009).

So, this patch introduces kvm_cpu_get_apicid() wrapper
around __default_cpu_present_to_apicid() with additional
handling if CONFIG_X86_LOCAL_APIC is not defined.

Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Fixes: commit 8221c1370056 ("svm: Manage vcpu load/unload when enable AVIC")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 11 +++++++++++
 arch/x86/kvm/svm.c              |  6 +++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a714cc2..fe1c5c3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -27,6 +27,7 @@
 #include <linux/irqbypass.h>
 #include <linux/hyperv.h>
 
+#include <asm/apic.h>
 #include <asm/pvclock-abi.h>
 #include <asm/desc.h>
 #include <asm/mtrr.h>
@@ -1370,4 +1371,14 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
 
 static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 
+static inline int kvm_cpu_get_apicid(int mps_cpu)
+{
+#ifdef CONFIG_X86_LOCAL_APIC
+	return __default_cpu_present_to_apicid(mps_cpu);
+#else
+	WARN_ON_ONCE(1);
+	return BAD_APICID;
+#endif
+}
+
 #endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 5b12438..0d2aa13 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1402,7 +1402,7 @@ avic_update_iommu(struct kvm_vcpu *vcpu, int cpu, phys_addr_t pa, bool r)
 static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run)
 {
 	u64 entry;
-	int h_physical_id = __default_cpu_present_to_apicid(vcpu->cpu);
+	int h_physical_id = kvm_cpu_get_apicid(vcpu->cpu);
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	if (!kvm_vcpu_apicv_active(vcpu))
@@ -1434,7 +1434,7 @@ static void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	u64 entry;
 	/* ID = 0xff (broadcast), ID > 0xff (reserved) */
-	int h_physical_id = __default_cpu_present_to_apicid(cpu);
+	int h_physical_id = kvm_cpu_get_apicid(cpu);
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	if (!kvm_vcpu_apicv_active(vcpu))
@@ -4328,7 +4328,7 @@ static void svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
 
 	if (avic_vcpu_is_running(vcpu))
 		wrmsrl(SVM_AVIC_DOORBELL,
-		       __default_cpu_present_to_apicid(vcpu->cpu));
+		       kvm_cpu_get_apicid(vcpu->cpu));
 	else
 		kvm_vcpu_wake_up(vcpu);
 }
-- 
1.9.1