KVM: x86: Fix PV IPIs for 32-bit KVM host

The recognition of the KVM_HC_SEND_IPI hypercall was unintentionally
wrapped in "#ifdef CONFIG_X86_64", causing 32-bit KVM hosts to reject
any and all PV IPI requests despite advertising the feature.  This
results in all KVM paravirtualized guests hanging during SMP boot due
to IPIs never being delivered.

Fixes: 4180bf1b655a ("KVM: X86: Implement "send IPI" hypercall")
Cc: stable@vger.kernel.org
Cc: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f14bb806aeedfd101e5ab1196bb137e30369db6e..d21dcad397e4c4eb8c03b96db01972d7c8262924 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7092,10 +7092,10 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
        case KVM_HC_CLOCK_PAIRING:
                ret = kvm_pv_clock_pairing(vcpu, a0, a1);
                break;
+#endif
        case KVM_HC_SEND_IPI:
                ret = kvm_pv_send_ipi(vcpu->kvm, a0, a1, a2, a3, op_64_bit);
                break;
-#endif
        default:
                ret = -KVM_ENOSYS;
                break;