KVM: x86: Use static_call() for .vcpu_deliver_sipi_vector()

Define and use a static_call() for kvm_x86_ops.vcpu_deliver_sipi_vector(),
mostly so that the op is defined in kvm-x86-ops.h.  This will allow using
KVM_X86_OP in vendor code to wire up the implementation.  Any performance
gains eeked out by using static_call() is a happy bonus and not the
primary motiviation.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220128005208.4008533-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 4fb9b7d..955f4d8 100644 (file)
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -122,6 +122,7 @@ KVM_X86_OP_NULL(enable_direct_tlbflush)
 KVM_X86_OP_NULL(migrate_timers)
 KVM_X86_OP(msr_filter_changed)
 KVM_X86_OP_NULL(complete_emulated_msr)
+KVM_X86_OP(vcpu_deliver_sipi_vector)
 
 #undef KVM_X86_OP
 #undef KVM_X86_OP_NULL

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 9322e63..5fe5072 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2933,7 +2933,7 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
                        /* evaluate pending_events before reading the vector */
                        smp_rmb();
                        sipi_vector = apic->sipi_vector;
-                       kvm_x86_ops.vcpu_deliver_sipi_vector(vcpu, sipi_vector);
+                       static_call(kvm_x86_vcpu_deliver_sipi_vector)(vcpu, sipi_vector);
                        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
                }
        }