[PATCH 05/22] KVM: x86: Use static_call() for .vcpu_deliver_sipi_vector()

From: Sean Christopherson
Date: Thu Jan 27 2022 - 19:53:46 EST


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@xxxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/kvm/lapic.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index a87632641a13..eb93aa439d61 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -117,5 +117,6 @@ KVM_X86_OP(enable_direct_tlbflush)
KVM_X86_OP(migrate_timers)
KVM_X86_OP(msr_filter_changed)
KVM_X86_OP(complete_emulated_msr)
+KVM_X86_OP(vcpu_deliver_sipi_vector)

#undef KVM_X86_OP
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d7e6fde82d25..dc4bc9eea81c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2928,7 +2928,7 @@ 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;
}
}
--
2.35.0.rc0.227.g00780c9af4-goog