[RFC PATCH 04/13] KVM: SVM: Only call vcpu_(un)blocking when AVIC is enabled.

From: Suravee Suthikulpanit
Date: Sun Feb 20 2022 - 21:23:00 EST


The kvm_x86_ops.vcpu_(un)blocking are needed by AVIC only.
Therefore, set the ops only when AVIC is enabled.

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
arch/x86/kvm/svm/avic.c | 12 ++++++++++--
arch/x86/kvm/svm/svm.c | 7 -------
arch/x86/kvm/svm/svm.h | 2 --
3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index abde08ca23ab..0040824e4376 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -996,7 +996,7 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu)
WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
}

-void avic_vcpu_blocking(struct kvm_vcpu *vcpu)
+static void avic_vcpu_blocking(struct kvm_vcpu *vcpu)
{
if (!kvm_vcpu_apicv_active(vcpu))
return;
@@ -1021,7 +1021,7 @@ void avic_vcpu_blocking(struct kvm_vcpu *vcpu)
preempt_enable();
}

-void avic_vcpu_unblocking(struct kvm_vcpu *vcpu)
+static void avic_vcpu_unblocking(struct kvm_vcpu *vcpu)
{
int cpu;

@@ -1057,6 +1057,14 @@ bool avic_hardware_setup(struct kvm_x86_ops *x86_ops)
pr_info("x2AVIC enabled\n");
}

+ if (avic_mode) {
+ x86_ops->vcpu_blocking = avic_vcpu_blocking;
+ x86_ops->vcpu_unblocking = avic_vcpu_unblocking;
+ } else {
+ x86_ops->vcpu_blocking = NULL;
+ x86_ops->vcpu_unblocking = NULL;
+ }
+
amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
return !!avic_mode;
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 3048f4b758d6..3687026f2859 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4531,8 +4531,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.prepare_guest_switch = svm_prepare_guest_switch,
.vcpu_load = svm_vcpu_load,
.vcpu_put = svm_vcpu_put,
- .vcpu_blocking = avic_vcpu_blocking,
- .vcpu_unblocking = avic_vcpu_unblocking,

.update_exception_bitmap = svm_update_exception_bitmap,
.get_msr_feature = svm_get_msr_feature,
@@ -4819,11 +4817,6 @@ static __init int svm_hardware_setup(void)

enable_apicv = avic = avic && avic_hardware_setup(&svm_x86_ops);

- if (!enable_apicv) {
- svm_x86_ops.vcpu_blocking = NULL;
- svm_x86_ops.vcpu_unblocking = NULL;
- }
-
if (vls) {
if (!npt_enabled ||
!boot_cpu_has(X86_FEATURE_V_VMSAVE_VMLOAD) ||
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index b53c83a44ec2..1a0bf6b853df 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -578,8 +578,6 @@ void svm_hwapic_isr_update(struct kvm_vcpu *vcpu, int max_isr);
bool svm_dy_apicv_has_pending_interrupt(struct kvm_vcpu *vcpu);
int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
uint32_t guest_irq, bool set);
-void avic_vcpu_blocking(struct kvm_vcpu *vcpu);
-void avic_vcpu_unblocking(struct kvm_vcpu *vcpu);
void avic_ring_doorbell(struct kvm_vcpu *vcpu);

/* sev.c */
--
2.25.1