diff options
| author | Yi Wang <foxywang@tencent.com> | 2024-05-06 18:17:50 +0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-06-11 14:18:40 -0700 |
| commit | e3c89f5dd11df791b55b320c3869a97414ef5d06 (patch) | |
| tree | ed6d459e43724ce9c490ecadbdb12979ea340588 | |
| parent | fbe4a7e881d4408bfabbb4fd538f10fd686cd8ab (diff) | |
KVM: x86: Don't re-setup empty IRQ routing when KVM_CAP_SPLIT_IRQCHIP
Now that KVM sets up empty IRQ routing during VM creation, don't recreate
empty routing during KVM_CAP_SPLIT_IRQCHIP. Setting IRQ routes during
KVM_CAP_SPLIT_IRQCHIP can result in 20+ milliseconds of delay due to the
synchronize_srcu_expedited() call in kvm_set_irq_routing().
Note, the empty routing is guaranteed to be intact as KVM x86 only allows
changing the IRQ routing after an in-kernel IRQCHIP has been created, and
KVM_CAP_SPLIT_IRQCHIP is disallowed after creating an IRQCHIP.
Signed-off-by: Yi Wang <foxywang@tencent.com>
Link: https://lore.kernel.org/r/20240506101751.3145407-3-foxywang@tencent.com
[sean: massage changelog, remove unused empty_routing array]
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/irq.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/irq_comm.c | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
3 files changed, 0 insertions, 11 deletions
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index c2d7cfe82d00..76d46b2f41dd 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -106,7 +106,6 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu); int apic_has_pending_timer(struct kvm_vcpu *vcpu); int kvm_setup_default_irq_routing(struct kvm *kvm); -int kvm_setup_empty_irq_routing(struct kvm *kvm); int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, struct kvm_lapic_irq *irq, struct dest_map *dest_map); diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c index 68f3f6c26046..8136695f7b96 100644 --- a/arch/x86/kvm/irq_comm.c +++ b/arch/x86/kvm/irq_comm.c @@ -395,13 +395,6 @@ int kvm_setup_default_irq_routing(struct kvm *kvm) ARRAY_SIZE(default_routing), 0); } -static const struct kvm_irq_routing_entry empty_routing[] = {}; - -int kvm_setup_empty_irq_routing(struct kvm *kvm) -{ - return kvm_set_irq_routing(kvm, empty_routing, 0, 0); -} - void kvm_arch_post_irq_routing_update(struct kvm *kvm) { if (!irqchip_split(kvm)) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 082ac6d95a3a..a5c8caed76b1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6552,9 +6552,6 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, goto split_irqchip_unlock; if (kvm->created_vcpus) goto split_irqchip_unlock; - r = kvm_setup_empty_irq_routing(kvm); - if (r) - goto split_irqchip_unlock; /* Pairs with irqchip_in_kernel. */ smp_wmb(); kvm->arch.irqchip_mode = KVM_IRQCHIP_SPLIT; |