Add a new function to setup empty irq routing in kvm path, which
can be invoded in non-architecture-specific functions. The difference
compared to the kvm_setup_empty_irq_routing() is this function just
alloc the empty irq routing and does not need synchronize srcu, as
we will call it in kvm_create_vm().
This patch is a preparatory step for an upcoming patch to avoid
delay in KVM_CAP_SPLIT_IRQCHIP ioctl.
Signed-off-by: Yi Wang <foxywang@xxxxxxxxxxx>
---
include/linux/kvm_host.h | 1 +
virt/kvm/irqchip.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4944136efaa2..e91525c0a4ea 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2000,6 +2000,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
const struct kvm_irq_routing_entry *entries,
unsigned nr,
unsigned flags);
+int kvm_setup_empty_irq_routing_lockless(struct kvm *kvm);
int kvm_set_routing_entry(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue);
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 1e567d1f6d3d..90fc43bd0fe4 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -237,3 +237,22 @@ int kvm_set_irq_routing(struct kvm *kvm,
return r;
}
+
+int kvm_setup_empty_irq_routing_lockless(struct kvm *kvm)
+{
+ struct kvm_irq_routing_table *new;
+ u32 i, j;
+
+ new = kzalloc(struct_size(new, map, 1), GFP_KERNEL_ACCOUNT);
+ if (!new)
+ return -ENOMEM;
+
+ new->nr_rt_entries = 1;
+ for (i = 0; i < KVM_NR_IRQCHIPS; i++)
+ for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
+ new->chip[i][j] = -1;
+
+ RCU_INIT_POINTER(kvm->irq_routing, new);
+
+ return 0;
+}
--
2.39.3
