Now that we have a cache of MSI->LPI translations, it is pretty
easy to implement kvm_arch_set_irq_inatomic (this cache can be
parsed without sleeping).
Hopefully, this will improve some LPI-heavy workloads.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
virt/kvm/arm/vgic/vgic-irqfd.c | 36 ++++++++++++++++++++++++++++------
1 file changed, 30 insertions(+), 6 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-irqfd.c b/virt/kvm/arm/vgic/vgic-irqfd.c
index 99e026d2dade..9f203ed8c8f3 100644
--- a/virt/kvm/arm/vgic/vgic-irqfd.c
+++ b/virt/kvm/arm/vgic/vgic-irqfd.c
@@ -77,6 +77,15 @@ int kvm_set_routing_entry(struct kvm *kvm,
return r;
}
+static void kvm_populate_msi(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm_msi *msi)
+{
+ msi->address_lo = e->msi.address_lo;
+ msi->address_hi = e->msi.address_hi;
+ msi->data = e->msi.data;
+ msi->flags = e->msi.flags;
+ msi->devid = e->msi.devid;
+}
/**
* kvm_set_msi: inject the MSI corresponding to the
* MSI routing entry
@@ -90,21 +99,36 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
{
struct kvm_msi msi;
- msi.address_lo = e->msi.address_lo;
- msi.address_hi = e->msi.address_hi;
- msi.data = e->msi.data;
- msi.flags = e->msi.flags;
- msi.devid = e->msi.devid;
-
if (!vgic_has_its(kvm))
return -ENODEV;
if (!level)
return -1;
+ kvm_populate_msi(e, &msi);
return vgic_its_inject_msi(kvm, &msi);
}
+/**
+ * kvm_arch_set_irq_inatomic: fast-path for irqfd injection
+ *
+ * Currently only direct MSI injecton is supported.
+ */
+int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm, int irq_source_id, int level,
+ bool line_status)
+{
+ if (e->type == KVM_IRQ_ROUTING_MSI && vgic_has_its(kvm) && level) {
+ struct kvm_msi msi;
+
+ kvm_populate_msi(e, &msi);
+ if (!vgic_its_inject_cached_translation(kvm, &msi))
+ return 0;
+ }
+
+ return -EWOULDBLOCK;
+}
+
int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)
{
struct kvm_irq_routing_entry *entries;
--
2.20.1
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