[PATCH v8 06/16] PCI: Only allocate IRQ routing entry when available
From: andre.przywara@arm.com (Andre Przywara)
Date: 2016-11-04 17:31:53
Also in:
kvm, kvmarm
Subsystem:
the rest · Maintainer:
Linus Torvalds
If we need to inject an MSI into the guest, we rely at the moment on a working GSI MSI routing functionality. However we can get away without IRQ routing, if the host supports MSI injection via the KVM_SIGNAL_MSI ioctl. So we try the GSI routing first, but if that fails due to a missing IRQ routing functionality, we fall back to KVM_SIGNAL_MSI (if that is supported). Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- virtio/pci.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/virtio/pci.c b/virtio/pci.c
index b3b4aac..604b9ec 100644
--- a/virtio/pci.c
+++ b/virtio/pci.c@@ -193,8 +193,14 @@ static bool virtio_pci__specific_io_out(struct kvm *kvm, struct virtio_device *v gsi = irq__add_msix_route(kvm, &vpci->msix_table[vec].msg); - if (gsi >= 0) + if (gsi >= 0) { vpci->config_gsi = gsi; + break; + } + if (gsi == -ENXIO && + vpci->features & VIRTIO_PCI_F_SIGNAL_MSI) + break; + die("failed to configure MSIs"); break; case VIRTIO_MSI_QUEUE_VECTOR: vec = ioport__read16(data);
@@ -205,8 +211,14 @@ static bool virtio_pci__specific_io_out(struct kvm *kvm, struct virtio_device *v gsi = irq__add_msix_route(kvm, &vpci->msix_table[vec].msg); - if (gsi < 0) + if (gsi < 0) { + if (gsi == -ENXIO && + vpci->features & VIRTIO_PCI_F_SIGNAL_MSI) + break; + + die("failed to configure MSIs"); break; + } vpci->gsis[vpci->queue_selector] = gsi; if (vdev->ops->notify_vq_gsi) vdev->ops->notify_vq_gsi(kvm, vpci->dev,
--
2.9.0