return ret;
}
-static int vfio_msix_vector_use(PCIDevice *pdev,
- unsigned int nr, MSIMessage msg)
+static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
+ MSIMessage *msg, IOHandler *handler)
{
VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
VFIOMSIVector *vector;
* Attempt to enable route through KVM irqchip,
* default to userspace handling if unavailable.
*/
- vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
+ vector->virq = msg ? kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
if (vector->virq < 0 ||
kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
vector->virq) < 0) {
vector->virq = -1;
}
qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
- vfio_msi_interrupt, NULL, vector);
+ handler, NULL, vector);
}
/*
return 0;
}
+static int vfio_msix_vector_use(PCIDevice *pdev,
+ unsigned int nr, MSIMessage msg)
+{
+ return vfio_msix_vector_do_use(pdev, nr, &msg, vfio_msi_interrupt);
+}
+
static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
{
VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
vdev->interrupt = VFIO_INT_MSIX;
+ /*
+ * Some communication channels between VF & PF or PF & fw rely on the
+ * physical state of the device and expect that enabling MSI-X from the
+ * guest enables the same on the host. When our guest is Linux, the
+ * guest driver call to pci_enable_msix() sets the enabling bit in the
+ * MSI-X capability, but leaves the vector table masked. We therefore
+ * can't rely on a vector_use callback (from request_irq() in the guest)
+ * to switch the physical device into MSI-X mode because that may come a
+ * long time after pci_enable_msix(). This code enables vector 0 with
+ * triggering to userspace, then immediately release the vector, leaving
+ * the physical device with no vectors enabled, but MSI-X enabled, just
+ * like the guest view.
+ */
+ vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL);
+ vfio_msix_vector_release(&vdev->pdev, 0);
+
if (msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use,
vfio_msix_vector_release, NULL)) {
error_report("vfio: msix_set_vector_notifiers failed\n");