On Fri, Apr 9, 2021 at 3:39 PM Jason Wang <jasow...@redhat.com> wrote:
>
>
> 在 2021/4/8 下午5:38, Cindy Lu 写道:
> > Add support for configure interrupt, use kvm_irqfd_assign and set the
> > gsi to kernel. When the configure notifier was eventfd_signal by host
> > kernel, this will finally inject an msix interrupt to guest
> >
> > Signed-off-by: Cindy Lu <l...@redhat.com>
> > ---
> > hw/virtio/virtio-pci.c | 91 ++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 88 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index 481f6e7505..7b02f42c06 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -664,7 +664,6 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev,
> > }
> >
> > static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
> > - unsigned int queue_no,
> > unsigned int vector)
> > {
> > VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
> > @@ -726,7 +725,7 @@ static int kvm_virtio_pci_vector_use(VirtIOPCIProxy
> > *proxy, int nvqs)
> > if (vector >= msix_nr_vectors_allocated(dev)) {
> > continue;
> > }
> > - ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector);
> > + ret = kvm_virtio_pci_vq_vector_use(proxy, vector);
> > if (ret < 0) {
> > goto undo;
> > }
> > @@ -760,6 +759,56 @@ undo:
> > }
> > return ret;
> > }
> > +static int kvm_virtio_pci_vector_config_use(VirtIOPCIProxy *proxy)
> > +{
> > + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> > + unsigned int vector;
> > + int ret;
> > + EventNotifier *n = virtio_get_config_notifier(vdev);
> > + vector = vdev->config_vector ;
> > + ret = kvm_virtio_pci_vq_vector_use(proxy, vector);
> > + if (ret < 0) {
> > + goto undo;
> > + }
> > + ret = kvm_virtio_pci_irqfd_use(proxy, n, vector);
>
>
> So the kvm_virtio_pci_vector_use() has the following codes:
>
> /* If guest supports masking, set up irqfd now.
> * Otherwise, delay until unmasked in the frontend.
> */
> if (vdev->use_guest_notifier_mask && k->guest_notifier_mask) {
> vq = virtio_get_queue(vdev, queue_no);
> n = virtio_queue_get_guest_notifier(vq);
> ret = kvm_virtio_pci_irqfd_use(proxy, n, vector);
> if (ret < 0) {
> kvm_virtio_pci_vq_vector_release(proxy, vector);
> goto undo;
> }
> }
>
> Do we need to check the masking support here as well?
>
> Btw, I think we can factor out the core logic (decouple the queue_no) of
> kvm_virtio_pci_vector_user() and let it be reused by config interrupt.
>
sure , I will rewrite this part
>
> > + if (ret < 0) {
> > + goto undo;
> > + }
> > + return 0;
> > +undo:
> > + kvm_virtio_pci_irqfd_release(proxy, n, vector);
> > + return ret;
> > +}
> > +static void kvm_virtio_pci_vector_config_release(VirtIOPCIProxy *proxy)
> > +{
> > + PCIDevice *dev = &proxy->pci_dev;
> > + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> > + unsigned int vector;
> > + EventNotifier *n = virtio_get_config_notifier(vdev);
> > + vector = vdev->config_vector ;
> > + if (vector >= msix_nr_vectors_allocated(dev)) {
> > + return;
> > + }
> > + kvm_virtio_pci_irqfd_release(proxy, n, vector);
> > + kvm_virtio_pci_vq_vector_release(proxy, vector);
> > +}
> > +static int virtio_pci_set_config_notifier(DeviceState *d, bool assign)
> > +{
> > + VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
> > + VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> > + EventNotifier *notifier = virtio_get_config_notifier(vdev);
> > + int r = 0;
> > + if (assign) {
> > + r = event_notifier_init(notifier, 0);
> > + virtio_set_config_notifier_fd_handler(vdev, true, true);
> > + kvm_virtio_pci_vector_config_use(proxy);
> > + } else {
> > + virtio_set_config_notifier_fd_handler(vdev, false, true);
>
>
> So let's try to unify the codes between this and
> virtio_queue_set_guest_notifier_fd_handler(). Bascailly it's just
> decouple virtqueue *.
>
sure will fix this
>
> > + kvm_virtio_pci_vector_config_release(proxy);
> > + event_notifier_cleanup(notifier);
> > + }
> > + return r;
> > +}
> >
> > static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs)
> > {
> > @@ -858,6 +907,14 @@ static int virtio_pci_vector_unmask(PCIDevice *dev,
> > unsigned vector,
> > EventNotifier *n;
> > int ret, index, unmasked = 0;
> >
> > + if (vdev->use_config_notifier == true) {
> > + n = virtio_get_config_notifier(vdev);
> > + ret = virtio_pci_vq_vector_unmask(proxy, 0, vector, msg,
> > + VIRTIO_CONFIG_VECTOR, n);
> > + if (ret < 0) {
> > + goto config_undo;
> > + }
> > + }
> > while (vq) {
> > index = virtio_get_queue_index(vq);
> > if (!virtio_queue_get_num(vdev, index)) {
> > @@ -889,6 +946,10 @@ undo:
> > }
> > vq = virtio_vector_next_queue(vq);
> > }
> > + config_undo:
> > + n = virtio_get_config_notifier(vdev);
> > + virtio_pci_vq_vector_mask(proxy, 0, vector,
> > + VIRTIO_CONFIG_VECTOR, n);
> > return ret;
> > }
> >
> > @@ -900,6 +961,10 @@ static void virtio_pci_vector_mask(PCIDevice *dev,
> > unsigned vector)
> > EventNotifier *n;
> > int index;
> >
> > + if (vdev->use_config_notifier == true) {
>
>
> Is this sufficient to know the vector is used by config interrupt?
>
>
> > + n = virtio_get_config_notifier(vdev);
> > + virtio_pci_vq_vector_mask(proxy, 0, vector, VIRTIO_CONFIG_VECTOR,
> > n);
> > + }
> > while (vq) {
> > index = virtio_get_queue_index(vq);
> > n = virtio_queue_get_guest_notifier(vq);
> > @@ -945,6 +1010,21 @@ static void virtio_pci_vector_poll(PCIDevice *dev,
> > msix_set_pending(dev, vector);
> > }
> > }
> > + if (vdev->use_config_notifier == true) {
> > + vector = vdev->config_vector;
> > + notifier = virtio_get_config_notifier(vdev);
> > + if (vector < vector_start || vector >= vector_end ||
> > + !msix_is_masked(dev, vector)) {
> > + return;
> > + }
> > + if (k->guest_notifier_pending) {
> > + if (k->guest_notifier_pending(vdev, 0, VIRTIO_CONFIG_VECTOR))
> > {
> > + msix_set_pending(dev, vector);
> > + }
> > + } else if (event_notifier_test_and_clear(notifier)) {
> > + msix_set_pending(dev, vector);
> > + }
> > + }
>
>
> Let's unify the code here with the code that deal with vq vectors in the
> loop above.
>
> Thanks
>
>
> > }
> >
> > static int virtio_pci_set_guest_notifier(DeviceState *d, int n, bool
> > assign,
> > @@ -1032,6 +1112,10 @@ static int
> > virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign)
> > goto assign_error;
> > }
> > }
> > + r = virtio_pci_set_config_notifier(d, assign);
> > + if (r < 0) {
> > + goto config_error;
> > + }
> > r = msix_set_vector_notifiers(&proxy->pci_dev,
> > virtio_pci_vector_unmask,
> > virtio_pci_vector_mask,
> > @@ -1048,7 +1132,8 @@ notifiers_error:
> > assert(assign);
> > kvm_virtio_pci_vector_release(proxy, nvqs);
> > }
> > -
> > + config_error:
> > + kvm_virtio_pci_vector_config_release(proxy);
> > assign_error:
> > /* We get here on assignment failure. Recover by undoing for VQs 0 ..
> > n. */
> > assert(assign);
>
