Re: [PATCH v6 7/9] virtio-pci: add support for configure interrupt

[Jason Wang]

在 2021/4/27 上午11:39, 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
> ---
>   hw/virtio/virtio-pci.c | 186 ++++++++++++++++++++++++++---------------
>   1 file changed, 120 insertions(+), 66 deletions(-)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 2b7e6cc0d9..07d28dd367 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -664,12 +664,10 @@ 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];
>       int ret;
> -


Unnecessary changes.


>       if (irqfd->users == 0) {
>           ret = kvm_irqchip_add_msi_route(kvm_state, vector, &proxy->pci_dev);
>           if (ret < 0) {
> @@ -708,93 +706,120 @@ static void kvm_virtio_pci_irqfd_release(VirtIOPCIProxy 
> *proxy,
>       ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, irqfd->virq);
>       assert(ret == 0);
>   }
> -


So did here.


> -static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
> + static int virtio_pci_get_notifier(VirtIOPCIProxy *proxy, int queue_no,
> +                                      EventNotifier **n, unsigned int *vector)


The indentation looks not correct.


>   {
>       PCIDevice *dev = &proxy->pci_dev;
>       VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> -    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
> -    unsigned int vector;
> -    int ret, queue_no;
>       VirtQueue *vq;
> -    EventNotifier *n;
> -    for (queue_no = 0; queue_no < nvqs; queue_no++) {
> +
> +    if (queue_no == -1) {
> +        *n = virtio_get_config_notifier(vdev);
> +        *vector = vdev->config_vector;
> +    } else {
>           if (!virtio_queue_get_num(vdev, queue_no)) {
> -            break;
> -        }
> -        vector = virtio_queue_vector(vdev, queue_no);
> -        if (vector >= msix_nr_vectors_allocated(dev)) {
> -            continue;
> -        }
> -        ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector);
> -        if (ret < 0) {
> -            goto undo;
> -        }
> -        /* 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;
> -            }
> +            return -1;
>           }
> +        *vector = virtio_queue_vector(vdev, queue_no);
> +        vq = virtio_get_queue(vdev, queue_no);
> +        *n = virtio_queue_get_guest_notifier(vq);
> +    }
> +    if (*vector >= msix_nr_vectors_allocated(dev)) {
> +        return -1;
>       }
>       return 0;
> +}
>   
> +static int kvm_virtio_pci_vector_use_one(VirtIOPCIProxy *proxy, int queue_no)
> +{


Let's use separate patch for the introducing of 
kvm_virtio_pci_vector_user/release_one().

And then do the config interrupt support on top.

Thanks