Re: [PATCH v10 00/10]vhost-vdpa: add support for configure interrupt

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Nov 05, 2021 at 12:48:17AM +0800, Cindy Lu wrote:
> these patches add the support for configure interrupt
> 
> These codes are all tested in vp-vdpa (support configure interrupt)
> vdpa_sim (not support configure interrupt), virtio tap device
> 
> test in virtio-pci bus and virtio-mmio bus
> 
> Change in v2:
> Add support for virtio-mmio bus
> active the notifier while the backend support configure interrupt
> misc fixes from v1
> 
> Change in v3
> fix the coding style problems
> 
> Change in v4
> misc fixes from v3
> merge the set_config_notifier to set_guest_notifier
> when vdpa start, check the feature by VIRTIO_NET_F_STATUS
> 
> Change in v5
> misc fixes from v4
> split the code to introduce configure interrupt type and the callback function
> will init the configure interrupt in all virtio-pci and virtio-mmio bus, but will
> only active while using vhost-vdpa driver
> 
> Change in v6
> misc fixes from v5
> decouple vq from interrupt setting and misc process
> fix the bug in virtio_net_handle_rx
> use -1 as the queue number to identify if the interrupt is configure interrupt
> 
> Change in v7
> misc fixes from v6
> decouple vq from interrupt setting and misc process
> decouple vq from vector use/release process
> decouple vq from set notifier fd handler process
> move config_notifier and masked_config_notifier to VirtIODevice
> fix the bug in virtio_net_handle_rx, add more information
> add VIRTIO_CONFIG_IRQ_IDX as the queue number to identify if the interrupt is configure interrupt
> 
> Change in v8
> misc fixes from v7
> decouple vq from interrupt setting and misc process
> decouple vq from vector use/release process
> decouple vq from set notifier fd handler process
> move the vhost configure interrupt to vhost_net
> 
> Change in v9
> misc fixes from v8
> address the comments from v8
> 
> Change in v10
> fix the hang issue in qtest
> address the comments from v9
> 
> Cindy Lu (10):
>   virtio: introduce macro IRTIO_CONFIG_IRQ_IDX
>   virtio-pci: decouple notifier from interrupt process
>   virtio-pci: decouple the single vector from the interrupt process
>   vhost: introduce new VhostOps vhost_set_config_call
>   vhost-vdpa: add support for config interrupt
>   virtio: add support for configure interrupt
>   vhost: add support for configure interrupt
>   virtio-net: add support for configure interrupt
>   virtio-mmio: add support for configure interrupt
>   virtio-pci: add support for configure interrupt
> 
>  hw/display/vhost-user-gpu.c       |   6 +
>  hw/net/vhost_net.c                |   9 +
>  hw/net/virtio-net.c               |  10 +-
>  hw/virtio/trace-events            |   1 +
>  hw/virtio/vhost-user-fs.c         |   6 +
>  hw/virtio/vhost-vdpa.c            |   7 +
>  hw/virtio/vhost-vsock-common.c    |   6 +
>  hw/virtio/vhost.c                 |  76 +++++++++
>  hw/virtio/virtio-crypto.c         |   6 +
>  hw/virtio/virtio-mmio.c           |  27 +++
>  hw/virtio/virtio-pci.c            | 269 +++++++++++++++++++++---------
>  hw/virtio/virtio-pci.h            |   4 +-
>  hw/virtio/virtio.c                |  29 ++++
>  include/hw/virtio/vhost-backend.h |   3 +
>  include/hw/virtio/vhost.h         |   4 +
>  include/hw/virtio/virtio.h        |   7 +
>  include/net/vhost_net.h           |   2 +
>  17 files changed, 389 insertions(+), 83 deletions(-)

So I just realized something. The spec says:

The device MUST set the Device Configuration Interrupt bit
in \field{ISR status} before sending a device configuration
change notification to the driver.

and I don't see how these patches achieve this: it requires
that config interrupts go through userspace.

Revert, and think more about it? Or did I miss something?


> -- 
> 2.21.3