On Fri, 18 Oct 2019 18:55:02 +0800 Jason Wang jasowang@redhat.com wrote:
On 2019/10/18 下午5:46, Cornelia Huck wrote:
On Thu, 17 Oct 2019 18:48:34 +0800 Jason Wang jasowang@redhat.com wrote:
- @get_vendor_id: Get virtio vendor id
@mdev: mediated device
Returns u32: virtio vendor idHow is the vendor id defined? As for normal virtio-pci devices?
The vendor that provides this device. So something like this
I notice that MMIO also had this so it looks to me it's not pci specific.
Ok. Would be good to specify this more explicitly.
- @get_status: Get the device status
@mdev: mediated device
Returns u8: virtio device status
- @set_status: Set the device status
@mdev: mediated device
@status: virtio device status
- @get_config: Read from device specific configuration space
@mdev: mediated device
@offset: offset from the beginning of
configuration space
@buf: buffer used to read to
@len: the length to read from
configration space
- @set_config: Write to device specific configuration space
@mdev: mediated device
@offset: offset from the beginning of
configuration space
@buf: buffer used to write from
@len: the length to write to
configration space
- @get_mdev_features: Get the feature of virtio mdev device
@mdev: mediated device
Returns the mdev features (API) support by
the device.What kind of 'features' are supposed to go in there? Are these bits, like you defined for VIRTIO_MDEV_F_VERSION_1 above?
It's the API or mdev features other than virtio features. It could be used by driver to determine the capability of the mdev device. Besides _F_VERSION_1, we may add dirty page tracking etc which means we need new device ops.
Ok, so that's supposed to be distinct bits that can be or'ed together? Makes sense, but probably needs some more documentation somewhere.
- @get_generation: Get device generaton
@mdev: mediated device
Returns u32: device generationIs that callback mandatory?
I think so, it's hard to emulate that completely in virtio-mdev transport.
IIRC, the generation stuff is not mandatory in the current version of virtio, as not all transports have that concept.
Generally, are any of the callbacks optional, or are all of them mandatory? From what I understand, you plan to add new things that depend on features... would that mean non-mandatory callbacks?