vdpa/snet: implement the resume vDPA callback

The callback sends a resume command to the DPU through
the control mechanism.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230502131048.61134-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

vdpa/snet: use likely/unlikely macros in hot functions

- kick callback: most likely that the VQ is ready.
- interrupt handlers: most likely that the callback is not NULL.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230409120242.3460074-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vdpa/snet: implement kick_vq_with_data callback

Implement the kick_vq_with_data vDPA callback.
On kick, we pass the next available data to the DPU by writing it in
the kick offset.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230417083853.375076-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vdpa/snet: support the suspend vDPA callback

When suspend is called, the driver sends a suspend command to the DPU
through the control mechanism.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230413073337.31367-3-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

vdpa/snet: support getting and setting VQ state

This patch adds the get_vq_state and set_vq_state vDPA callbacks.

In order to get the VQ state, the state needs to be read from the DPU.
In order to allow that, the old messaging mechanism is replaced with a new,
flexible control mechanism.
This mechanism allows to read data from the DPU.

The mechanism can be used if the negotiated config version is 2 or
higher.

If the new mechanism is used when the config version is 1, it will call
snet_send_ctrl_msg_old, which is config 1 compatible.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20230413073337.31367-2-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

virtio: vdpa: new SolidNET DPU driver.

This commit includes:
1) The driver to manage the controlplane over vDPA bus.
2) A HW monitor device to read health values from the DPU.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230110165638.123745-4-alvaro.karsz@solid-run.com>
Message-Id: <20230209075128.78915-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>