On 11/10/2019 10.56, Stefan Hajnoczi wrote:
> Implement the VIRTIO 1.0 virtio-pci interface. The main change here is
> that the register layout is no longer a fixed layout in BAR 0. Instead
> we have to iterate of PCI Capabilities to find descriptions of where
> various registers are located. The vring registers are also more
> fine-grained, allowing for more flexible vring layouts, but we don't
> take advantage of that.
>
> Note that test cases do not negotiate VIRTIO_F_VERSION_1 yet and are
> therefore not running in VIRTIO 1.0 mode.
>
> Signed-off-by: Stefan Hajnoczi <[email protected]>
> ---
> tests/Makefile.include | 1 +
> tests/libqos/virtio-pci-modern.h | 17 ++
> tests/libqos/virtio-pci.h | 10 +
> tests/libqos/virtio-pci-modern.c | 412 +++++++++++++++++++++++++++++++
> tests/libqos/virtio-pci.c | 6 +-
> 5 files changed, 445 insertions(+), 1 deletion(-)
> create mode 100644 tests/libqos/virtio-pci-modern.h
> create mode 100644 tests/libqos/virtio-pci-modern.c
[...]
> +static bool probe_device_type(QVirtioPCIDevice *dev)
> +{
> + uint16_t vendor_id;
> + uint16_t device_id;
> +
> + /* "Drivers MUST match devices with the PCI Vendor ID 0x1AF4" */
> + vendor_id = qpci_config_readw(dev->pdev, PCI_VENDOR_ID);
> + if (vendor_id != 0x1af4) {
> + return false;
> + }
> +
> + /*
> + * "Any PCI device with ... PCI Device ID 0x1000 through 0x107F inclusive
> + * is a virtio device"
> + */
> + device_id = qpci_config_readw(dev->pdev, PCI_DEVICE_ID);
> + if (device_id < 0x1000 || device_id > 0x107f) {
> + return false;
> + }
> +
> + /*
> + * "Devices MAY utilize a Transitional PCI Device ID range, 0x1000 to
> + * 0x103F depending on the device type"
> + */
> + if (device_id < 0x1040) {
> + /*
> + * "Transitional devices MUST have the PCI Subsystem Device ID
> matching
> + * the Virtio Device ID"
> + */
> + dev->vdev.device_type = qpci_config_readw(dev->pdev,
> PCI_SUBSYSTEM_ID);
Shouldn't you return "false" here in case the device_type is 0 ? Which
likely means that it is a legacy or broken device ...?
> + } else {
> + /*
> + * "The PCI Device ID is calculated by adding 0x1040 to the Virtio
> + * Device ID"
> + */
> + dev->vdev.device_type = device_id - 0x1040;
> + }
> +
> + return true;
> +}
Thomas
