Header Type is 8-bit. The bit 7 is used to identify a multi-function
device. The lower bit 1 and bit 0 are used to identify the header type.

   00b is defined for Normal devices
   01b is defined for PCI-to-PCI bridges
   10b is defined for PC Card Standard

Fix the check by masking the lower 2 bits only.

This patch fixes the device probe on VMware Workstation.

Signed-off-by: Asias He <asias@cloudius-systems.com>

Currently, only MSI-X is support in our PCI layer. Devices like AHCI
controller support MSI interrupt only. This paves the way for AHCI
driver.

Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add enum for PCI class/subclass.

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Add methods to get base_class and sub_class to find IDE device.

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

This would be useful for device with mmio bar, e.g. AHCI controller.

Signed-off-by: Asias He <asias@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Add Cloudius copyright and license statement to drivers/*.

A couple of header files were based on Linux's BSD-licensed header files
(e.g., include/uapi/linux/virtio_net.h) so they included the BSD license,
but not any copyright statement, so we can just replace that by our own
statement of the BSD license.

pci::pci_device is redundant, use pci::device.

of the pci virtio config size to a function using the first.

Created abstract base classes for device and drivers, changed the flow of driver loading / device probing