After the virtio-blk device support has been introduced in the
previous commit, the vmm need to rely on this new device to boot
from disk images instead of initrd built into the kernel.
In order to achieve the proper support of virtio-blk, this commit
had to handle a few things:
- Register an ioevent fd for each virtqueue. This important to be
notified from the virtio driver that something has been written
on the queue.
- Fix the retrieval of 64bits BAR address. This is needed to provide
the right address which need to be registered as the notification
address from the virtio driver.
- Fix the write_bar and read_bar functions. They were both assuming
to be provided with an address, from which they were trying to
find the associated offset. But the reality is that the offset is
directly provided by the Bus layer.
- Register a new virtio-blk device as a virtio-pci device from the
vm.rs code. When the VM is started, it expects a block device to
be created, using this block device as the VM rootfs.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Copied from crosvm 107edb3e with one main modification: VirtioPciDevice
implements BusDevice.
We need this modification because it is the only way for us to be able
to add a VirtioPciDevice to the MMIO bus. Bus insertion takes a
BusDevice. The fact that VirtioPciDevice implements PciDevice which
itself implements BusDevice does not mean that Rust will automatically
downcast a VirtioPciDevice into a BusDevice.
crosvm works around that issue by having the PCI, virtio and BusDevice
implementations in the same crate.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Copied from Firecracker 17a9089d for the queue implementation and from
crosvm 107edb3e for the device Trait. The device trait has some PCI
specific methods hence its crosvm origin.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
