Hi all,
I am enclosing with this mail the specification document of
the PCI-SIG for Single Root I/O Virtualization.
I read the PCI SIG specification document for SR-IOV. The
document described about how any I/O request in a machine with SR-IOV coming
from the virtual machine bypasses the hypervisor and is handled directly by the
device. The document also describes a software layer in hypervisor known as
PCI-Manager which will configure the virtual functions to handle the I/O
requests of the VMs. The I/O requests of the virtual machines will be
processed faster as the hypervisor will not be involved during the
transactions.
But the document does not explain about how actually the I/O
requests are handled by the virtual functions in the device that are
responsible for handling the requests. Nor does it describe about the role of
the device drivers (which are present in the Dom0) during the I/O requests and
how I/O requests can happen without the involvement of the device drivers. Besides,
the actual data flow from domU’s to dom0 and the role of the PCIM during
data transfer is also unclear. Can anybody help us in understanding the same ?
Thanks and regards,
S.GURU
PRASAD