pci: add config operations callbacks on the PCI header
When implementing PCI device passthrough, we will need to forward config
accesses from a guest to the VFIO driver. Add a private cfg_ops structure
to the PCI header, and use it in the PCI config access functions.
A read from the guest first calls into the device's cfg_ops.read, to let
the backend update the local header before filling the guest register.
Same happens for a write, we let the backend perform the write and replace
the guest-provided register with whatever sticks, before updating the local
header.
Try to untangle the PCI config access logic while we're at it.
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[JPB: moved to a separate patch]
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2 files changed
