Re: [PATCH v3 3/8] Ovmf/HardwareInfoLib: Add Dxe lib to dynamically parse heterogenous data

["Gerd Hoffmann" <kraxel@redhat.com>]

On Tue, Jan 25, 2022 at 03:30:10PM +0100, Nicolas Ojeda Leon wrote:
> Following the Hardware Info library, create the DxeHardwareInfoLib
> which implements the whole API capable of parsing heterogeneous hardware
> information. The list-like API grants callers a flexible and common
> pattern to retrieve the data. Moreover, the initial source is a BLOB
> which generalizes the host-to-guest transmission mechanism.
> 
> The Hardware Info library main objective is to provide a way to
> describe non-discoverable hardware so that the host can share the
> available resources with the guest in Ovmf platforms. This change
> features and embraces the main idea behind the library by providing
> an API that parses a BLOB into a linked list to retrieve hardware
> data from any source. Additionally, list-like APIs are provided so
> that the hardware info list can be traversed conveniently.
> Similarly, the capability is provided to filter results by specific
> hardware types. However, heterogeneous elements can be added to the
> list, increasing the flexibility. This way, a single source, for
> example a fw-cfg file, can be used to describe several instances of
> multiple types of hardware.
> 
> This part of the Hardware Info library makes use of dynamic memory
> and is intended for stages in which memory services are available.
> A motivation example is the PciHostBridgeLib. This library, part
> of the PCI driver populates the list of PCI root bridges during DXE
> stage for future steps to discover the resources under them. The
> hardware info library can be used to obtain the detailed description
> of available host bridges, for instance in the form of a fw-cfg file,
> and parse that information into a dynmaic list that allows, first to
> verify consistency of the data, and second discover the resources
> availabe for each root bridge.
> 
> Cc: Alexander Graf <graf@amazon.de>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> 
> Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com>

Acked-by: Gerd Hoffmann <kraxel@redhat.com>