On 3/05/2024 12:21 pm, Edgecombe, Rick P wrote:
On Sat, 2024-03-02 at 00:20 +1300, Kai Huang wrote:
KVM will need to read a bunch of non-TDMR related metadata to create and
run TDX guests. Export the metadata read infrastructure for KVM to use.
Specifically, export two helpers:
1) The helper which reads multiple metadata fields to a buffer of a
structure based on the "field ID -> structure member" mapping table.
2) The low level helper which just reads a given field ID.
Could 2 be a static inline in a helper, and then only have one export?
I assume you were thinking about making 2) call the 1), so we don't need
to export 2).
This is not feasible due to:
a). 1) must 'struct tdx_metadata_field_mapping' table as input, and for
that we need to ues the TDX_SYSINFO_MAP() macro to define a structure
for just one 'u64' and define a 'struct tdx_metadata_field_mapping'
table which only has one element for that.
b). TDX_SYSINFO_MAP() macro actually doesn't support taking a metadata
field "variable", but can only support using the name of the metadata field.
However we can try to make 1) as a wrapper of 2). But this would
require some change to the patch 4.
I'll reply separately to patch 4 and you can take a look whether that is
better.
