kvm powerpc/book3s-apiv2: Add support for Hostwide GSB elements

Add support for adding and parsing Hostwide elements to the
Guest-state-buffer data structure used in apiv2. These elements are used to
share meta-information pertaining to entire L1-Lpar and this
meta-information is maintained by L0-PowerVM hypervisor. Example of this
include the amount of the page-table memory currently used by L0-PowerVM
for hosting the Shadow-Pagetable of all active L2-Guests. More of the are
documented in kernel-documentation at [1]. The Hostwide GSB elements are
currently only support with H_GUEST_SET_STATE hcall with a special flag
namely 'KVMPPC_GS_FLAGS_HOST_WIDE'.

The patch introduces new defs for the 5 new Hostwide GSB elements including
their GSIDs as well as introduces a new class of GSB elements namely
'KVMPPC_GS_CLASS_HOSTWIDE' to indicate to GSB construction/parsing
infrastructure in 'kvm/guest-state-buffer.c'. Also
gs_msg_ops_vcpu_get_size(), kvmppc_gsid_type() and
kvmppc_gse_{flatten,unflatten}_iden() are updated to appropriately indicate
the needed size for these Hostwide GSB elements as well as how to
flatten/unflatten their GSIDs so that they can be marked as available in
GSB bitmap.

[1] Documention/arch/powerpc/kvm-nested.rst

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416162740.93143-3-vaibhav@linux.ibm.com

0 files changed, 0 insertions, 0 deletions