Update 'test-guest-state-buffer.c' to add two new KUNIT test cases for
validating correctness of changes to Guest-state-buffer management
infrastructure for adding support for Hostwide GSB elements.
The newly introduced test test_gs_hostwide_msg() checks if the Hostwide
elements can be set and parsed from a Guest-state-buffer. The second kunit
test test_gs_hostwide_counters() checks if the Hostwide GSB elements can be
send to the L0-PowerVM hypervisor via the H_GUEST_SET_STATE hcall and
ensures that the returned guest-state-buffer has all the 5 Hostwide stat
counters present.
Below is the KATP test report with the newly added KUNIT tests:
KTAP version 1
# Subtest: guest_state_buffer_test
# module: test_guest_state_buffer
1..7
ok 1 test_creating_buffer
ok 2 test_adding_element
ok 3 test_gs_bitmap
ok 4 test_gs_parsing
ok 5 test_gs_msg
ok 6 test_gs_hostwide_msg
# test_gs_hostwide_counters: Guest Heap Size=0 bytes
# test_gs_hostwide_counters: Guest Heap Size Max=10995367936 bytes
# test_gs_hostwide_counters: Guest Page-table Size=2178304 bytes
# test_gs_hostwide_counters: Guest Page-table Size Max=2147483648 bytes
# test_gs_hostwide_counters: Guest Page-table Reclaim Size=0 bytes
ok 7 test_gs_hostwide_counters
# guest_state_buffer_test: pass:7 fail:0 skip:0 total:7
# Totals: pass:7 fail:0 skip:0 total:7
ok 1 guest_state_buffer_test
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416162740.93143-4-vaibhav@linux.ibm.com
With ARCH=powerpc, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/test-guest-state-buffer.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/kvm-pr.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/kvm-hv.o
Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
[mpe: Change kvm-hv description to mention POWER8 & later]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240615-md-powerpc-arch-powerpc-kvm-v1-1-7478648b3100@quicinc.com
Add support for using DPDES in the library for using guest state
buffers. DPDES support is needed for enabling usage of doorbells in a L2
KVM on PAPR guest.
Fixes: 6ccbbc33f0 ("KVM: PPC: Add helper library for Guest State Buffers")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240605113913.83715-2-gautam@linux.ibm.com
The PAPR "Nestedv2" guest API introduces the concept of a Guest State
Buffer for communication about L2 guests between L1 and L0 hosts.
In the new API, the L0 manages the L2 on behalf of the L1. This means
that if the L1 needs to change L2 state (e.g. GPRs, SPRs, partition
table...), it must request the L0 perform the modification. If the
nested host needs to read L2 state likewise this request must
go through the L0.
The Guest State Buffer is a Type-Length-Value style data format defined
in the PAPR which assigns all relevant partition state a unique
identity. Unlike a typical TLV format the length is redundant as the
length of each identity is fixed but is included for checking
correctness.
A guest state buffer consists of an element count followed by a stream
of elements, where elements are composed of an ID number, data length,
then the data:
Header:
<---4 bytes--->
+----------------+-----
| Element Count | Elements...
+----------------+-----
Element:
<----2 bytes---> <-2 bytes-> <-Length bytes->
+----------------+-----------+----------------+
| Guest State ID | Length | Data |
+----------------+-----------+----------------+
Guest State IDs have other attributes defined in the PAPR such as
whether they are per thread or per guest, or read-only.
Introduce a library for using guest state buffers. This includes support
for actions such as creating buffers, adding elements to buffers,
reading the value of elements and parsing buffers. This will be used
later by the nestedv2 guest support.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230914030600.16993-9-jniethe5@gmail.com
