Hi Christian, Janosch, Heiko,
Here is a new version for the AR/MEM_OP issue I'm attempting to address,
with Heiko's feedback to v1.
Patch 1 performs the host/guest access register swap that Christian
suggested (instead of a full sync_reg/store_reg process).
Patch 2 provides a selftest patch that exercises this scenario.
Applying patch 2 without patch 1 fails in the following way:
[eric@host linux]# ./tools/testing/selftests/kvm/s390x/memop
TAP version 13
1..16
ok 1 simple copy
ok 2 generic error checks
ok 3 copy with storage keys
ok 4 cmpxchg with storage keys
ok 5 concurrently cmpxchg with storage keys
ok 6 copy with key storage protection override
ok 7 copy with key fetch protection
ok 8 copy with key fetch protection override
==== Test Assertion Failure ====
s390x/memop.c:186: !r
pid=5720 tid=5720 errno=4 - Interrupted system call
1 0x00000000010042af: memop_ioctl at memop.c:186 (discriminator 3)
2 0x0000000001006697: test_copy_access_register at memop.c:400 (discriminator 2)
3 0x0000000001002aaf: main at memop.c:1181
4 0x000003ffaec33a5b: ?? ??:0
5 0x000003ffaec33b5d: ?? ??:0
6 0x0000000001002ba9: _start at ??:?
KVM_S390_MEM_OP failed, rc: 40 errno: 4 (Interrupted system call)
Thoughts on this approach?
Thanks,
Eric
Changes:
v2:
[HC] Add a flag to indicate access registers have been loaded
v1: https://lore.kernel.org/r/20240209204539.4150550-1-farman@xxxxxxxxxxxxx/
[CB] Store access registers around memop ioctl
[JF] Add a kernel selftest
RFC: https://lore.kernel.org/r/20240131205832.2179029-1-farman@xxxxxxxxxxxxx/
Eric Farman (2):
KVM: s390: load guest access registers in MEM_OP ioctl
KVM: s390: selftests: memop: add a simple AR test
arch/s390/include/asm/kvm_host.h | 1 +
arch/s390/kvm/gaccess.c | 2 ++
arch/s390/kvm/kvm-s390.c | 11 +++++++++
tools/testing/selftests/kvm/s390x/memop.c | 28 +++++++++++++++++++++++
4 files changed, 42 insertions(+)
--
2.40.1
