The work is based on Thomas's s390 port for dirty_log_test. This series originates from "[PATCH] KVM: selftests: Detect max PA width from cpuid" [1] and one of Drew's comments - instead of keeping the hackish line to overwrite guest_pa_bits all the time, this series introduced the new mode VM_MODE_PXXV48_4K for x86_64 platform. The major issue is that even all the x86_64 kvm selftests are currently using the guest mode VM_MODE_P52V48_4K, many x86_64 hosts are not using 52 bits PA (and in most cases, far less). If with luck we could be having 48 bits hosts, but it's more adhoc (I've observed 3 x86_64 systems, they are having different PA width of 36, 39, 48). I am not sure whether this is happening to the other archs as well, but it probably makes sense to bring the x86_64 tests to the real world on always using the correct PA bits. A side effect of this series is that it will also fix the crash we've encountered on Xeon E3-1220 as mentioned [1] due to the differenciation of PA width. With [1], we've observed AMD host issues when with NPT=off. However a funny fact is that after I reworked into this series, the tests can instead pass on both NPT=on/off. It could be that the series changes vm->pa_bits or other fields so something was affected. I didn't dig more on that though, considering we should not lose anything. Any kind of smoke test would be greatly welcomed (especially on s390 or ARM). Same to comments. Thanks, [1] https://lkml.org/lkml/2019/8/26/141 Peter Xu (4): KVM: selftests: Move vm type into _vm_create() internally KVM: selftests: Create VM earlier for dirty log test KVM: selftests: Introduce VM_MODE_PXXV48_4K KVM: selftests: Remove duplicate guest mode handling tools/testing/selftests/kvm/dirty_log_test.c | 78 +++++-------------- .../testing/selftests/kvm/include/kvm_util.h | 17 +++- .../selftests/kvm/lib/aarch64/processor.c | 3 + tools/testing/selftests/kvm/lib/kvm_util.c | 77 ++++++++++++++---- .../selftests/kvm/lib/x86_64/processor.c | 8 +- 5 files changed, 107 insertions(+), 76 deletions(-) -- 2.21.0
