[PATCH v2 0/4] KVM: selftests: Introduce VM_MODE_PXXV48_4K

Peter Xu
2019-08-29T02:21:35Z

v2:
- pick r-bs
- rebased to master
- fix pa width detect, check cpuid(1):edx.PAE(bit 6)
- fix arm compilation issue [Drew]
- fix indents issues and ways to define macros [Drew]
- provide functions for fetching cpu pa/va bits [Drew]

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.

[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 | 79 +++++--------------
.../testing/selftests/kvm/include/kvm_util.h | 16 +++-
.../selftests/kvm/include/x86_64/processor.h | 3 +
.../selftests/kvm/lib/aarch64/processor.c | 3 +
tools/testing/selftests/kvm/lib/kvm_util.c | 67 ++++++++++++----
.../selftests/kvm/lib/x86_64/processor.c | 30 ++++++-
6 files changed, 119 insertions(+), 79 deletions(-)

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2.21.0