Implement KVM_PRE_FAULT_MEMORY on s390, and update documentation and
selftests accordingly.
Faulted-in pages will be marked as accessed, unlike x86, otherwise they
will trigger a minor fault when accessed. Avoiding such faults is one of
the points of KVM_PRE_FAULT_MEMORY.
This series depends on some kvm/s390 functions that are slightly buggy
at the moment. Those functions are being fixed in a separate series.
Even without those fixes, this series is not buggy, it's just a bit
inefficient in some corner cases.
CCing x86 people due to changes in the documentation and the selftests
just for completeness, since the selftest has been acked already.
v2->v3:
* Fix typos
* Correctly indicate page size in gmap_handle_minor_crste_fault() also
in case nothing needed to be done.
* Pick up and acked-by
v1->v2:
* Add the crste_region3 flag in struct guest_fault to keep track of the
page size used to solve a fault.
* Rewrite the s390 version of kvm_arch_vcpu_pre_fault_memory() so it
looks and behaves similarly to the x86 version. No more loops, better
handling of hugepage mappings, and more correct error handling.
* Remove the assertion vcpu->run->exit_reason == KVM_EXIT_IO from the
selftest, as it is redundant and x86-specific.
Claudio Imbrenda (5):
KVM: s390: Track page size in struct guest_fault
KVM: s390: Implement KVM_PRE_FAULT_MEMORY
KVM: s390: Update KVM_PRE_FAULT_MEMORY API documentation
KVM: selftests: Fix pre_fault_memory_test to run on s390
KVM: selftests: Enable pre_fault_memory_test for s390
Documentation/virt/kvm/api.rst | 5 ++-
arch/s390/kvm/Kconfig | 1 +
arch/s390/kvm/dat.h | 1 +
arch/s390/kvm/gmap.c | 2 +
arch/s390/kvm/kvm-s390.c | 45 +++++++++++++++++++
tools/testing/selftests/kvm/Makefile.kvm | 1 +
.../selftests/kvm/pre_fault_memory_test.c | 7 +--
7 files changed, 54 insertions(+), 8 deletions(-)
--
2.54.0