On Tue, Sep 20, 2022 at 04:14:56AM +0000, Ricardo Koller wrote:
> This series adds a new aarch64 selftest for testing stage 2 fault handling for
> various combinations of guest accesses (e.g., write, S1PTW), backing sources
> (e.g., anon), and types of faults (e.g., read on hugetlbfs with a hole, write
> on a readonly memslot). Each test tries a different combination and then checks
> that the access results in the right behavior (e.g., uffd faults with the right
> address and write/read flag). Some interesting combinations are:
>
> - loading an instruction leads to a stage 1 page-table-walk that misses on
> stage 2 because the backing memslot for the page table it not in host memory
> (a hole was punched right there) and the fault is handled using userfaultfd.
> The expected behavior is that this leads to a userfaultfd fault marked as a
> write. See commit c4ad98e4b72c ("KVM: arm64: Assume write fault on S1PTW
> permission fault on instruction fetch") for why that's a write.
> - a cas (compare-and-swap) on a readonly memslot leads to a failed vcpu run.
> - write-faulting on a memslot that's marked for userfaultfd handling and dirty
> logging should result in a uffd fault and having the respective bit set in
> the dirty log.
>
> The first 8 commits of this series add library support. The first one adds a
> new userfaultfd library. Commits 2-5 add some misc library changes that will be
> used by the new test, like a library function to get the GPA of a PTE. Commits
> 6-8 breaks the implicit assumption that code and page tables live in memslot
> memslots should allocators use. This is then used by the new test to place the
> page tables in a specific memslot. The last 5 commits add the new selftest,
> one type of test at a time. It first adds core tests, then uffd, then dirty
> logging, then readonly memslots tests, and finally combinations of the previous
> ones (like uffd and dirty logging at the same time).
>
> v6 -> v7: https://lore.kernel.org/kvmarm/Yyi03sX5hx36M%2FZr@xxxxxxxxxx/
> - removed struct kvm_vm_mem_params. Changed page_fault_test.c accordingly. [Sean]
> - applied Oliver's patch to fix page_fault_test compilation warnings. [Oliver]
> - added R-b's from Oliver and Andrew. Didn't Andrew's R-b on 6/13 as the commit
> changed afterwards.
>
> v5 -> v6: https://lore.kernel.org/kvmarm/20220823234727.621535-1-ricarkol@xxxxxxxxxx/
> - added "enum memslot_type" and all the related cleanups due to it [Andrew]
> - default kvm_vm_mem_default with size=0 [Andrew,Sean]
> - __vm_vaddr_alloc() taking "enum memslot_type" and all the related cleanups
> due to this change [Andrew]
>
> v4 -> v5: https://lore.kernel.org/kvmarm/20220624213257.1504783-1-ricarkol@xxxxxxxxxx/
> - biggest change: followed suggestion from Sean and Andrew regarding a new
> arg for vm_create() to specify the guest memory layout. That's taken care
> of with these two new commits:
> KVM: selftests: Use the right memslot for code, page-tables, and data allocations
> KVM: selftests: Change ____vm_create() to take struct kvm_vm_mem_params
> plus the respective changes in the page_fault_test itself (mostly code reduction).
> - dropped some commits that are not needed after the above change:
> KVM: selftests: aarch64: Export _virt_pg_map with a pt_memslot arg
> KVM: selftests: Add vm_alloc_page_table_in_memslot library function
> KVM: selftests: Add vm_mem_region_get_src_fd library function
> - addressed Oliver comments in commit "KVM: selftests: aarch64: Add
> aarch64/page_fault_test"
> - collect r-b's from Andrew
>
> Ricardo Koller (13):
> KVM: selftests: Add a userfaultfd library
> KVM: selftests: aarch64: Add virt_get_pte_hva() library function
> KVM: selftests: Add missing close and munmap in
> __vm_mem_region_delete()
> KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h
> macros
> tools: Copy bitfield.h from the kernel sources
> KVM: selftests: Stash backing_src_type in struct userspace_mem_region
> KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_type
> KVM: selftests: Use the right memslot for code, page-tables, and data
> allocations
> KVM: selftests: aarch64: Add aarch64/page_fault_test
> KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test
> KVM: selftests: aarch64: Add dirty logging tests into page_fault_test
> KVM: selftests: aarch64: Add readonly memslot tests into
> page_fault_test
> KVM: selftests: aarch64: Add mix of tests into page_fault_test
>
> tools/include/linux/bitfield.h | 176 +++
> tools/testing/selftests/kvm/.gitignore | 1 +
> tools/testing/selftests/kvm/Makefile | 2 +
> .../selftests/kvm/aarch64/page_fault_test.c | 1116 +++++++++++++++++
> .../selftests/kvm/demand_paging_test.c | 228 +---
> .../selftests/kvm/include/aarch64/processor.h | 35 +-
> .../selftests/kvm/include/kvm_util_base.h | 29 +-
> .../selftests/kvm/include/userfaultfd_util.h | 45 +
> .../selftests/kvm/lib/aarch64/processor.c | 26 +-
> tools/testing/selftests/kvm/lib/elf.c | 3 +-
> tools/testing/selftests/kvm/lib/kvm_util.c | 82 +-
> .../selftests/kvm/lib/riscv/processor.c | 7 +-
> .../selftests/kvm/lib/s390x/processor.c | 7 +-
> .../selftests/kvm/lib/userfaultfd_util.c | 186 +++
> .../selftests/kvm/lib/x86_64/processor.c | 13 +-
> 15 files changed, 1698 insertions(+), 258 deletions(-)
> create mode 100644 tools/include/linux/bitfield.h
> create mode 100644 tools/testing/selftests/kvm/aarch64/page_fault_test.c
> create mode 100644 tools/testing/selftests/kvm/include/userfaultfd_util.h
> create mode 100644 tools/testing/selftests/kvm/lib/userfaultfd_util.c
>
> --
> 2.37.3.968.ga6b4b080e4-goog
>
Please ignore this v6 series (It should have been v7). Sending the real
v7 in a bit. Thanks and sorry for the mess!
