kernel/linux.git/tools/testing/selftests/kvm, branch v5.13.1

KVM: selftests: Fix mapping length truncation in m{,un}map()

2021-06-24T08:04:38+00:00

max_mem_slots is now declared as uint32_t. The result of (0x200000 * 32767) is unexpectedly truncated to be 0xffe00000, whilst we actually need to allocate about, 63GB. Cast max_mem_slots to size_t in both mmap() and munmap() to fix the length truncation. We'll otherwise see the failure on arm64 thanks to the access_ok() checking in __kvm_set_memory_region(), as the unmapped VA happen to go beyond the task's allowed address space. # ./set_memory_region_test Allowed number of memory slots: 32767 Adding slots 0..32766, each memory region with 2048K size ==== Test Assertion Failure ==== set_memory_region_test.c:391: ret == 0 pid=94861 tid=94861 errno=22 - Invalid argument 1 0x00000000004015a7: test_add_max_memory_regions at set_memory_region_test.c:389 2 (inlined by) main at set_memory_region_test.c:426 3 0x0000ffffb8e67bdf: ?? ??:0 4 0x00000000004016db: _start at :? KVM_SET_USER_MEMORY_REGION IOCTL failed, rc: -1 errno: 22 slot: 2615 Fixes: 3bf0fcd75434 ("KVM: selftests: Speed up set_memory_region_test") Signed-off-by: Zenghui Yu Message-Id: <20210624070931.565-1-yuzenghui@huawei.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Fix kvm_check_cap() assertion

2021-06-17T17:06:57+00:00

KVM_CHECK_EXTENSION ioctl can return any negative value on error, and not necessarily -1. Change the assertion to reflect that. Signed-off-by: Fuad Tabba Message-Id: <20210615150443.1183365-1-tabba@google.com> Signed-off-by: Paolo Bonzini

KVM: selftests: Fix compiling errors when initializing the static structure

2021-06-10T11:46:10+00:00

Errors like below were produced from test_util.c when compiling the KVM selftests on my local platform. lib/test_util.c: In function 'vm_mem_backing_src_alias': lib/test_util.c:177:12: error: initializer element is not constant .flag = anon_flags, ^~~~~~~~~~ lib/test_util.c:177:12: note: (near initialization for 'aliases[0].flag') The reason is that we are using non-const expressions to initialize the static structure, which will probably trigger a compiling error/warning on stricter GCC versions. Fix it by converting the two const variables "anon_flags" and "anon_huge_flags" into more stable macros. Fixes: b3784bc28ccc0 ("KVM: selftests: refactor vm_mem_backing_src_type flags") Reported-by: Zenghui Yu Signed-off-by: Yanan Wang Message-Id: <20210610085418.35544-1-wangyanan55@huawei.com> Signed-off-by: Paolo Bonzini

selftests: kvm: Add support for customized slot0 memory size

2021-06-08T17:29:10+00:00

Until commit 39fe2fc96694 ("selftests: kvm: make allocation of extra memory take effect", 2021-05-27), parameter extra_mem_pages was used only to calculate the page table size for all the memory chunks, because real memory allocation happened with calls of vm_userspace_mem_region_add() after vm_create_default(). Commit 39fe2fc96694 however changed the meaning of extra_mem_pages to the size of memory slot 0. This makes the memory allocation more flexible, but makes it harder to account for the number of pages needed for the page tables. For example, memslot_perf_test has a small amount of memory in slot 0 but a lot in other slots, and adding that memory twice (both in slot 0 and with later calls to vm_userspace_mem_region_add()) causes an error that was fixed in commit 000ac4295339 ("selftests: kvm: fix overlapping addresses in memslot_perf_test", 2021-05-29) Since both uses are sensible, add a new parameter slot0_mem_pages to vm_create_with_vcpus() and some comments to clarify the meaning of slot0_mem_pages and extra_mem_pages. With this change, memslot_perf_test can go back to passing the number of memory pages as extra_mem_pages. Signed-off-by: Zhenzhong Duan Message-Id: <20210608233816.423958-4-zhenzhong.duan@intel.com> [Squashed in a single patch and rewrote the commit message. - Paolo] Signed-off-by: Paolo Bonzini

KVM: selftests: introduce P47V64 for s390x

2021-06-08T17:19:19+00:00

s390x can have up to 47bits of physical guest and 64bits of virtual address bits. Add a new address mode to avoid errors of testcases going beyond 47bits. Signed-off-by: Christian Borntraeger Message-Id: <20210608123954.10991-1-borntraeger@de.ibm.com> Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()") Cc: stable@vger.kernel.org Reviewed-by: David Matlack Signed-off-by: Paolo Bonzini

selftests: kvm: fix overlapping addresses in memslot_perf_test

2021-05-29T10:28:06+00:00

vm_create allocates memory and maps it close to GPA. This memory is separate from what is allocated in subsequent calls to vm_userspace_mem_region_add, so it is incorrect to pass the test memory size to vm_create_default. Just pass a small fixed amount of memory which can be used later for page table, otherwise GPAs are already allocated at MEM_GPA and the test aborts. Signed-off-by: Paolo Bonzini

selftests: kvm: do only 1 memslot_perf_test run by default

2021-05-27T11:45:57+00:00

The test takes a long time with the current implementation of memslots, so cut the run time a bit. Signed-off-by: Paolo Bonzini

KVM: selftests: add shared hugetlbfs backing source type

2021-05-27T11:45:57+00:00

This lets us run the demand paging test on top of a shared hugetlbfs-backed area. The "shared" is key, as this allows us to exercise userfaultfd minor faults on hugetlbfs. Signed-off-by: Axel Rasmussen Message-Id: <20210519200339.829146-11-axelrasmussen@google.com> Reviewed-by: Ben Gardon Signed-off-by: Paolo Bonzini

KVM: selftests: allow using UFFD minor faults for demand paging

2021-05-27T11:45:57+00:00

UFFD handling of MINOR faults is a new feature whose use case is to speed up demand paging (compared to MISSING faults). So, it's interesting to let this selftest exercise this new mode. Modify the demand paging test to have the option of using UFFD minor faults, as opposed to missing faults. Now, when turning on userfaultfd with '-u', the desired mode has to be specified ("MISSING" or "MINOR"). If we're in minor mode, before registering, prefault via the *alias*. This way, the guest will trigger minor faults, instead of missing faults, and we can UFFDIO_CONTINUE to resolve them. Modify the page fault handler function to use the right ioctl depending on the mode we're running in. In MINOR mode, use UFFDIO_CONTINUE. Signed-off-by: Axel Rasmussen Message-Id: <20210519200339.829146-10-axelrasmussen@google.com> Signed-off-by: Paolo Bonzini

KVM: selftests: create alias mappings when using shared memory

2021-05-27T11:45:56+00:00

When a memory region is added with a src_type specifying that it should use some kind of shared memory, also create an alias mapping to the same underlying physical pages. And, add an API so tests can get access to these alias addresses. Basically, for a guest physical address, let us look up the analogous host *alias* address. In a future commit, we'll modify the demand paging test to take advantage of this to exercise UFFD minor faults. The idea is, we pre-fault the underlying pages *via the alias*. When the *guest* faults, it gets a "minor" fault (PTEs don't exist yet, but a page is already in the page cache). Then, the userfaultfd theads can handle the fault: they could potentially modify the underlying memory *via the alias* if they wanted to, and then they install the PTEs and let the guest carry on via a UFFDIO_CONTINUE ioctl. Reviewed-by: Ben Gardon Signed-off-by: Axel Rasmussen Message-Id: <20210519200339.829146-9-axelrasmussen@google.com> Signed-off-by: Paolo Bonzini