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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-06-07 23:44:53 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-06-07 23:44:53 +0200 |
commit | 8d6b029e15ab47986e486f52b2b768ca6faa5cbe (patch) | |
tree | 9b55a7f9cb3a6eb0ebe07959411acd8607a4ed77 /tools | |
parent | Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm6... (diff) | |
parent | KVM: s390x: selftests: Add shared zeropage test (diff) | |
download | linux-8d6b029e15ab47986e486f52b2b768ca6faa5cbe.tar.xz linux-8d6b029e15ab47986e486f52b2b768ca6faa5cbe.zip |
Merge tag 's390-6.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Alexander Gordeev:
- Do not create PT_LOAD program header for the kenel image when the
virtual memory informaton in OS_INFO data is not available. That
fixes stand-alone dump failures against kernels that do not provide
the virtual memory informaton
- Add KVM s390 shared zeropage selftest
* tag 's390-6.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
KVM: s390x: selftests: Add shared zeropage test
s390/crash: Do not use VM info if os_info does not have it
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/kvm/Makefile | 1 | ||||
-rw-r--r-- | tools/testing/selftests/kvm/s390x/shared_zeropage_test.c | 111 |
2 files changed, 112 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index ce8ff8e8ce3a..ac280dcba996 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -183,6 +183,7 @@ TEST_GEN_PROGS_s390x += s390x/sync_regs_test TEST_GEN_PROGS_s390x += s390x/tprot TEST_GEN_PROGS_s390x += s390x/cmma_test TEST_GEN_PROGS_s390x += s390x/debug_test +TEST_GEN_PROGS_s390x += s390x/shared_zeropage_test TEST_GEN_PROGS_s390x += demand_paging_test TEST_GEN_PROGS_s390x += dirty_log_test TEST_GEN_PROGS_s390x += guest_print_test diff --git a/tools/testing/selftests/kvm/s390x/shared_zeropage_test.c b/tools/testing/selftests/kvm/s390x/shared_zeropage_test.c new file mode 100644 index 000000000000..bba0d9a6dcc8 --- /dev/null +++ b/tools/testing/selftests/kvm/s390x/shared_zeropage_test.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Test shared zeropage handling (with/without storage keys) + * + * Copyright (C) 2024, Red Hat, Inc. + */ +#include <sys/mman.h> + +#include <linux/fs.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "kselftest.h" +#include "ucall_common.h" + +static void set_storage_key(void *addr, uint8_t skey) +{ + asm volatile("sske %0,%1" : : "d" (skey), "a" (addr)); +} + +static void guest_code(void) +{ + /* Issue some storage key instruction. */ + set_storage_key((void *)0, 0x98); + GUEST_DONE(); +} + +/* + * Returns 1 if the shared zeropage is mapped, 0 if something else is mapped. + * Returns < 0 on error or if nothing is mapped. + */ +static int maps_shared_zeropage(int pagemap_fd, void *addr) +{ + struct page_region region; + struct pm_scan_arg arg = { + .start = (uintptr_t)addr, + .end = (uintptr_t)addr + 4096, + .vec = (uintptr_t)®ion, + .vec_len = 1, + .size = sizeof(struct pm_scan_arg), + .category_mask = PAGE_IS_PFNZERO, + .category_anyof_mask = PAGE_IS_PRESENT, + .return_mask = PAGE_IS_PFNZERO, + }; + return ioctl(pagemap_fd, PAGEMAP_SCAN, &arg); +} + +int main(int argc, char *argv[]) +{ + char *mem, *page0, *page1, *page2, tmp; + const size_t pagesize = getpagesize(); + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + int pagemap_fd; + + ksft_print_header(); + ksft_set_plan(3); + + /* + * We'll use memory that is not mapped into the VM for simplicity. + * Shared zeropages are enabled/disabled per-process. + */ + mem = mmap(0, 3 * pagesize, PROT_READ, MAP_PRIVATE | MAP_ANON, -1, 0); + TEST_ASSERT(mem != MAP_FAILED, "mmap() failed"); + + /* Disable THP. Ignore errors on older kernels. */ + madvise(mem, 3 * pagesize, MADV_NOHUGEPAGE); + + page0 = mem; + page1 = page0 + pagesize; + page2 = page1 + pagesize; + + /* Can we even detect shared zeropages? */ + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + TEST_REQUIRE(pagemap_fd >= 0); + + tmp = *page0; + asm volatile("" : "+r" (tmp)); + TEST_REQUIRE(maps_shared_zeropage(pagemap_fd, page0) == 1); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + /* Verify that we get the shared zeropage after VM creation. */ + tmp = *page1; + asm volatile("" : "+r" (tmp)); + ksft_test_result(maps_shared_zeropage(pagemap_fd, page1) == 1, + "Shared zeropages should be enabled\n"); + + /* + * Let our VM execute a storage key instruction that should + * unshare all shared zeropages. + */ + vcpu_run(vcpu); + get_ucall(vcpu, &uc); + TEST_ASSERT_EQ(uc.cmd, UCALL_DONE); + + /* Verify that we don't have a shared zeropage anymore. */ + ksft_test_result(!maps_shared_zeropage(pagemap_fd, page1), + "Shared zeropage should be gone\n"); + + /* Verify that we don't get any new shared zeropages. */ + tmp = *page2; + asm volatile("" : "+r" (tmp)); + ksft_test_result(!maps_shared_zeropage(pagemap_fd, page2), + "Shared zeropages should be disabled\n"); + + kvm_vm_free(vm); + + ksft_finished(); +} |