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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: rientjes@google.com, seanjc@google.com, ackerleytng@google.com, vannapurve@google.com, michael.roth@amd.com, jiaqiyan@google.com, tabba@google.com, dave.hansen@linux.intel.com, Lisa Wang Content-Type: text/plain; charset="utf-8" Test that + memory failure handling results in unmapping of bad memory from stage 2 page tables, hence requiring faulting on next guest access + when the guest tries to fault a poisoned page from guest_memfd, the userspace VMM informed with EHWPOISON Co-developed-by: Ackerley Tng Signed-off-by: Ackerley Tng Signed-off-by: Lisa Wang --- tools/testing/selftests/kvm/guest_memfd_test.c | 70 +++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index 0ea4e7d7e6d5..6615ee8bfcd8 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -26,6 +26,7 @@ #include "ucall_common.h" static size_t page_size; +static uint64_t test_memory_failure_guest_gpa; static void test_file_read_write(int fd, size_t total_size) { @@ -637,6 +638,73 @@ static void test_guest_memfd_guest(void) kvm_vm_free(vm); } +static void __guest_code_read(void) +{ + uint8_t *mem = (uint8_t *)test_memory_failure_guest_gpa; + + READ_ONCE(*mem); + GUEST_SYNC(0); + READ_ONCE(*mem); + GUEST_DONE(); +} + +static void guest_read(struct kvm_vcpu *vcpu, int expected_errno) +{ + if (expected_errno) { + TEST_ASSERT_EQ(_vcpu_run(vcpu), -1); + TEST_ASSERT_EQ(errno, expected_errno); + } else { + vcpu_run(vcpu); + TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_SYNC); + } +} + +static void test_memory_failure_guest(void) +{ + const uint64_t gpa = SZ_4G; + const int slot = 1; + + unsigned long memory_failure_pfn; + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + uint8_t *mem; + size_t size; + int fd; + + if (!kvm_has_cap(KVM_CAP_GUEST_MEMFD_FLAGS)) + return; + + vm = __vm_create_shape_with_one_vcpu(VM_SHAPE_DEFAULT, &vcpu, 1, __guest_code_read); + + size = vm->page_size; + fd = vm_create_guest_memfd(vm, size, GUEST_MEMFD_FLAG_MMAP | GUEST_MEMFD_FLAG_INIT_SHARED); + vm_set_user_memory_region2(vm, slot, KVM_MEM_GUEST_MEMFD, gpa, size, NULL, fd, 0); + + mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT(mem != MAP_FAILED, "mmap() for guest_memfd should succeed."); + virt_pg_map(vm, gpa, gpa); + + test_memory_failure_guest_gpa = gpa; + sync_global_to_guest(vm, test_memory_failure_guest_gpa); + + /* Fault in page to read pfn, then unmap page for testing. */ + READ_ONCE(*mem); + memory_failure_pfn = addr_to_pfn(mem); + munmap(mem, size); + + /* Fault page into stage2 page tables. */ + guest_read(vcpu, 0); + + mark_memory_failure(memory_failure_pfn, 0); + + guest_read(vcpu, EHWPOISON); + + close(fd); + kvm_vm_free(vm); + + unmark_memory_failure(memory_failure_pfn, 0); +} + int main(int argc, char *argv[]) { unsigned long vm_types, vm_type; @@ -644,7 +712,6 @@ int main(int argc, char *argv[]) TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD)); page_size = getpagesize(); - /* * Not all architectures support KVM_CAP_VM_TYPES. However, those that * support guest_memfd have that support for the default VM type. @@ -657,4 +724,5 @@ int main(int argc, char *argv[]) test_guest_memfd(vm_type); test_guest_memfd_guest(); + test_memory_failure_guest(); } -- 2.53.0.1213.gd9a14994de-goog