From: Ackerley Tng <ackerleytng@xxxxxxxxxx> "Testing private access when memslot gets deleted" tests the behavior of KVM when a private memslot gets deleted while the VM is using the private memslot. When KVM looks up the deleted (slot = NULL) memslot, KVM should exit to userspace with KVM_EXIT_MEMORY_FAULT. In the second test, upon a private access to non-private memslot, KVM should also exit to userspace with KVM_EXIT_MEMORY_FAULT. sean: These testcases belong in set_memory_region_test.c, they're private variants on existing testscases and aren't as robust, e.g. don't ensure the vCPU is actually running and accessing memory when converting and deleting. Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- tools/testing/selftests/kvm/Makefile | 1 + .../kvm/x86_64/private_mem_kvm_exits_test.c | 121 ++++++++++++++++++ 2 files changed, 122 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 2b1ef809d73a..f7fdd8244547 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -82,6 +82,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/nested_exceptions_test TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test TEST_GEN_PROGS_x86_64 += x86_64/pmu_event_filter_test TEST_GEN_PROGS_x86_64 += x86_64/private_mem_conversions_test +TEST_GEN_PROGS_x86_64 += x86_64/private_mem_kvm_exits_test TEST_GEN_PROGS_x86_64 += x86_64/set_boot_cpu_id TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test TEST_GEN_PROGS_x86_64 += x86_64/smaller_maxphyaddr_emulation_test diff --git a/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c b/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c new file mode 100644 index 000000000000..1a61c51c2390 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022, Google LLC. + */ +#include <linux/kvm.h> +#include <pthread.h> +#include <stdint.h> + +#include "kvm_util.h" +#include "processor.h" +#include "test_util.h" + +/* Arbitrarily selected to avoid overlaps with anything else */ +#define EXITS_TEST_GVA 0xc0000000 +#define EXITS_TEST_GPA EXITS_TEST_GVA +#define EXITS_TEST_NPAGES 1 +#define EXITS_TEST_SIZE (EXITS_TEST_NPAGES * PAGE_SIZE) +#define EXITS_TEST_SLOT 10 + +static uint64_t guest_repeatedly_read(void) +{ + volatile uint64_t value; + + while (true) + value = *((uint64_t *) EXITS_TEST_GVA); + + return value; +} + +static uint32_t run_vcpu_get_exit_reason(struct kvm_vcpu *vcpu) +{ + int r; + + r = _vcpu_run(vcpu); + if (r) { + TEST_ASSERT(errno == EFAULT, KVM_IOCTL_ERROR(KVM_RUN, r)); + TEST_ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_MEMORY_FAULT); + } + return vcpu->run->exit_reason; +} + +const struct vm_shape protected_vm_shape = { + .mode = VM_MODE_DEFAULT, + .type = KVM_X86_SW_PROTECTED_VM, +}; + +static void test_private_access_memslot_deleted(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + pthread_t vm_thread; + void *thread_return; + uint32_t exit_reason; + + vm = vm_create_shape_with_one_vcpu(protected_vm_shape, &vcpu, + guest_repeatedly_read); + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + EXITS_TEST_GPA, EXITS_TEST_SLOT, + EXITS_TEST_NPAGES, + KVM_MEM_PRIVATE); + + virt_map(vm, EXITS_TEST_GVA, EXITS_TEST_GPA, EXITS_TEST_NPAGES); + + /* Request to access page privately */ + vm_mem_set_private(vm, EXITS_TEST_GPA, EXITS_TEST_SIZE); + + pthread_create(&vm_thread, NULL, + (void *(*)(void *))run_vcpu_get_exit_reason, + (void *)vcpu); + + vm_mem_region_delete(vm, EXITS_TEST_SLOT); + + pthread_join(vm_thread, &thread_return); + exit_reason = (uint32_t)(uint64_t)thread_return; + + TEST_ASSERT_EQ(exit_reason, KVM_EXIT_MEMORY_FAULT); + TEST_ASSERT_EQ(vcpu->run->memory_fault.flags, KVM_MEMORY_EXIT_FLAG_PRIVATE); + TEST_ASSERT_EQ(vcpu->run->memory_fault.gpa, EXITS_TEST_GPA); + TEST_ASSERT_EQ(vcpu->run->memory_fault.size, EXITS_TEST_SIZE); + + kvm_vm_free(vm); +} + +static void test_private_access_memslot_not_private(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + uint32_t exit_reason; + + vm = vm_create_shape_with_one_vcpu(protected_vm_shape, &vcpu, + guest_repeatedly_read); + + /* Add a non-private memslot (flags = 0) */ + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + EXITS_TEST_GPA, EXITS_TEST_SLOT, + EXITS_TEST_NPAGES, 0); + + virt_map(vm, EXITS_TEST_GVA, EXITS_TEST_GPA, EXITS_TEST_NPAGES); + + /* Request to access page privately */ + vm_mem_set_private(vm, EXITS_TEST_GPA, EXITS_TEST_SIZE); + + exit_reason = run_vcpu_get_exit_reason(vcpu); + + TEST_ASSERT_EQ(exit_reason, KVM_EXIT_MEMORY_FAULT); + TEST_ASSERT_EQ(vcpu->run->memory_fault.flags, KVM_MEMORY_EXIT_FLAG_PRIVATE); + TEST_ASSERT_EQ(vcpu->run->memory_fault.gpa, EXITS_TEST_GPA); + TEST_ASSERT_EQ(vcpu->run->memory_fault.size, EXITS_TEST_SIZE); + + kvm_vm_free(vm); +} + +int main(int argc, char *argv[]) +{ + TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD)); + TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM)); + + test_private_access_memslot_deleted(); + test_private_access_memslot_not_private(); +} -- 2.42.0.283.g2d96d420d3-goog