From: Ryan Afranji afranji@google.com
Adds a test that sets up shared memory between the host and guest.
Signed-off-by: Ryan Afranji afranji@google.com Signed-off-by: Sagi Shahar sagis@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/x86_64/tdx/tdx.h | 2 + .../kvm/include/x86_64/tdx/tdx_util.h | 2 + .../selftests/kvm/lib/x86_64/tdx/tdx.c | 26 ++++ .../selftests/kvm/lib/x86_64/tdx/tdx_util.c | 25 ++++ .../kvm/x86_64/tdx_shared_mem_test.c | 135 ++++++++++++++++++ 6 files changed, 191 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/tdx_shared_mem_test.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 80d4a50eeb9f..8c0a6b395ee5 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -156,6 +156,7 @@ TEST_GEN_PROGS_x86_64 += steal_time TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test TEST_GEN_PROGS_x86_64 += system_counter_offset_test TEST_GEN_PROGS_x86_64 += x86_64/tdx_vm_tests +TEST_GEN_PROGS_x86_64 += x86_64/tdx_shared_mem_test
# Compiled outputs used by test targets TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h index 6b176de1e795..db4cc62abb5d 100644 --- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h @@ -8,6 +8,7 @@ #define TDG_VP_INFO 1
#define TDG_VP_VMCALL_GET_TD_VM_CALL_INFO 0x10000 +#define TDG_VP_VMCALL_MAP_GPA 0x10001 #define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003
#define TDG_VP_VMCALL_INSTRUCTION_CPUID 10 @@ -36,5 +37,6 @@ uint64_t tdg_vp_vmcall_instruction_cpuid(uint32_t eax, uint32_t ecx, uint64_t tdg_vp_info(uint64_t *rcx, uint64_t *rdx, uint64_t *r8, uint64_t *r9, uint64_t *r10, uint64_t *r11); +uint64_t tdg_vp_vmcall_map_gpa(uint64_t address, uint64_t size, uint64_t *data_out);
#endif // SELFTEST_TDX_TDX_H diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h index 32dd6b8fda46..3e850ecb85a6 100644 --- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h @@ -13,5 +13,7 @@ void td_initialize(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, uint64_t attributes); void td_finalize(struct kvm_vm *vm); void td_vcpu_run(struct kvm_vcpu *vcpu); +void handle_memory_conversion(struct kvm_vm *vm, uint64_t gpa, uint64_t size, + bool shared_to_private);
#endif // SELFTESTS_TDX_KVM_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c index bcd9cceb3372..061a5c0bef34 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c @@ -4,9 +4,11 @@
#include "tdx/tdcall.h" #include "tdx/tdx.h" +#include "tdx/tdx_util.h"
void handle_userspace_tdg_vp_vmcall_exit(struct kvm_vcpu *vcpu) { + struct kvm_vm *vm = vcpu->vm; struct kvm_tdx_vmcall *vmcall_info = &vcpu->run->tdx.u.vmcall; uint64_t vmcall_subfunction = vmcall_info->subfunction;
@@ -20,6 +22,14 @@ void handle_userspace_tdg_vp_vmcall_exit(struct kvm_vcpu *vcpu) vcpu->run->system_event.data[2] = vmcall_info->in_r13; vmcall_info->status_code = 0; break; + case TDG_VP_VMCALL_MAP_GPA: + uint64_t gpa = vmcall_info->in_r12 & ~vm->arch.s_bit; + bool shared_to_private = !(vm->arch.s_bit & + vmcall_info->in_r12); + handle_memory_conversion(vm, gpa, vmcall_info->in_r13, + shared_to_private); + vmcall_info->status_code = 0; + break; default: TEST_FAIL("TD VMCALL subfunction %lu is unsupported.\n", vmcall_subfunction); @@ -210,3 +220,19 @@ uint64_t tdg_vp_info(uint64_t *rcx, uint64_t *rdx,
return ret; } + +uint64_t tdg_vp_vmcall_map_gpa(uint64_t address, uint64_t size, uint64_t *data_out) +{ + uint64_t ret; + struct tdx_hypercall_args args = { + .r11 = TDG_VP_VMCALL_MAP_GPA, + .r12 = address, + .r13 = size + }; + + ret = __tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT); + + if (data_out) + *data_out = args.r11; + return ret; +} diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c index d745bb6287c1..92fa6bd13229 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c @@ -531,3 +531,28 @@ void td_vcpu_run(struct kvm_vcpu *vcpu) handle_userspace_tdg_vp_vmcall_exit(vcpu); } } + +/** + * Handle conversion of memory with @size beginning @gpa for @vm. Set + * @shared_to_private to true for shared to private conversions and false + * otherwise. + * + * Since this is just for selftests, we will just keep both pieces of backing + * memory allocated and not deallocate/allocate memory; we'll just do the + * minimum of calling KVM_MEMORY_ENCRYPT_REG_REGION and + * KVM_MEMORY_ENCRYPT_UNREG_REGION. + */ +void handle_memory_conversion(struct kvm_vm *vm, uint64_t gpa, uint64_t size, + bool shared_to_private) +{ + struct kvm_memory_attributes range; + + range.address = gpa; + range.size = size; + range.attributes = shared_to_private ? KVM_MEMORY_ATTRIBUTE_PRIVATE : 0; + range.flags = 0; + + printf("\t ... calling KVM_SET_MEMORY_ATTRIBUTES ioctl with gpa=%#lx, size=%#lx, attributes=%#llx\n", gpa, size, range.attributes); + + vm_ioctl(vm, KVM_SET_MEMORY_ATTRIBUTES, &range); +} diff --git a/tools/testing/selftests/kvm/x86_64/tdx_shared_mem_test.c b/tools/testing/selftests/kvm/x86_64/tdx_shared_mem_test.c new file mode 100644 index 000000000000..ba6bdc470270 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/tdx_shared_mem_test.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/kvm.h> +#include <stdint.h> + +#include "kvm_util_base.h" +#include "processor.h" +#include "tdx/tdcall.h" +#include "tdx/tdx.h" +#include "tdx/tdx_util.h" +#include "tdx/test_util.h" +#include "test_util.h" + +#define TDX_SHARED_MEM_TEST_PRIVATE_GVA (0x80000000) +#define TDX_SHARED_MEM_TEST_VADDR_SHARED_MASK BIT_ULL(30) +#define TDX_SHARED_MEM_TEST_SHARED_GVA \ + (TDX_SHARED_MEM_TEST_PRIVATE_GVA | \ + TDX_SHARED_MEM_TEST_VADDR_SHARED_MASK) + +#define TDX_SHARED_MEM_TEST_GUEST_WRITE_VALUE (0xcafecafe) +#define TDX_SHARED_MEM_TEST_HOST_WRITE_VALUE (0xabcdabcd) + +#define TDX_SHARED_MEM_TEST_INFO_PORT 0x87 + +/* + * Shared variables between guest and host + */ +static uint64_t test_mem_private_gpa; +static uint64_t test_mem_shared_gpa; + +void guest_shared_mem(void) +{ + uint32_t *test_mem_shared_gva = + (uint32_t *)TDX_SHARED_MEM_TEST_SHARED_GVA; + + uint64_t placeholder; + uint64_t ret; + + /* Map gpa as shared */ + ret = tdg_vp_vmcall_map_gpa(test_mem_shared_gpa, PAGE_SIZE, + &placeholder); + if (ret) + tdx_test_fatal_with_data(ret, __LINE__); + + *test_mem_shared_gva = TDX_SHARED_MEM_TEST_GUEST_WRITE_VALUE; + + /* Exit so host can read shared value */ + ret = tdg_vp_vmcall_instruction_io(TDX_SHARED_MEM_TEST_INFO_PORT, 4, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE, + &placeholder); + if (ret) + tdx_test_fatal_with_data(ret, __LINE__); + + /* Read value written by host and send it back out for verification */ + ret = tdg_vp_vmcall_instruction_io(TDX_SHARED_MEM_TEST_INFO_PORT, 4, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE, + (uint64_t *)test_mem_shared_gva); + if (ret) + tdx_test_fatal_with_data(ret, __LINE__); +} + +int verify_shared_mem(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + vm_vaddr_t test_mem_private_gva; + uint32_t *test_mem_hva; + + vm = td_create(); + td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0); + vcpu = td_vcpu_add(vm, 0, guest_shared_mem); + + /* + * Set up shared memory page for testing by first allocating as private + * and then mapping the same GPA again as shared. This way, the TD does + * not have to remap its page tables at runtime. + */ + test_mem_private_gva = vm_vaddr_alloc(vm, vm->page_size, + TDX_SHARED_MEM_TEST_PRIVATE_GVA); + TEST_ASSERT_EQ(test_mem_private_gva, TDX_SHARED_MEM_TEST_PRIVATE_GVA); + + test_mem_hva = addr_gva2hva(vm, test_mem_private_gva); + TEST_ASSERT(test_mem_hva != NULL, + "Guest address not found in guest memory regions\n"); + + test_mem_private_gpa = addr_gva2gpa(vm, test_mem_private_gva); + virt_pg_map_shared(vm, TDX_SHARED_MEM_TEST_SHARED_GVA, + test_mem_private_gpa); + + test_mem_shared_gpa = test_mem_private_gpa | BIT_ULL(vm->pa_bits - 1); + sync_global_to_guest(vm, test_mem_private_gpa); + sync_global_to_guest(vm, test_mem_shared_gpa); + + td_finalize(vm); + + printf("Verifying shared memory accesses for TDX\n"); + + /* Begin guest execution; guest writes to shared memory. */ + printf("\t ... Starting guest execution\n"); + + /* Handle map gpa as shared */ + td_vcpu_run(vcpu); + TDX_TEST_CHECK_GUEST_FAILURE(vcpu); + + td_vcpu_run(vcpu); + TDX_TEST_ASSERT_IO(vcpu, TDX_SHARED_MEM_TEST_INFO_PORT, 4, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE); + TEST_ASSERT_EQ(*test_mem_hva, TDX_SHARED_MEM_TEST_GUEST_WRITE_VALUE); + + *test_mem_hva = TDX_SHARED_MEM_TEST_HOST_WRITE_VALUE; + td_vcpu_run(vcpu); + TDX_TEST_ASSERT_IO(vcpu, TDX_SHARED_MEM_TEST_INFO_PORT, 4, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE); + TEST_ASSERT_EQ( + *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset), + TDX_SHARED_MEM_TEST_HOST_WRITE_VALUE); + + printf("\t ... PASSED\n"); + + kvm_vm_free(vm); + + return 0; +} + +int main(int argc, char **argv) +{ + if (!is_tdx_enabled()) { + printf("TDX is not supported by the KVM\n" + "Skipping the TDX tests.\n"); + return 0; + } + + return verify_shared_mem(); +}