Re: [RFC PATCH v2 8/9] KVM: selftests: arm64: Extend kvm_page_table_test to run guest code in vEL2

On Mon, May 12, 2025 at 03:52:50AM -0700, Ganapatrao Kulkarni wrote:

Adding code to run guest_code in vEL2. NV is enabled using command line argument and it is disabled by default.

NV is only enabled on ARM64, for other architectures the test will exit with an ASSERT, if tried to run with NV enabled.

I'm seeing this in QEMU TCG mode, does this mean the limitation of the emulation?

$ sudo /mnt/projects/linux/tools/testing/selftests/kvm/arm64/page_fault_test -m 3 -s anonymous Random seed: 0x6b8b4567 ==== Test Assertion Failure ==== arm64/page_fault_test.c:632: test->expected_events.uffd_faults == events.uffd_faults pid=769 tid=769 errno=9 - Bad file descriptor 1 0x000000000040325b: check_event_counts at page_fault_test.c:632 2 (inlined by) run_test at page_fault_test.c:739 3 0x0000000000403cbf: for_each_guest_mode at guest_modes.c:96 4 0x0000000000401cfb: for_each_test_and_guest_mode at page_fault_test.c:1107 5 (inlined by) main at page_fault_test.c:1133 6 0x0000ffff848122db: ?? ??:0 7 0x0000ffff848123bb: ?? ??:0 8 0x0000000000401def: _start at ??:? 0x2 != 0x1 (test->expected_events.uffd_faults != events.uffd_faults)

Thanks, Itaru.

Signed-off-by: Ganapatrao Kulkarni gankulkarni@os.amperecomputing.com

.../selftests/kvm/kvm_page_table_test.c | 30 +++++++++++++++++-- 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c index dd8b12f626d3..383f9d134ecb 100644 --- a/tools/testing/selftests/kvm/kvm_page_table_test.c +++ b/tools/testing/selftests/kvm/kvm_page_table_test.c @@ -20,6 +20,10 @@ #include "guest_modes.h" #include "ucall_common.h" +#ifdef __aarch64__ +#include <nv_util.h> +#endif

#define TEST_MEM_SLOT_INDEX 1 /* Default size(1GB) of the memory for testing */ @@ -229,7 +233,9 @@ static void *vcpu_worker(void *data) struct test_params { uint64_t phys_offset; uint64_t test_mem_size;

• bool is_nested; enum vm_mem_backing_src_type src_type;
• int fd;

}; static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg) @@ -252,8 +258,17 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg) /* Create a VM with enough guest pages */ guest_num_pages = test_mem_size / guest_page_size;

• vm = __vm_create_with_vcpus(VM_SHAPE(mode), nr_vcpus, guest_num_pages,

• if (p->is_nested) {

+#ifdef __aarch64__

• vm = __nv_vm_create_with_vcpus_gic(VM_SHAPE(mode), nr_vcpus,
  

• 		test_args.vcpus, guest_num_pages, &p->fd, guest_code);
  

+#else

• TEST_FAIL("Nested Not Supported");
  

+#endif

• } else {

• vm = __vm_create_with_vcpus(VM_SHAPE(mode), nr_vcpus, guest_num_pages,
  	    guest_code, test_args.vcpus);
  

• }

/* Align down GPA of the testing memslot */ if (!p->phys_offset) @@ -345,6 +360,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) struct timespec start; struct timespec ts_diff; int ret, i;

• struct test_params *p = (struct test_params *)arg;

/* Create VM with vCPUs and make some pre-initialization */ vm = pre_init_before_test(mode, arg); @@ -414,6 +430,8 @@ static void run_test(enum vm_guest_mode mode, void *arg) TEST_ASSERT(ret == 0, "Error in sem_destroy"); free(vcpu_threads);

• if (p->is_nested)

• close(p->fd);
  

  kvm_vm_free(vm);

} @@ -421,7 +439,7 @@ static void help(char *name) { puts(""); printf("usage: %s [-h] [-p offset] [-m mode] "

•       "[-b mem-size] [-v vcpus] [-s mem-type]\n", name);
  

•       "[-b mem-size] [-v vcpus] [-s mem-type] [-g nv]\n", name);
  

  puts(""); printf(" -p: specify guest physical test memory offset\n" " Warning: a low offset can conflict with the loaded test code.\n");

@@ -430,6 +448,8 @@ static void help(char *name) " (default: 1G)\n"); printf(" -v: specify the number of vCPUs to run\n" " (default: 1)\n");

• printf(" -g: Enable Nested Virtualization, run guest code as guest hypervisor.\n"

•       "     (default: Disabled)\n");
  

  backing_src_help("-s"); puts("");

} @@ -440,12 +460,13 @@ int main(int argc, char *argv[]) struct test_params p = { .test_mem_size = DEFAULT_TEST_MEM_SIZE, .src_type = DEFAULT_VM_MEM_SRC,

• .is_nested = false,
  

  }; int opt;

guest_modes_append_default();

• while ((opt = getopt(argc, argv, "hp:m:b:v:s:")) != -1) {

• while ((opt = getopt(argc, argv, "hp:m:b:v:s:g:")) != -1) { switch (opt) { case 'p': p.phys_offset = strtoull(optarg, NULL, 0);

@@ -464,6 +485,9 @@ int main(int argc, char *argv[]) case 's': p.src_type = parse_backing_src_type(optarg); break;

• case 'g':
  

• 	p.is_nested = atoi_non_negative("Is Nested", optarg);
  

• 	break;
  

  case 'h': default: help(argv[0]);

-- 2.48.1