diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 21 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/ucall_common.h | 8 |
2 files changed, 19 insertions, 10 deletions
diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c index d86c4e4d1c82..c62ec4d7f6a3 100644 --- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c +++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c @@ -239,10 +239,6 @@ static void guest_svc_handler(struct ex_regs *regs) svc_addr = regs->pc; } -enum single_step_op { - SINGLE_STEP_ENABLE = 0, -}; - static void guest_code_ss(int test_cnt) { uint64_t i; @@ -253,8 +249,16 @@ static void guest_code_ss(int test_cnt) w_bvr = i << 2; w_wvr = i << 2; - /* Enable Single Step execution */ - GUEST_SYNC(SINGLE_STEP_ENABLE); + /* + * Enable Single Step execution. Note! This _must_ be a bare + * ucall as the ucall() path uses atomic operations to manage + * the ucall structures, and the built-in "atomics" are usually + * implemented via exclusive access instructions. The exlusive + * monitor is cleared on ERET, and so taking debug exceptions + * during a LDREX=>STREX sequence will prevent forward progress + * and hang the guest/test. + */ + GUEST_UCALL_NONE(); /* * The userspace will verify that the pc is as expected during @@ -356,12 +360,9 @@ void test_single_step_from_userspace(int test_cnt) break; } - TEST_ASSERT(cmd == UCALL_SYNC, + TEST_ASSERT(cmd == UCALL_NONE, "Unexpected ucall cmd 0x%lx", cmd); - TEST_ASSERT(uc.args[1] == SINGLE_STEP_ENABLE, - "Unexpected ucall action 0x%lx", uc.args[1]); - debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP; ss_enable = true; diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h index bdd373189a77..1a6aaef5ccae 100644 --- a/tools/testing/selftests/kvm/include/ucall_common.h +++ b/tools/testing/selftests/kvm/include/ucall_common.h @@ -35,6 +35,14 @@ void ucall(uint64_t cmd, int nargs, ...); uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc); void ucall_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa); +/* + * Perform userspace call without any associated data. This bare call avoids + * allocating a ucall struct, which can be useful if the atomic operations in + * the full ucall() are problematic and/or unwanted. Note, this will come out + * as UCALL_NONE on the backend. + */ +#define GUEST_UCALL_NONE() ucall_arch_do_ucall((vm_vaddr_t)NULL) + #define GUEST_SYNC_ARGS(stage, arg1, arg2, arg3, arg4) \ ucall(UCALL_SYNC, 6, "hello", stage, arg1, arg2, arg3, arg4) #define GUEST_SYNC(stage) ucall(UCALL_SYNC, 2, "hello", stage) |