svc_addr = regs->pc;
}
-enum single_step_op {
- SINGLE_STEP_ENABLE = 0,
-};
-
static void guest_code_ss(int test_cnt)
{
uint64_t i;
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
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;
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)