Include 2 basic tests for receiving a User IPI:
1. Receiver is spinning in userspace.
2. Receiver is blocked in the kernel.
The selftests need gcc with 'muintr' support to compile.
GCC 11 (recently released) has support for this.
Signed-off-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
---
tools/testing/selftests/x86/Makefile | 10 ++
tools/testing/selftests/x86/uintr.c | 147 +++++++++++++++++++++++++++
2 files changed, 157 insertions(+)
create mode 100644 tools/testing/selftests/x86/uintr.c
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index b4142cd1c5c2..38588221b09e 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -9,6 +9,7 @@ UNAME_M := $(shell uname -m)
CAN_BUILD_I386 := $(shell ./check_cc.sh $(CC) trivial_32bit_program.c -m32)
CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c)
CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie)
+CAN_BUILD_UINTR := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c -muintr)
TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \
check_initial_reg_state sigreturn iopl ioperm \
@@ -19,6 +20,11 @@ TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \
vdso_restorer
TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering \
corrupt_xstate_header
+
+ifeq ($(CAN_BUILD_UINTR),1)
+TARGETS_C_64BIT_ONLY := $(TARGETS_C_64BIT_ONLY) uintr
+endif
+
# Some selftests require 32bit support enabled also on 64bit systems
TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall
@@ -41,6 +47,10 @@ ifeq ($(CAN_BUILD_WITH_NOPIE),1)
CFLAGS += -no-pie
endif
+ifeq ($(CAN_BUILD_UINTR),1)
+CFLAGS += -muintr
+endif
+
define gen-target-rule-32
$(1) $(1)_32: $(OUTPUT)/$(1)_32
.PHONY: $(1) $(1)_32
diff --git a/tools/testing/selftests/x86/uintr.c b/tools/testing/selftests/x86/uintr.c
new file mode 100644
index 000000000000..61a53526f2fa
--- /dev/null
+++ b/tools/testing/selftests/x86/uintr.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020, Intel Corporation.
+ *
+ * Sohil Mehta <sohil.mehta@xxxxxxxxx>
+ */
+#define _GNU_SOURCE
+#include <syscall.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <x86gprintrin.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+#ifndef __x86_64__
+# error This test is 64-bit only
+#endif
+
+#ifndef __NR_uintr_register_handler
+#define __NR_uintr_register_handler 449
+#define __NR_uintr_unregister_handler 450
+#define __NR_uintr_create_fd 451
+#define __NR_uintr_register_sender 452
+#define __NR_uintr_unregister_sender 453
+#define __NR_uintr_wait 454
+#endif
+
+#define uintr_register_handler(handler, flags) syscall(__NR_uintr_register_handler, handler, flags)
+#define uintr_unregister_handler(flags) syscall(__NR_uintr_unregister_handler, flags)
+#define uintr_create_fd(vector, flags) syscall(__NR_uintr_create_fd, vector, flags)
+#define uintr_register_sender(fd, flags) syscall(__NR_uintr_register_sender, fd, flags)
+#define uintr_unregister_sender(fd, flags) syscall(__NR_uintr_unregister_sender, fd, flags)
+#define uintr_wait(flags) syscall(__NR_uintr_wait, flags)
+
+unsigned long uintr_received;
+unsigned int uintr_fd;
+
+void __attribute__((interrupt))__attribute__((target("general-regs-only", "inline-all-stringops")))
+uintr_handler(struct __uintr_frame *ui_frame,
+ unsigned long long vector)
+{
+ uintr_received = 1;
+}
+
+void receiver_setup_interrupt(void)
+{
+ int vector = 0;
+ int ret;
+
+ /* Register interrupt handler */
+ if (uintr_register_handler(uintr_handler, 0)) {
+ printf("[FAIL]\tInterrupt handler register error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Create uintr_fd */
+ ret = uintr_create_fd(vector, 0);
+ if (ret < 0) {
+ printf("[FAIL]\tInterrupt vector registration error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ uintr_fd = ret;
+}
+
+void *sender_thread(void *arg)
+{
+ long sleep_usec = (long)arg;
+ int uipi_index;
+
+ uipi_index = uintr_register_sender(uintr_fd, 0);
+ if (uipi_index < 0) {
+ printf("[FAIL]\tSender register error\n");
+ return NULL;
+ }
+
+ /* Sleep before sending IPI to allow the receiver to block in the kernel */
+ if (sleep_usec)
+ usleep(sleep_usec);
+
+ printf("\tother thread: sending IPI\n");
+ _senduipi(uipi_index);
+
+ uintr_unregister_sender(uintr_fd, 0);
+
+ return NULL;
+}
+
+static inline void cpu_relax(void)
+{
+ asm volatile("rep; nop" ::: "memory");
+}
+
+void test_base_ipi(void)
+{
+ pthread_t pt;
+
+ uintr_received = 0;
+ if (pthread_create(&pt, NULL, &sender_thread, NULL)) {
+ printf("[FAIL]\tError creating sender thread\n");
+ return;
+ }
+
+ printf("[RUN]\tSpin in userspace (waiting for interrupts)\n");
+ // Keep spinning until interrupt received
+ while (!uintr_received)
+ cpu_relax();
+
+ printf("[OK]\tUser interrupt received\n");
+}
+
+void test_blocking_ipi(void)
+{
+ pthread_t pt;
+ long sleep_usec;
+
+ uintr_received = 0;
+ sleep_usec = 1000;
+ if (pthread_create(&pt, NULL, &sender_thread, (void *)sleep_usec)) {
+ printf("[FAIL]\tError creating sender thread\n");
+ return;
+ }
+
+ printf("[RUN]\tBlock in the kernel (waiting for interrupts)\n");
+ uintr_wait(0);
+ if (uintr_received)
+ printf("[OK]\tUser interrupt received\n");
+ else
+ printf("[FAIL]\tUser interrupt not received\n");
+}
+
+int main(int argc, char *argv[])
+{
+ receiver_setup_interrupt();
+
+ /* Enable interrupts */
+ _stui();
+
+ test_base_ipi();
+
+ test_blocking_ipi();
+
+ close(uintr_fd);
+ uintr_unregister_handler(0);
+
+ exit(EXIT_SUCCESS);
+}
--
2.33.0
