KVM: LoongArch: selftests: Add SW emulated timer test case

This test case setup one-shot timer and execute idle instruction
immediately to indicate giving up CPU, hypervisor will emulate SW
hrtimer and wakeup vCPU when SW hrtimer is fired.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/tools/testing/selftests/kvm/loongarch/arch_timer.c b/tools/testing/selftests/kvm/loongarch/arch_timer.c
index 6cc67167166319d2dbc246dcef698875ba4af73d..baa30fd296f52ec069a32ddf7a64b72436487a62 100644 (file)
--- a/tools/testing/selftests/kvm/loongarch/arch_timer.c
+++ b/tools/testing/selftests/kvm/loongarch/arch_timer.c
@@ -9,6 +9,21 @@
 #include "timer_test.h"
 #include "ucall_common.h"
 
+static void do_idle(void)
+{
+       unsigned int intid;
+       unsigned long estat;
+
+       __asm__ __volatile__("idle 0" : : : "memory");
+
+       estat = csr_read(LOONGARCH_CSR_ESTAT);
+       intid = !!(estat & BIT(INT_TI));
+
+       /* Make sure pending timer IRQ arrived */
+       GUEST_ASSERT_EQ(intid, 1);
+       csr_write(CSR_TINTCLR_TI, LOONGARCH_CSR_TINTCLR);
+}
+
 static void guest_irq_handler(struct ex_regs *regs)
 {
        unsigned int intid;
@@ -97,6 +112,30 @@ static void guest_test_oneshot_timer(uint32_t cpu)
        }
 }
 
+static void guest_test_emulate_timer(uint32_t cpu)
+{
+       uint32_t config_iter;
+       uint64_t xcnt_diff_us, us;
+       struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+       local_irq_disable();
+       shared_data->nr_iter = 0;
+       us = msecs_to_usecs(test_args.timer_period_ms);
+       for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
+               shared_data->xcnt = timer_get_cycles();
+
+               /* Setup the next interrupt */
+               timer_set_next_cmp_ms(test_args.timer_period_ms, false);
+               do_idle();
+
+               xcnt_diff_us = cycles_to_usec(timer_get_cycles() - shared_data->xcnt);
+               __GUEST_ASSERT(xcnt_diff_us >= us,
+                               "xcnt_diff_us = 0x%lx, us = 0x%lx.\n",
+                               xcnt_diff_us, us);
+       }
+       local_irq_enable();
+}
+
 static void guest_code(void)
 {
        uint32_t cpu = guest_get_vcpuid();
@@ -105,6 +144,7 @@ static void guest_code(void)
        local_irq_enable();
        guest_test_period_timer(cpu);
        guest_test_oneshot_timer(cpu);
+       guest_test_emulate_timer(cpu);
 
        GUEST_DONE();
 }