linux-kernel - [PATCH 6/6] KVM: LoongArch: selftests: Add SW emulated timer test

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20251031031652.4020879-1-maobibo@loongson.cn>
Date: Fri, 31 Oct 2025 11:16:52 +0800
From: Bibo Mao <maobibo@...ngson.cn>
To: Paolo Bonzini <pbonzini@...hat.com>,
	Sean Christopherson <seanjc@...gle.com>,
	Shuah Khan <shuah@...nel.org>,
	Tianrui Zhao <zhaotianrui@...ngson.cn>,
	Huacai Chen <chenhuacai@...nel.org>,
	Paul Walmsley <pjw@...nel.org>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alex@...ti.fr>
Cc: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	loongarch@...ts.linux.dev,
	linux-riscv@...ts.infradead.org
Subject: [PATCH 6/6] KVM: LoongArch: selftests: Add SW emulated timer test

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@...ngson.cn>
---
 .../selftests/kvm/loongarch/arch_timer.c      | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/tools/testing/selftests/kvm/loongarch/arch_timer.c b/tools/testing/selftests/kvm/loongarch/arch_timer.c
index 1be42ef33bf3..a30dd0414a34 100644
--- a/tools/testing/selftests/kvm/loongarch/arch_timer.c
+++ b/tools/testing/selftests/kvm/loongarch/arch_timer.c
@@ -114,6 +114,45 @@ static void guest_time_count_test(uint32_t cpu)
 	}
 }
 
+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_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();
@@ -123,6 +162,7 @@ static void guest_code(void)
 	local_irq_enable();
 	guest_test_oneshot_timer(cpu);
 	guest_test_period_timer(cpu);
+	guest_test_emulate_timer(cpu);
 
 	GUEST_DONE();
 }
-- 
2.39.3