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Message-Id: <20251031031612.4020839-1-maobibo@loongson.cn>
Date: Fri, 31 Oct 2025 11:16:12 +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 4/6] KVM: LoongArch: selftests: Add timer test case with one-shot mode
Add timer test case based on common arch_timer code, one-shot mode
is tested with timer interrupt.
Signed-off-by: Bibo Mao <maobibo@...ngson.cn>
---
tools/testing/selftests/kvm/Makefile.kvm | 10 +-
.../kvm/include/loongarch/arch_timer.h | 79 +++++++++++++++
.../kvm/include/loongarch/processor.h | 10 ++
.../selftests/kvm/lib/loongarch/processor.c | 4 +-
.../selftests/kvm/loongarch/arch_timer.c | 98 +++++++++++++++++++
5 files changed, 196 insertions(+), 5 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/loongarch/arch_timer.h
create mode 100644 tools/testing/selftests/kvm/loongarch/arch_timer.c
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 148d427ff24b..662adf8f309b 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -183,6 +183,8 @@ TEST_GEN_PROGS_arm64 += memslot_perf_test
TEST_GEN_PROGS_arm64 += mmu_stress_test
TEST_GEN_PROGS_arm64 += rseq_test
TEST_GEN_PROGS_arm64 += steal_time
+SPLIT_TESTS_arm64 += arch_timer
+SPLIT_TESTS_arm64 += get-reg-list
TEST_GEN_PROGS_s390 = $(TEST_GEN_PROGS_COMMON)
TEST_GEN_PROGS_s390 += s390/memop
@@ -209,6 +211,8 @@ TEST_GEN_PROGS_riscv += memslot_perf_test
TEST_GEN_PROGS_riscv += mmu_stress_test
TEST_GEN_PROGS_riscv += rseq_test
TEST_GEN_PROGS_riscv += steal_time
+SPLIT_TESTS_riscv += arch_timer
+SPLIT_TESTS_riscv += get-reg-list
TEST_GEN_PROGS_loongarch += coalesced_io_test
TEST_GEN_PROGS_loongarch += demand_paging_test
@@ -222,10 +226,10 @@ TEST_GEN_PROGS_loongarch += kvm_page_table_test
TEST_GEN_PROGS_loongarch += memslot_modification_stress_test
TEST_GEN_PROGS_loongarch += memslot_perf_test
TEST_GEN_PROGS_loongarch += set_memory_region_test
+TEST_GEN_PROGS_loongarch += arch_timer
+SPLIT_TESTS_loongarch = arch_timer
-SPLIT_TESTS += arch_timer
-SPLIT_TESTS += get-reg-list
-
+SPLIT_TESTS += $(SPLIT_TESTS_$(ARCH))
TEST_PROGS += $(TEST_PROGS_$(ARCH))
TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(ARCH))
TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(ARCH))
diff --git a/tools/testing/selftests/kvm/include/loongarch/arch_timer.h b/tools/testing/selftests/kvm/include/loongarch/arch_timer.h
new file mode 100644
index 000000000000..94b1cba2744d
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/loongarch/arch_timer.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * LoongArch Constant Timer specific interface
+ */
+#ifndef SELFTEST_KVM_ARCH_TIMER_H
+#define SELFTEST_KVM_ARCH_TIMER_H
+
+#include "processor.h"
+/* LoongArch timer frequency is constant 100MHZ */
+#define TIMER_FREQ (100UL << 20)
+#define msec_to_cycles(msec) (TIMER_FREQ * (unsigned long)(msec) / 1000)
+#define usec_to_cycles(usec) (TIMER_FREQ * (unsigned long)(usec) / 1000000)
+#define cycles_to_usec(cycles) ((unsigned long)(cycles) * 1000000 / TIMER_FREQ)
+
+static inline unsigned long timer_get_cycles(void)
+{
+ unsigned long val = 0;
+
+ __asm__ __volatile__(
+ "rdtime.d %0, $zero\n\t"
+ : "=r"(val)
+ :
+ );
+
+ return val;
+}
+
+static inline void timer_set_next_cmp_ms(unsigned int msec, bool period)
+{
+ unsigned long val;
+
+ val = msec_to_cycles(msec) & CSR_TCFG_VAL;
+ val |= CSR_TCFG_EN;
+ if (period)
+ val |= CSR_TCFG_PERIOD;
+ csr_write(val, LOONGARCH_CSR_TCFG);
+}
+
+static inline unsigned long timer_get_val(void)
+{
+ return csr_read(LOONGARCH_CSR_TVAL);
+}
+
+static inline unsigned long timer_get_cfg(void)
+{
+ return csr_read(LOONGARCH_CSR_TCFG);
+}
+
+static inline void timer_irq_enable(void)
+{
+ unsigned long val;
+
+ val = csr_read(LOONGARCH_CSR_ECFG);
+ val |= ECFGF_TIMER;
+ csr_write(val, LOONGARCH_CSR_ECFG);
+}
+
+static inline void timer_irq_disable(void)
+{
+ unsigned long val;
+
+ val = csr_read(LOONGARCH_CSR_ECFG);
+ val &= ~ECFGF_TIMER;
+ csr_write(val, LOONGARCH_CSR_ECFG);
+}
+
+static inline void __delay(uint64_t cycles)
+{
+ uint64_t start = timer_get_cycles();
+
+ while ((timer_get_cycles() - start) < cycles)
+ cpu_relax();
+}
+
+static inline void udelay(unsigned long usec)
+{
+ __delay(usec_to_cycles(usec));
+}
+#endif /* SELFTEST_KVM_ARCH_TIMER_H */
diff --git a/tools/testing/selftests/kvm/include/loongarch/processor.h b/tools/testing/selftests/kvm/include/loongarch/processor.h
index b027f8f4dac7..61f6e215046b 100644
--- a/tools/testing/selftests/kvm/include/loongarch/processor.h
+++ b/tools/testing/selftests/kvm/include/loongarch/processor.h
@@ -83,6 +83,8 @@
#define LOONGARCH_CSR_PRMD 0x1
#define LOONGARCH_CSR_EUEN 0x2
#define LOONGARCH_CSR_ECFG 0x4
+#define ECFGB_TIMER 11
+#define ECFGF_TIMER (BIT_ULL(ECFGB_TIMER))
#define LOONGARCH_CSR_ESTAT 0x5 /* Exception status */
#define CSR_ESTAT_EXC_SHIFT 16
#define CSR_ESTAT_EXC_WIDTH 6
@@ -111,6 +113,14 @@
#define LOONGARCH_CSR_KS1 0x31
#define LOONGARCH_CSR_TMID 0x40
#define LOONGARCH_CSR_TCFG 0x41
+#define CSR_TCFG_VAL (BIT_ULL(48) - BIT_ULL(2))
+#define CSR_TCFG_PERIOD_SHIFT 1
+#define CSR_TCFG_PERIOD (0x1UL << CSR_TCFG_PERIOD_SHIFT)
+#define CSR_TCFG_EN (0x1UL)
+#define LOONGARCH_CSR_TVAL 0x42
+#define LOONGARCH_CSR_TINTCLR 0x44 /* Timer interrupt clear */
+#define CSR_TINTCLR_TI_SHIFT 0
+#define CSR_TINTCLR_TI (1 << CSR_TINTCLR_TI_SHIFT)
/* TLB refill exception entry */
#define LOONGARCH_CSR_TLBRENTRY 0x88
#define LOONGARCH_CSR_TLBRSAVE 0x8b
diff --git a/tools/testing/selftests/kvm/lib/loongarch/processor.c b/tools/testing/selftests/kvm/lib/loongarch/processor.c
index 20ba476ccb72..436990258068 100644
--- a/tools/testing/selftests/kvm/lib/loongarch/processor.c
+++ b/tools/testing/selftests/kvm/lib/loongarch/processor.c
@@ -271,8 +271,8 @@ static void loongarch_vcpu_setup(struct kvm_vcpu *vcpu)
TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
}
- /* user mode and page enable mode */
- val = PLV_USER | CSR_CRMD_PG;
+ /* kernel mode and page enable mode */
+ val = PLV_KERN | CSR_CRMD_PG;
loongarch_set_csr(vcpu, LOONGARCH_CSR_CRMD, val);
loongarch_set_csr(vcpu, LOONGARCH_CSR_PRMD, val);
loongarch_set_csr(vcpu, LOONGARCH_CSR_EUEN, 1);
diff --git a/tools/testing/selftests/kvm/loongarch/arch_timer.c b/tools/testing/selftests/kvm/loongarch/arch_timer.c
new file mode 100644
index 000000000000..2a2cebcf3885
--- /dev/null
+++ b/tools/testing/selftests/kvm/loongarch/arch_timer.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * The test validates one-shot constant timer IRQ using CSR_TCFG and
+ * CSR_TVAL registers.
+ */
+#include "arch_timer.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "timer_test.h"
+#include "ucall_common.h"
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+ uint64_t xcnt, val, cfg, xcnt_diff_us;
+ unsigned int intid;
+ uint32_t cpu = guest_get_vcpuid();
+ struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+ intid = !!(regs->estat & BIT(INT_TI));
+
+ /* Make sure we are dealing with the correct timer IRQ */
+ GUEST_ASSERT_EQ(intid, 1);
+
+ cfg = timer_get_cfg();
+
+ /*
+ * On physical machine, value of LOONGARCH_CSR_TVAL is BIT_ULL(48) - 1
+ * On virtual machine, its value counts down from BIT_ULL(48) - 1
+ */
+ val = timer_get_val();
+ xcnt = timer_get_cycles();
+ xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
+
+ /* Basic 'timer condition met' check */
+ __GUEST_ASSERT(val > cfg,
+ "val = 0x%lx, cfg = 0x%lx, xcnt_diff_us = 0x%lx",
+ val, cfg, xcnt_diff_us);
+
+ csr_write(CSR_TINTCLR_TI, LOONGARCH_CSR_TINTCLR);
+ WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
+}
+
+static void guest_test_oneshot_timer(uint32_t cpu)
+{
+ uint32_t irq_iter, config_iter;
+ uint64_t us;
+ struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
+
+ shared_data->nr_iter = 0;
+ shared_data->guest_stage = 0;
+ us = msecs_to_usecs(test_args.timer_period_ms) + test_args.timer_err_margin_us;
+ 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);
+ /* Setup a timeout for the interrupt to arrive */
+ udelay(us);
+
+ irq_iter = READ_ONCE(shared_data->nr_iter);
+ __GUEST_ASSERT(config_iter + 1 == irq_iter,
+ "config_iter + 1 = 0x%x, irq_iter = 0x%x.\n"
+ " Guest timer interrupt was not triggered within the specified\n"
+ " interval, try to increase the error margin by [-e] option.\n",
+ config_iter + 1, irq_iter);
+ }
+}
+
+static void guest_code(void)
+{
+ uint32_t cpu = guest_get_vcpuid();
+
+ timer_irq_enable();
+ local_irq_enable();
+ guest_test_oneshot_timer(cpu);
+
+ GUEST_DONE();
+}
+
+struct kvm_vm *test_vm_create(void)
+{
+ struct kvm_vm *vm;
+ int nr_vcpus = test_args.nr_vcpus;
+
+ vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
+ vm_init_descriptor_tables(vm);
+ vm_install_exception_handler(vm, EXCCODE_INT, guest_irq_handler);
+
+ /* Make all the test's cmdline args visible to the guest */
+ sync_global_to_guest(vm, test_args);
+ return vm;
+}
+
+void test_vm_cleanup(struct kvm_vm *vm)
+{
+ kvm_vm_free(vm);
+}
--
2.39.3
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