Adds a test that sends IPIs between vCPUs and detects missing IPIs
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
x86/Makefile.common | 3 +-
x86/ipi_stress.c | 167 ++++++++++++++++++++++++++++++++++++++++++++
x86/unittests.cfg | 10 +++
3 files changed, 179 insertions(+), 1 deletion(-)
create mode 100644 x86/ipi_stress.c
diff --git a/x86/Makefile.common b/x86/Makefile.common
index fa0a50e6..08cc036b 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -89,7 +89,8 @@ tests-common = $(TEST_DIR)/vmexit.$(exe) $(TEST_DIR)/tsc.$(exe) \
$(TEST_DIR)/eventinj.$(exe) \
$(TEST_DIR)/smap.$(exe) \
$(TEST_DIR)/umip.$(exe) \
- $(TEST_DIR)/smm_int_window.$(exe)
+ $(TEST_DIR)/smm_int_window.$(exe) \
+ $(TEST_DIR)/ipi_stress.$(exe)
# The following test cases are disabled when building EFI tests because they
# use absolute addresses in their inline assembly code, which cannot compile
diff --git a/x86/ipi_stress.c b/x86/ipi_stress.c
new file mode 100644
index 00000000..dea3e605
--- /dev/null
+++ b/x86/ipi_stress.c
@@ -0,0 +1,167 @@
+#include "libcflat.h"
+#include "smp.h"
+#include "alloc.h"
+#include "apic.h"
+#include "processor.h"
+#include "isr.h"
+#include "asm/barrier.h"
+#include "delay.h"
+#include "desc.h"
+#include "msr.h"
+#include "vm.h"
+#include "types.h"
+#include "alloc_page.h"
+#include "vmalloc.h"
+#include "random.h"
+
+u64 num_iterations = 100000;
+float hlt_prob = 0.1;
+volatile bool end_test;
+
+#define APIC_TIMER_PERIOD (1000*1000*1000)
+
+struct cpu_test_state {
+ volatile u64 isr_count;
+ u64 last_isr_count;
+ struct random_state random;
+ int smp_id;
+} *cpu_states;
+
+
+static void ipi_interrupt_handler(isr_regs_t *r)
+{
+ cpu_states[smp_id()].isr_count++;
+ eoi();
+}
+
+static void local_timer_interrupt(isr_regs_t *r)
+{
+ struct cpu_test_state *state = &cpu_states[smp_id()];
+
+ u64 isr_count = state->isr_count;
+ unsigned long diff = isr_count - state->last_isr_count;
+
+ if (!diff) {
+ printf("\n");
+ printf("hang detected!!\n");
+ end_test = true;
+ goto out;
+ }
+
+ printf("made %ld IPIs\n", diff * cpu_count());
+ state->last_isr_count = state->isr_count;
+out:
+ eoi();
+}
+
+static void wait_for_ipi(struct cpu_test_state *state)
+{
+ u64 old_count = state->isr_count;
+ bool use_halt = random_decision(&state->random, hlt_prob);
+
+ do {
+ if (use_halt) {
+ safe_halt();
+ cli();
+ } else
+ sti_nop_cli();
+
+ } while (old_count == state->isr_count);
+
+ assert(state->isr_count == old_count + 1);
+}
+
+
+static void vcpu_init(void *)
+{
+ struct cpu_test_state *state = &cpu_states[smp_id()];
+
+ memset(state, 0, sizeof(*state));
+
+ /* To make it easier to see iteration number in the trace */
+ handle_irq(0x40, ipi_interrupt_handler);
+ handle_irq(0x50, ipi_interrupt_handler);
+
+ state->random = get_prng();
+ state->isr_count = 0;
+ state->smp_id = smp_id();
+}
+
+static void vcpu_code(void *)
+{
+ struct cpu_test_state *state = &cpu_states[smp_id()];
+ int ncpus = cpu_count();
+ u64 i;
+ u8 target_smp_id;
+
+ if (state->smp_id > 0)
+ wait_for_ipi(state);
+
+ target_smp_id = state->smp_id == ncpus - 1 ? 0 : state->smp_id + 1;
+
+ for (i = 0; i < num_iterations && !end_test; i++) {
+ // send IPI to a next vCPU in a circular fashion
+ apic_icr_write(APIC_INT_ASSERT |
+ APIC_DEST_PHYSICAL |
+ APIC_DM_FIXED |
+ (i % 2 ? 0x40 : 0x50),
+ target_smp_id);
+
+ if (i == (num_iterations - 1) && state->smp_id > 0)
+ break;
+
+ // wait for the IPI interrupt chain to come back to us
+ wait_for_ipi(state);
+ }
+}
+
+int main(int argc, void **argv)
+{
+ int cpu, ncpus = cpu_count();
+
+ handle_irq(0xF0, local_timer_interrupt);
+ apic_setup_timer(0xF0, APIC_LVT_TIMER_PERIODIC);
+
+ if (argc > 1) {
+ int hlt_param = atol(argv[1]);
+
+ if (hlt_param == 1)
+ hlt_prob = 100;
+ else if (hlt_param == 0)
+ hlt_prob = 0;
+ }
+
+ if (argc > 2)
+ num_iterations = atol(argv[2]);
+
+ setup_vm();
+ init_prng();
+
+ cpu_states = calloc(ncpus, sizeof(cpu_states[0]));
+
+ printf("found %d cpus\n", ncpus);
+ printf("running for %lld iterations\n",
+ (unsigned long long)num_iterations);
+
+ on_cpus(vcpu_init, NULL);
+
+ apic_start_timer(1000*1000*1000);
+
+ printf("test started, waiting to end...\n");
+
+ on_cpus(vcpu_code, NULL);
+
+ apic_stop_timer();
+ apic_cleanup_timer();
+
+ for (cpu = 0; cpu < ncpus; ++cpu) {
+ u64 result = cpu_states[cpu].isr_count;
+
+ report(result == num_iterations,
+ "Number of IPIs match (%lld)",
+ (unsigned long long)result);
+ }
+
+ free((void *)cpu_states);
+ return report_summary();
+}
diff --git a/x86/unittests.cfg b/x86/unittests.cfg
index df248dff..b0fd92fb 100644
--- a/x86/unittests.cfg
+++ b/x86/unittests.cfg
@@ -74,6 +74,16 @@ smp = 2
file = smptest.flat
smp = 3
+[ipi_stress]
+file = ipi_stress.flat
+extra_params = -cpu host,-x2apic -global kvm-pit.lost_tick_policy=discard -machine kernel-irqchip=on
+smp = 4
+
+[ipi_stress_x2apic]
+file = ipi_stress.flat
+extra_params = -cpu host,+x2apic -global kvm-pit.lost_tick_policy=discard -machine kernel-irqchip=on
+smp = 4
+
[vmexit_cpuid]
file = vmexit.flat
extra_params = -append 'cpuid'
--
2.34.3
