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 | 235 ++++++++++++++++++++++++++++++++++++++++++++
x86/unittests.cfg | 5 +
3 files changed, 242 insertions(+), 1 deletion(-)
create mode 100644 x86/ipi_stress.c
diff --git a/x86/Makefile.common b/x86/Makefile.common
index ed5e5c76..8e0b6661 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -86,7 +86,8 @@ 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..185f791e
--- /dev/null
+++ b/x86/ipi_stress.c
@@ -0,0 +1,235 @@
+#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 "svm.h"
+#include "desc.h"
+#include "msr.h"
+#include "vm.h"
+#include "types.h"
+#include "alloc_page.h"
+#include "vmalloc.h"
+#include "svm_lib.h"
+
+u64 num_iterations = -1;
+
+volatile u64 *isr_counts;
+bool use_svm;
+int hlt_allowed = -1;
+
+
+static int get_random(int min, int max)
+{
+ /* TODO : use rdrand to seed an PRNG instead */
+ u64 random_value = rdtsc() >> 4;
+
+ return min + random_value % (max - min + 1);
+}
+
+static void ipi_interrupt_handler(isr_regs_t *r)
+{
+ isr_counts[smp_id()]++;
+ eoi();
+}
+
+static void wait_for_ipi(volatile u64 *count)
+{
+ u64 old_count = *count;
+ bool use_halt;
+
+ switch (hlt_allowed) {
+ case -1:
+ use_halt = get_random(0,10000) == 0;
+ break;
+ case 0:
+ use_halt = false;
+ break;
+ case 1:
+ use_halt = true;
+ break;
+ default:
+ use_halt = false;
+ break;
+ }
+
+ do {
+ if (use_halt)
+ asm volatile ("sti;hlt;cli\n");
+ else
+ asm volatile ("sti;nop;cli");
+
+ } while (old_count == *count);
+}
+
+/******************************************************************************************************/
+
+#ifdef __x86_64__
+
+static void l2_guest_wait_for_ipi(volatile u64 *count)
+{
+ wait_for_ipi(count);
+ asm volatile("vmmcall");
+}
+
+static void l2_guest_dummy(void)
+{
+ asm volatile("vmmcall");
+}
+
+static void wait_for_ipi_in_l2(volatile u64 *count, struct svm_vcpu *vcpu)
+{
+ u64 old_count = *count;
+ bool irq_on_vmentry = get_random(0,1) == 0;
+
+ vcpu->vmcb->save.rip = (ulong)l2_guest_wait_for_ipi;
+ vcpu->regs.rdi = (u64)count;
+
+ vcpu->vmcb->save.rip = irq_on_vmentry ? (ulong)l2_guest_dummy : (ulong)l2_guest_wait_for_ipi;
+
+ do {
+ if (irq_on_vmentry)
+ vcpu->vmcb->save.rflags |= X86_EFLAGS_IF;
+ else
+ vcpu->vmcb->save.rflags &= ~X86_EFLAGS_IF;
+
+ asm volatile("clgi;nop;sti");
+ // GIF is set by VMRUN
+ SVM_VMRUN(vcpu->vmcb, &vcpu->regs);
+ // GIF is cleared by VMEXIT
+ asm volatile("cli;nop;stgi");
+
+ assert(vcpu->vmcb->control.exit_code == SVM_EXIT_VMMCALL);
+
+ } while (old_count == *count);
+}
+#endif
+
+/******************************************************************************************************/
+
+#define FIRST_TEST_VCPU 1
+
+static void vcpu_init(void *data)
+{
+ /* To make it easier to see iteration number in the trace */
+ handle_irq(0x40, ipi_interrupt_handler);
+ handle_irq(0x50, ipi_interrupt_handler);
+}
+
+static void vcpu_code(void *data)
+{
+ int ncpus = cpu_count();
+ int cpu = (long)data;
+#ifdef __x86_64__
+ struct svm_vcpu vcpu;
+#endif
+
+ u64 i;
+
+#ifdef __x86_64__
+ if (cpu == 2 && use_svm)
+ svm_vcpu_init(&vcpu);
+#endif
+
+ assert(cpu != 0);
+
+ if (cpu != FIRST_TEST_VCPU)
+ wait_for_ipi(&isr_counts[cpu]);
+
+ for (i = 0; i < num_iterations; i++)
+ {
+ u8 physical_dst = cpu == ncpus -1 ? 1 : cpu + 1;
+
+ // 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),
+ physical_dst);
+
+ if (i == (num_iterations - 1) && cpu != FIRST_TEST_VCPU)
+ break;
+
+#ifdef __x86_64__
+ // wait for the IPI interrupt chain to come back to us
+ if (cpu == 2 && use_svm) {
+ wait_for_ipi_in_l2(&isr_counts[cpu], &vcpu);
+ continue;
+ }
+#endif
+ wait_for_ipi(&isr_counts[cpu]);
+ }
+}
+
+int main(int argc, void** argv)
+{
+ int cpu, ncpus = cpu_count();
+
+ assert(ncpus > 2);
+
+ if (argc > 1)
+ hlt_allowed = atol(argv[1]);
+
+ if (argc > 2)
+ num_iterations = atol(argv[2]);
+
+ setup_vm();
+
+#ifdef __x86_64__
+ if (svm_supported()) {
+ use_svm = true;
+ setup_svm();
+ }
+#endif
+
+ isr_counts = (volatile u64 *)calloc(ncpus, sizeof(u64));
+
+ printf("found %d cpus\n", ncpus);
+ printf("running for %lld iterations - test\n",
+ (long long unsigned int)num_iterations);
+
+
+ for (cpu = 0; cpu < ncpus; ++cpu)
+ on_cpu_async(cpu, vcpu_init, (void *)(long)cpu);
+
+ /* now let all the vCPUs end the IPI function*/
+ while (cpus_active() > 1)
+ pause();
+
+ printf("starting test on all cpus but 0...\n");
+
+ for (cpu = ncpus-1; cpu >= FIRST_TEST_VCPU; cpu--)
+ on_cpu_async(cpu, vcpu_code, (void *)(long)cpu);
+
+ printf("test started, waiting to end...\n");
+
+ while (cpus_active() > 1) {
+
+ unsigned long isr_count1, isr_count2;
+
+ isr_count1 = isr_counts[1];
+ delay(5ULL*1000*1000*1000);
+ isr_count2 = isr_counts[1];
+
+ if (isr_count1 == isr_count2) {
+ printf("\n");
+ printf("hang detected!!\n");
+ break;
+ } else {
+ printf("made %ld IPIs \n", (isr_count2 - isr_count1)*(ncpus-1));
+ }
+ }
+
+ printf("\n");
+
+ for (cpu = 1; cpu < ncpus; ++cpu)
+ report(isr_counts[cpu] == num_iterations,
+ "Number of IPIs match (%lld)",
+ (long long unsigned int)isr_counts[cpu]);
+
+ free((void*)isr_counts);
+ return report_summary();
+}
diff --git a/x86/unittests.cfg b/x86/unittests.cfg
index ebb3fdfc..7655d2ba 100644
--- a/x86/unittests.cfg
+++ b/x86/unittests.cfg
@@ -61,6 +61,11 @@ smp = 2
file = smptest.flat
smp = 3
+[ipi_stress]
+file = ipi_stress.flat
+extra_params = -cpu host,-x2apic,-svm,-hypervisor -global kvm-pit.lost_tick_policy=discard -machine kernel-irqchip=on -append '0 50000'
+smp = 4
+
[vmexit_cpuid]
file = vmexit.flat
extra_params = -append 'cpuid'
--
2.26.3
