Re: [kvm-unit-tests PATCH v3 11/14] arm/arm64: ITS: INT functional tests

[Andrew Jones]

On Tue, Jan 28, 2020 at 11:34:56AM +0100, Eric Auger wrote:
> Triggers LPIs through the INT command.
> 
> the test checks the LPI hits the right CPU and triggers
> the right LPI intid, ie. the translation is correct.
> 
> Updates to the config table also are tested, along with inv
> and invall commands.
> 
> Signed-off-by: Eric Auger <address@hidden>
> 
> ---
> 
> v2 -> v3:
> - add comments
> - keep the report_skip in case there aren't 4 vcpus to be able to
>   run other tests in the its category.
> - fix the prefix pop
> - move its_event and its_stats to arm/gic.c
> ---
>  arm/gic.c         | 228 +++++++++++++++++++++++++++++++++++++++++++---
>  arm/unittests.cfg |   7 ++
>  2 files changed, 224 insertions(+), 11 deletions(-)
> 
> diff --git a/arm/gic.c b/arm/gic.c
> index 4d7dd03..50104b1 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -160,6 +160,87 @@ static void ipi_handler(struct pt_regs *regs __unused)
>       }
>  }
>  
> +static void setup_irq(handler_t handler)
> +{
> +     gic_enable_defaults();
> +#ifdef __arm__
> +     install_exception_handler(EXCPTN_IRQ, handler);
> +#else
> +     install_irq_handler(EL1H_IRQ, handler);
> +#endif
> +     local_irq_enable();
> +}
> +
> +#if defined(__aarch64__)
> +struct its_event {
> +     int cpu_id;
> +     int lpi_id;
> +};
> +
> +struct its_stats {
> +     struct its_event expected;
> +     struct its_event observed;
> +};
> +
> +static struct its_stats lpi_stats;
> +
> +static void lpi_handler(struct pt_regs *regs __unused)
> +{
> +     u32 irqstat = gic_read_iar();
> +     int irqnr = gic_iar_irqnr(irqstat);
> +
> +     gic_write_eoir(irqstat);
> +     if (irqnr < 8192)
> +             report(false, "Unexpected non LPI interrupt received");

report_info

> +     smp_rmb(); /* pairs with wmb in lpi_stats_expect */
> +     lpi_stats.observed.cpu_id = smp_processor_id();
> +     lpi_stats.observed.lpi_id = irqnr;
> +     smp_wmb(); /* pairs with rmb in check_lpi_stats */
> +}
> +
> +static void lpi_stats_expect(int exp_cpu_id, int exp_lpi_id)
> +{
> +     lpi_stats.expected.cpu_id = exp_cpu_id;
> +     lpi_stats.expected.lpi_id = exp_lpi_id;
> +     lpi_stats.observed.cpu_id = -1;
> +     lpi_stats.observed.lpi_id = -1;
> +     smp_wmb(); /* pairs with rmb in handler */
> +}
> +
> +static void check_lpi_stats(void)

static void check_lpi_stats(const char *testname)
{
   bool pass = false;

> +{
> +     mdelay(100);
> +     smp_rmb(); /* pairs with wmb in lpi_handler */
> +     if ((lpi_stats.observed.cpu_id != lpi_stats.expected.cpu_id) ||
> +         (lpi_stats.observed.lpi_id != lpi_stats.expected.lpi_id)) {

nit: extra ()

> +             if (lpi_stats.observed.cpu_id == -1 &&
> +                 lpi_stats.observed.lpi_id == -1) {
> +                     report(false,
> +                            "No LPI received whereas (cpuid=%d, intid=%d) "
> +                            "was expected", lpi_stats.expected.cpu_id,
> +                            lpi_stats.expected.lpi_id);

report_info

> +             } else {
> +                     report(false, "Unexpected LPI (cpuid=%d, intid=%d)",
> +                            lpi_stats.observed.cpu_id,
> +                            lpi_stats.observed.lpi_id);

report_info

> +             }

pass = false;

> +     } else if (lpi_stats.expected.lpi_id != -1) {
> +             report(true, "LPI %d on CPU %d", lpi_stats.observed.lpi_id,
> +                    lpi_stats.observed.cpu_id);

report_info

> +     } else {
> +             report(true, "no LPI received, as expected");

report_info


> +     }

report(pass, "%s", testname);

> +}
> +
> +static void secondary_lpi_test(void)
> +{
> +     setup_irq(lpi_handler);
> +     cpumask_set_cpu(smp_processor_id(), &ready);
> +     while (1)
> +             wfi();
> +}
> +#endif
> +
>  static void gicv2_ipi_send_self(void)
>  {
>       writel(2 << 24 | IPI_IRQ, gicv2_dist_base() + GICD_SGIR);
> @@ -217,17 +298,6 @@ static void ipi_test_smp(void)
>       report_prefix_pop();
>  }
>  
> -static void setup_irq(handler_t handler)
> -{
> -     gic_enable_defaults();
> -#ifdef __arm__
> -     install_exception_handler(EXCPTN_IRQ, handler);
> -#else
> -     install_irq_handler(EL1H_IRQ, handler);
> -#endif
> -     local_irq_enable();
> -}
> -
>  static void ipi_send(void)
>  {
>       setup_irq(ipi_handler);
> @@ -522,6 +592,7 @@ static void gic_test_mmio(void)
>  #if defined(__arm__)
>  
>  static void test_its_introspection(void) {}
> +static void test_its_trigger(void) {}
>  
>  #else /* __arch64__ */
>  
> @@ -561,6 +632,137 @@ static void test_its_introspection(void)
>       report_info("collection baser entry_size = 0x%x", coll_baser->esz);
>  }
>  
> +static bool its_prerequisites(int nb_cpus)
> +{
> +     int cpu;
> +
> +     if (!gicv3_its_base()) {
> +             report_skip("No ITS, skip ...");
> +             return true;
> +     }
> +
> +     if (nr_cpus < 4) {

nr_cpus < nb_cpus, or just drop the nb_cpus parameter and hard code 4
here.

> +             report_skip("Test requires at least %d vcpus", nb_cpus);
> +             return true;
> +     }
> +
> +     stats_reset();
> +
> +     setup_irq(lpi_handler);
> +
> +     for_each_present_cpu(cpu) {
> +             if (cpu == 0)
> +                     continue;
> +             smp_boot_secondary(cpu, secondary_lpi_test);
> +     }
> +     wait_on_ready();
> +
> +     its_enable_defaults();
> +
> +     lpi_stats_expect(-1, -1);
> +     check_lpi_stats();
> +
> +     return false;

Reverse logic. I'd expect 'return true' for success.

> +}
> +
> +static void test_its_trigger(void)
> +{
> +     struct its_collection *col3, *col2;
> +     struct its_device *dev2, *dev7;
> +
> +     if (its_prerequisites(4))

if (!its_prerequisites(...))

> +             return;
> +
> +     dev2 = its_create_device(2 /* dev id */, 8 /* nb_ites */);
> +     dev7 = its_create_device(7 /* dev id */, 8 /* nb_ites */);
> +
> +     col3 = its_create_collection(3 /* col id */, 3/* target PE */);
> +     col2 = its_create_collection(2 /* col id */, 2/* target PE */);
> +
> +     gicv3_lpi_set_config(8195, LPI_PROP_DEFAULT);
> +     gicv3_lpi_set_config(8196, LPI_PROP_DEFAULT);
> +
> +     its_send_invall(col2);
> +     its_send_invall(col3);
> +
> +     report_prefix_push("int");
> +     /*
> +      * dev=2, eventid=20  -> lpi= 8195, col=3
> +      * dev=7, eventid=255 -> lpi= 8196, col=2
> +      * Trigger dev2, eventid=20 and dev7, eventid=255
> +      * Check both LPIs hit
> +      */
> +
> +     its_send_mapd(dev2, true);
> +     its_send_mapd(dev7, true);
> +
> +     its_send_mapc(col3, true);
> +     its_send_mapc(col2, true);
> +
> +     its_send_mapti(dev2, 8195 /* lpi id */,
> +                    20 /* event id */, col3);
> +     its_send_mapti(dev7, 8196 /* lpi id */,
> +                    255 /* event id */, col2);

No need for line breaks, with the embedded comments it's hard to read

> +
> +     lpi_stats_expect(3, 8195);
> +     its_send_int(dev2, 20);
> +     check_lpi_stats();
> +
> +     lpi_stats_expect(2, 8196);
> +     its_send_int(dev7, 255);
> +     check_lpi_stats();
> +
> +     report_prefix_pop();

I think a table of parameters and loop would be nicer than all the
repeated function calls.

> +
> +     report_prefix_push("inv/invall");
> +
> +     /*
> +      * disable 8195, check dev2/eventid=20 does not trigger the
> +      * corresponding LPI
> +      */
> +     gicv3_lpi_set_config(8195, LPI_PROP_DEFAULT & ~0x1);

LPI_PROP_DEFAULT & ~LPI_PROP_ENABLED

> +     its_send_inv(dev2, 20);
> +
> +     lpi_stats_expect(-1, -1);
> +     its_send_int(dev2, 20);
> +     check_lpi_stats();
> +
> +     /*
> +      * re-enable the LPI but willingly do not call invall
> +      * so the change in config is not taken into account.
> +      * The LPI should not hit
> +      */
> +     gicv3_lpi_set_config(8195, LPI_PROP_DEFAULT);
> +     lpi_stats_expect(-1, -1);
> +     its_send_int(dev2, 20);
> +     check_lpi_stats();
> +
> +     /* Now call the invall and check the LPI hits */
> +     its_send_invall(col3);
> +     lpi_stats_expect(3, 8195);
> +     its_send_int(dev2, 20);
> +     check_lpi_stats();
> +
> +     report_prefix_pop();

Need blank line here.

> +     /*
> +      * Unmap device 2 and check the eventid 20 formerly
> +      * attached to it does not hit anymore
> +      */
> +     report_prefix_push("mapd valid=false");

Above you have the prefix-push before the comment explaining the test.
After is probably better, but whatever, as long as it's consistent.

> +     its_send_mapd(dev2, false);
> +     lpi_stats_expect(-1, -1);
> +     its_send_int(dev2, 20);
> +     check_lpi_stats();
> +     report_prefix_pop();
> +
> +     /* Unmap the collection this time and check no LPI does hit */
> +     report_prefix_push("mapc valid=false");
> +     its_send_mapc(col2, false);
> +     lpi_stats_expect(-1, -1);
> +     its_send_int(dev7, 255);
> +     check_lpi_stats();
> +     report_prefix_pop();
> +}
>  #endif
>  
>  int main(int argc, char **argv)
> @@ -594,6 +796,10 @@ int main(int argc, char **argv)
>               report_prefix_push(argv[1]);
>               gic_test_mmio();
>               report_prefix_pop();
> +     } else if (!strcmp(argv[1], "its-trigger")) {
> +             report_prefix_push(argv[1]);
> +             test_its_trigger();
> +             report_prefix_pop();
>       } else if (strcmp(argv[1], "its-introspection") == 0) {
>               report_prefix_push(argv[1]);
>               test_its_introspection();
> diff --git a/arm/unittests.cfg b/arm/unittests.cfg
> index ba2b31b..bfafec5 100644
> --- a/arm/unittests.cfg
> +++ b/arm/unittests.cfg
> @@ -129,6 +129,13 @@ extra_params = -machine gic-version=3 -append 
> 'its-introspection'
>  groups = its
>  arch = arm64
>  
> +[its-trigger]
> +file = gic.flat
> +smp = $MAX_SMP
> +extra_params = -machine gic-version=3 -append 'its-trigger'
> +groups = its
> +arch = arm64
> +
>  # Test PSCI emulation
>  [psci]
>  file = psci.flat
> -- 
> 2.20.1
>

Thanks,
drew