Re: [kvm-unit-tests PATCH v3 14/14] arm/arm64: ITS: pending table migration test

[Auger Eric <eric.auger@redhat.com>]

Hi Drew,

On 2/7/20 3:06 PM, Andrew Jones wrote:
> On Tue, Jan 28, 2020 at 11:34:59AM +0100, Eric Auger wrote:
>> Add two new migration tests. One testing the migration of
>> a topology where collection were unmapped. The second test
>> checks the migration of the pending table.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> v2 -> v3:
>> - tests belong to both its and migration groups
>> ---
>>  arm/gic.c         | 150 ++++++++++++++++++++++++++++++++++++++++++++++
>>  arm/unittests.cfg |  16 +++++
>>  2 files changed, 166 insertions(+)
>>
>> diff --git a/arm/gic.c b/arm/gic.c
>> index fa8626a..ec3dd3a 100644
>> --- a/arm/gic.c
>> +++ b/arm/gic.c
>> @@ -195,6 +195,7 @@ static void lpi_handler(struct pt_regs *regs __unused)
>>  	smp_rmb(); /* pairs with wmb in lpi_stats_expect */
>>  	lpi_stats.observed.cpu_id = smp_processor_id();
>>  	lpi_stats.observed.lpi_id = irqnr;
>> +	acked[lpi_stats.observed.cpu_id]++;
>>  	smp_wmb(); /* pairs with rmb in check_lpi_stats */
>>  }
>>  
>> @@ -239,6 +240,18 @@ static void secondary_lpi_test(void)
>>  	while (1)
>>  		wfi();
>>  }
>> +
>> +static void check_lpi_hits(int *expected)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < nr_cpus; i++) {
>> +		if (acked[i] != expected[i])
>> +			report(false, "expected %d LPIs on PE #%d, %d observed",
>> +			       expected[i], i, acked[i]);
> 
> report_info
> pass = false
> 
>> +		}
>> +	report(true, "check LPI on all vcpus");
> 
> report(pass, ...);
I still don't get the issue.
> 
>> +}
>>  #endif
>>  
>>  static void gicv2_ipi_send_self(void)
>> @@ -594,6 +607,8 @@ static void gic_test_mmio(void)
>>  static void test_its_introspection(void) {}
>>  static void test_its_trigger(void) {}
>>  static void test_its_migration(void) {}
>> +static void test_migrate_unmapped_collection(void) {}
>> +static void test_its_pending_migration(void) {}
> 
> I'm not sure what's worse. This pile of stubs or one #ifdef in main()
> wrapping all the calls.
Those stubs now are in the arm header.
> 
>>  
>>  #else /* __arch64__ */
>>  
>> @@ -666,6 +681,18 @@ static bool its_prerequisites(int nb_cpus)
>>  	return false;
>>  }
>>  
>> +static void set_lpi(struct its_device *dev, u32 eventid, u32 physid,
>> +		    struct its_collection *col)
>> +{
>> +	if (!dev || !col)
> 
> I don't think col can be null, and this doesn't look like the right place
> to check if dev is null.  If we're bothiner to call set_lpi, then I
> think we should already expect dev to be good to go.
put an assert() instead
> 
>> +		report_abort("wrong device or collection");
>> +
>> +	its_send_mapti(dev, physid, eventid, col);
>> +
>> +	gicv3_lpi_set_config(physid, LPI_PROP_DEFAULT);
>> +	its_send_invall(col);
>> +}
>> +
>>  /*
>>   * Setup the configuration for those mappings:
>>   * dev_id=2 event=20 -> vcpu 3, intid=8195
>> @@ -806,6 +833,121 @@ static void test_its_migration(void)
>>  	its_send_int(dev7, 255);
>>  	check_lpi_stats();
>>  }
>> +
>> +static void test_migrate_unmapped_collection(void)
>> +{
>> +	struct its_collection *col;
>> +	struct its_device *dev2, *dev7;
>> +	u8 config;
>> +
>> +	if (its_setup1())
>> +		return;
>> +
>> +	col = its_create_collection(nr_cpus - 1, nr_cpus - 1);
>> +	dev2 = its_get_device(2);
>> +	dev7 = its_get_device(7);
>> +
>> +	/* MAPTI with the collection unmapped */
>> +	set_lpi(dev2, 0, 8192, col);
>> +
>> +	puts("Now migrate the VM, then press a key to continue...\n");
>> +	(void)getchar();
>> +	report(true, "Migration complete");
> 
> report_info
yep
> 
>> +
>> +	/* on the destination, map the collection */
>> +	its_send_mapc(col, true);
>> +
>> +	lpi_stats_expect(2, 8196);
>> +	its_send_int(dev7, 255);
>> +	check_lpi_stats();
>> +
>> +	config = gicv3_lpi_get_config(8192);
>> +	report(config == LPI_PROP_DEFAULT,
>> +	       "Config of LPI 8192 was properly migrated");
>> +
>> +	lpi_stats_expect(nr_cpus - 1, 8192);
>> +	its_send_int(dev2, 0);
>> +	check_lpi_stats();
>> +
>> +	/* unmap the collection */
>> +	its_send_mapc(col, false);
>> +
>> +	lpi_stats_expect(-1, -1);
>> +	its_send_int(dev2, 0);
>> +	check_lpi_stats();
>> +
>> +	/* remap event 0 onto lpiid 8193 */
>> +	set_lpi(dev2, 0, 8193, col);
>> +	lpi_stats_expect(-1, -1);
>> +	its_send_int(dev2, 0);
>> +	check_lpi_stats();
>> +
>> +	/* remap the collection */
>> +	its_send_mapc(col, true);
>> +	lpi_stats_expect(nr_cpus - 1, 8193);
>> +}
>> +
>> +static void test_its_pending_migration(void)
>> +{
>> +	struct its_device *dev;
>> +	struct its_collection *collection[2];
>> +	int expected[NR_CPUS];
> 
> expected = malloc(nr_cpus * sizeof(int));
> 
> I know there are other places using NR_CPUS right now that don't have to,
> but we shouldn't add more. Eventually I'll change the other places too.
OK
> 
>> +	u64 pendbaser;
>> +	void *ptr;
>> +	int i;
>> +
>> +	if (its_prerequisites(4))
>> +		return;
>> +
>> +	dev = its_create_device(2 /* dev id */, 8 /* nb_ites */);
>> +	its_send_mapd(dev, true);
>> +
>> +	collection[0] = its_create_collection(nr_cpus - 1, nr_cpus - 1);
>> +	collection[1] = its_create_collection(nr_cpus - 2, nr_cpus - 2);
>> +	its_send_mapc(collection[0], true);
>> +	its_send_mapc(collection[1], true);
>> +
>> +	/* disable lpi at redist level */
>> +	gicv3_lpi_rdist_ctrl(nr_cpus - 1, false);
>> +	gicv3_lpi_rdist_ctrl(nr_cpus - 2, false);
>> +
>> +	/* even lpis are assigned to even cpu */
>> +	for (i = 0; i < 256; i++) {
>> +		struct its_collection *col = i % 2 ? collection[0] :
>> +						     collection[1];
>> +		int vcpu = col->target_address >> 16;
> 
> I'm lost with the even/odd (nr_cpus - 1)/(nr_cpus - 2) stuff, and won't
> it swap if nr_cpus is odd vs. even?
> 
> Shouldn't we just have something like
> 
>   pe1 = nr_cpus - 1;
>   pe2 = nr_cpus - 2;
>   col1 = its_create_collection(pe1, pe1);
>   col2 = its_create_collection(pe2, pe2);
> 
> without mentioning even and odd?
OK
> 
>> +
>> +		its_send_mapti(dev, 8192 + i, i, col);
>> +		gicv3_lpi_set_config(8192 + i, LPI_PROP_DEFAULT);
>> +		gicv3_lpi_set_pending_table_bit(vcpu, 8192 + i, true);
>> +	}
>> +	its_send_invall(collection[0]);
>> +	its_send_invall(collection[1]);
>> +
>> +	/* Set the PTZ bit on each pendbaser */
>> +
>> +	expected[nr_cpus - 1] = 128;
>> +	expected[nr_cpus - 2] = 128;
>> +
>> +	ptr = gicv3_data.redist_base[nr_cpus - 1] + GICR_PENDBASER;
>> +	pendbaser = readq(ptr);
>> +	writeq(pendbaser & ~GICR_PENDBASER_PTZ, ptr);
>> +
>> +	ptr = gicv3_data.redist_base[nr_cpus - 2] + GICR_PENDBASER;
>> +	pendbaser = readq(ptr);
>> +	writeq(pendbaser & ~GICR_PENDBASER_PTZ, ptr);
>> +
>> +	gicv3_lpi_rdist_ctrl(nr_cpus - 1, true);
>> +	gicv3_lpi_rdist_ctrl(nr_cpus - 2, true);
>> +
>> +	puts("Now migrate the VM, then press a key to continue...\n");
>> +	(void)getchar();
>> +	report(true, "Migration complete");
> 
> report_info
OK
> 
>> +
>> +	mdelay(1000);
> 
> This delay needs a comment explaining why it's here.
OK

Thanks

Eric
> 
>> +
>> +	check_lpi_hits(expected);
>> +}
>>  #endif
>>  
>>  int main(int argc, char **argv)
>> @@ -847,6 +989,14 @@ int main(int argc, char **argv)
>>  		report_prefix_push(argv[1]);
>>  		test_its_migration();
>>  		report_prefix_pop();
>> +	} else if (!strcmp(argv[1], "its-pending-migration")) {
>> +		report_prefix_push(argv[1]);
>> +		test_its_pending_migration();
>> +		report_prefix_pop();
>> +	} else if (!strcmp(argv[1], "its-migrate-unmapped-collection")) {
>> +		report_prefix_push(argv[1]);
>> +		test_migrate_unmapped_collection();
>> +		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 8b8ec79..d917157 100644
>> --- a/arm/unittests.cfg
>> +++ b/arm/unittests.cfg
>> @@ -144,6 +144,22 @@ extra_params = -machine gic-version=3 -append 'its-migration'
>>  groups = its migration
>>  arch = arm64
>>  
>> +[its-pending-migration]
>> +file = gic.flat
>> +smp = $MAX_SMP
>> +accel = kvm
>> +extra_params = -machine gic-version=3 -append 'its-pending-migration'
>> +groups = its migration
>> +arch = arm64
>> +
>> +[its-migrate-unmapped-collection]
>> +file = gic.flat
>> +smp = $MAX_SMP
>> +accel = kvm
>> +extra_params = -machine gic-version=3 -append 'its-migrate-unmapped-collection'
>> +groups = its migration
>> +arch = arm64
>> +
>>  # Test PSCI emulation
>>  [psci]
>>  file = psci.flat
>> -- 
>> 2.20.1
>>
>>
> 
> Thanks,
> drew 
>