Re: [kvm-unit-tests PATCH v5 13/13] arm/arm64: ITS: pending table migration test

[Zenghui Yu <yuzenghui@huawei.com>]

Hi Eric,

On 2020/3/10 22:54, 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>
> 
> ---
> 
> v4 -> v5:
> - move stub from header to arm/gic.c
> 
> v3 -> v4:
> - do not talk about odd/even CPUs, use pe0 and pe1
> - comment the delay
> 
> v2 -> v3:
> - tests belong to both its and migration groups
> - use LPI(i)
> - gicv3_lpi_set_pending_table_bit renamed into gicv3_lpi_set_clr_pending
> ---
>   arm/gic.c         | 146 ++++++++++++++++++++++++++++++++++++++++++++++
>   arm/unittests.cfg |  16 +++++
>   2 files changed, 162 insertions(+)
> 
> diff --git a/arm/gic.c b/arm/gic.c
> index b8fbc13..e6ffbc3 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -193,6 +193,7 @@ 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 */
>   }
>   
> @@ -236,6 +237,22 @@ static void secondary_lpi_test(void)
>   	while (1)
>   		wfi();
>   }
> +
> +static void check_lpi_hits(int *expected, const char *msg)
> +{
> +	bool pass = true;
> +	int i;
> +
> +	for (i = 0; i < nr_cpus; i++) {
> +		if (acked[i] != expected[i]) {
> +			report_info("expected %d LPIs on PE #%d, %d observed",
> +				    expected[i], i, acked[i]);
> +			pass = false;
> +			break;
> +		}
> +	}
> +	report(pass, "%s", msg);
> +}
>   #endif
>   
>   static void gicv2_ipi_send_self(void)
> @@ -591,6 +608,8 @@ 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_its_pending_migration(void) {}
> +static void test_migrate_unmapped_collection(void) {}
>   
>   #else /* __aarch64__ */
>   
> @@ -659,6 +678,17 @@ static int its_prerequisites(int nb_cpus)
>   	return 0;
>   }
>   
> +static void set_lpi(struct its_device *dev, u32 eventid, u32 physid,
> +		    struct its_collection *col)
> +{
> +	assert(dev && col);
> +
> +	its_send_mapti(dev, physid, eventid, col);
> +
> +	gicv3_lpi_set_config(physid, LPI_PROP_DEFAULT);
> +	its_send_invall(col);

Again, the col hasn't been mapped currently.

> +}
> +
>   /*
>    * Setup the configuration for those mappings:
>    * dev_id=2 event=20 -> vcpu 3, intid=8195
> @@ -799,6 +829,114 @@ static void test_its_migration(void)
>   	its_send_int(dev7, 255);
>   	check_lpi_stats("dev7/eventid=255 triggers LPI 8196 on PE #2 after migration");
>   }
> +
> +static void test_migrate_unmapped_collection(void)
> +{
> +	struct its_collection *col;
> +	struct its_device *dev2, *dev7;
> +	int pe0 = nr_cpus - 1;
> +	u8 config;
> +
> +	if (its_setup1())
> +		return;
> +
> +	col = its_create_collection(pe0, pe0);
> +	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_info("Migration complete");
> +
> +	/* on the destination, map the collection */
> +	its_send_mapc(col, true);
> +
> +	lpi_stats_expect(2, 8196);
> +	its_send_int(dev7, 255);
> +	check_lpi_stats("dev7/eventid= 255 triggered LPI 8196 on PE #2");
> +
> +	config = gicv3_lpi_get_config(8192);
> +	report(config == LPI_PROP_DEFAULT,
> +	       "Config of LPI 8192 was properly migrated");
> +
> +	lpi_stats_expect(pe0, 8192);
> +	its_send_int(dev2, 0);
> +	check_lpi_stats("dev2/eventid = 0 triggered LPI 8192 on PE0");
> +
> +	/* unmap the collection */
> +	its_send_mapc(col, false);

Again, behavior is unpredictable.

> +
> +	lpi_stats_expect(-1, -1);
> +	its_send_int(dev2, 0);
> +	check_lpi_stats("no LPI triggered after collection unmapping");
> +}
> +
> +static void test_its_pending_migration(void)
> +{
> +	struct its_device *dev;
> +	struct its_collection *collection[2];
> +	int *expected = malloc(nr_cpus * sizeof(int));
> +	int pe0 = nr_cpus - 1, pe1 = nr_cpus - 2;
> +	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(pe0, pe0);
> +	collection[1] = its_create_collection(pe1, pe1);
> +	its_send_mapc(collection[0], true);
> +	its_send_mapc(collection[1], true);
> +
> +	/* disable lpi at redist level */
> +	gicv3_lpi_rdist_disable(pe0);
> +	gicv3_lpi_rdist_disable(pe1);
> +
> +	/* lpis are interleaved inbetween the 2 PEs */
> +	for (i = 0; i < 256; i++) {
> +		struct its_collection *col = i % 2 ? collection[0] :
> +						     collection[1];
> +		int vcpu = col->target_address >> 16;
> +
> +		its_send_mapti(dev, LPI(i), i, col);
> +		gicv3_lpi_set_config(LPI(i), LPI_PROP_DEFAULT);
> +		gicv3_lpi_set_clr_pending(vcpu, LPI(i), true);
> +	}
> +	its_send_invall(collection[0]);
> +	its_send_invall(collection[1]);
> +
> +	/* Set the PTZ bit on each pendbaser */

'Clear' the PTZ.

Otherwise looks good!

> +
> +	expected[pe0] = 128;
> +	expected[pe1] = 128;
> +
> +	ptr = gicv3_data.redist_base[pe0] + GICR_PENDBASER;
> +	pendbaser = readq(ptr);
> +	writeq(pendbaser & ~GICR_PENDBASER_PTZ, ptr);
> +
> +	ptr = gicv3_data.redist_base[pe1] + GICR_PENDBASER;
> +	pendbaser = readq(ptr);
> +	writeq(pendbaser & ~GICR_PENDBASER_PTZ, ptr);
> +
> +	gicv3_lpi_rdist_enable(pe0);
> +	gicv3_lpi_rdist_enable(pe1);
> +
> +	puts("Now migrate the VM, then press a key to continue...\n");
> +	(void)getchar();
> +	report_info("Migration complete");
> +
> +	/* let's wait for the 256 LPIs to be handled */
> +	mdelay(1000);
> +
> +	check_lpi_hits(expected, "128 LPIs on both PE0 and PE1 after migration");
> +}

Thanks,
Zenghui