Re: [PATCH v3 09/10] tools: update hmm-test to support device coherent type

Sierra Guiza, Alejandro (Alex)
2022-01-27T03:22:25Z

On 1/20/2022 12:14 AM, Alistair Popple wrote:
> On Tuesday, 11 January 2022 9:32:00 AM AEDT Alex Sierra wrote:
>> Test cases such as migrate_fault and migrate_multiple, were modified to
>> explicit migrate from device to sys memory without the need of page
>> faults, when using device coherent type.
>>
>> Snapshot test case updated to read memory device type first and based
>> on that, get the proper returned results migrate_ping_pong test case
> Where is the migrate_ping_pong test? Did you perhaps forget to add it? :-)

Migration from device coherent to system is tested with migrate_multiple
too. Therefore,
I've removed migrate_ping_pong test. BTW, I just added the "number of
pages migrated"
checker after migrate from coherent to system on v4 series.

Regards,
Alejandro Sierra

>
>> added to test explicit migration from device to sys memory for both
>> private and coherent zone types.
>>
>> Helpers to migrate from device to sys memory and vicerversa
>> were also added.
>>
>> Signed-off-by: Alex Sierra <alex.sierra@amd.com>
>> ---
>> v2:
>> Set FIXTURE_VARIANT to add multiple device types to the FIXTURE. This
>> will run all the tests for each device type (private and coherent) in
>> case both existed during hmm-test driver probed.
>> ---
>> tools/testing/selftests/vm/hmm-tests.c | 122 ++++++++++++++++++++-----
>> 1 file changed, 101 insertions(+), 21 deletions(-)
>>
>> diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
>> index 864f126ffd78..8eb81dfba4b3 100644
>> --- a/tools/testing/selftests/vm/hmm-tests.c
>> +++ b/tools/testing/selftests/vm/hmm-tests.c
>> @@ -44,6 +44,14 @@ struct hmm_buffer {
>> int fd;
>> uint64_t cpages;
>> uint64_t faults;
>> + int zone_device_type;
>> +};
>> +
>> +enum {
>> + HMM_PRIVATE_DEVICE_ONE,
>> + HMM_PRIVATE_DEVICE_TWO,
>> + HMM_COHERENCE_DEVICE_ONE,
>> + HMM_COHERENCE_DEVICE_TWO,
>> };
>>
>> #define TWOMEG (1 << 21)
>> @@ -60,6 +68,21 @@ FIXTURE(hmm)
>> unsigned int page_shift;
>> };
>>
>> +FIXTURE_VARIANT(hmm)
>> +{
>> + int device_number;
>> +};
>> +
>> +FIXTURE_VARIANT_ADD(hmm, hmm_device_private)
>> +{
>> + .device_number = HMM_PRIVATE_DEVICE_ONE,
>> +};
>> +
>> +FIXTURE_VARIANT_ADD(hmm, hmm_device_coherent)
>> +{
>> + .device_number = HMM_COHERENCE_DEVICE_ONE,
>> +};
>> +
>> FIXTURE(hmm2)
>> {
>> int fd0;
>> @@ -68,6 +91,24 @@ FIXTURE(hmm2)
>> unsigned int page_shift;
>> };
>>
>> +FIXTURE_VARIANT(hmm2)
>> +{
>> + int device_number0;
>> + int device_number1;
>> +};
>> +
>> +FIXTURE_VARIANT_ADD(hmm2, hmm2_device_private)
>> +{
>> + .device_number0 = HMM_PRIVATE_DEVICE_ONE,
>> + .device_number1 = HMM_PRIVATE_DEVICE_TWO,
>> +};
>> +
>> +FIXTURE_VARIANT_ADD(hmm2, hmm2_device_coherent)
>> +{
>> + .device_number0 = HMM_COHERENCE_DEVICE_ONE,
>> + .device_number1 = HMM_COHERENCE_DEVICE_TWO,
>> +};
>> +
>> static int hmm_open(int unit)
>> {
>> char pathname[HMM_PATH_MAX];
>> @@ -81,12 +122,19 @@ static int hmm_open(int unit)
>> return fd;
>> }
>>
>> +static bool hmm_is_coherent_type(int dev_num)
>> +{
>> + return (dev_num >= HMM_COHERENCE_DEVICE_ONE);
>> +}
>> +
>> FIXTURE_SETUP(hmm)
>> {
>> self->page_size = sysconf(_SC_PAGE_SIZE);
>> self->page_shift = ffs(self->page_size) - 1;
>>
>> - self->fd = hmm_open(0);
>> + self->fd = hmm_open(variant->device_number);
>> + if (self->fd < 0 && hmm_is_coherent_type(variant->device_number))
>> + SKIP(exit(0), "DEVICE_COHERENT not available");
>> ASSERT_GE(self->fd, 0);
>> }
>>
>> @@ -95,9 +143,11 @@ FIXTURE_SETUP(hmm2)
>> self->page_size = sysconf(_SC_PAGE_SIZE);
>> self->page_shift = ffs(self->page_size) - 1;
>>
>> - self->fd0 = hmm_open(0);
>> + self->fd0 = hmm_open(variant->device_number0);
>> + if (self->fd0 < 0 && hmm_is_coherent_type(variant->device_number0))
>> + SKIP(exit(0), "DEVICE_COHERENT not available");
>> ASSERT_GE(self->fd0, 0);
>> - self->fd1 = hmm_open(1);
>> + self->fd1 = hmm_open(variant->device_number1);
>> ASSERT_GE(self->fd1, 0);
>> }
>>
>> @@ -144,6 +194,7 @@ static int hmm_dmirror_cmd(int fd,
>> }
>> buffer->cpages = cmd.cpages;
>> buffer->faults = cmd.faults;
>> + buffer->zone_device_type = cmd.zone_device_type;
>>
>> return 0;
>> }
>> @@ -211,6 +262,20 @@ static void hmm_nanosleep(unsigned int n)
>> nanosleep(&t, NULL);
>> }
>>
>> +static int hmm_migrate_sys_to_dev(int fd,
>> + struct hmm_buffer *buffer,
>> + unsigned long npages)
>> +{
>> + return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_DEV, buffer, npages);
>> +}
>> +
>> +static int hmm_migrate_dev_to_sys(int fd,
>> + struct hmm_buffer *buffer,
>> + unsigned long npages)
>> +{
>> + return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_SYS, buffer, npages);
>> +}
>> +
>> /*
>> * Simple NULL test of device open/close.
>> */
>> @@ -875,7 +940,7 @@ TEST_F(hmm, migrate)
>> ptr[i] = i;
>>
>> /* Migrate memory to device. */
>> - ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, npages);
>>
>> @@ -923,7 +988,7 @@ TEST_F(hmm, migrate_fault)
>> ptr[i] = i;
>>
>> /* Migrate memory to device. */
>> - ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, npages);
>>
>> @@ -936,7 +1001,7 @@ TEST_F(hmm, migrate_fault)
>> ASSERT_EQ(ptr[i], i);
>>
>> /* Migrate memory to the device again. */
>> - ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, npages);
>>
>> @@ -976,7 +1041,7 @@ TEST_F(hmm, migrate_shared)
>> ASSERT_NE(buffer->ptr, MAP_FAILED);
>>
>> /* Migrate memory to device. */
>> - ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
>> ASSERT_EQ(ret, -ENOENT);
>>
>> hmm_buffer_free(buffer);
>> @@ -1015,7 +1080,7 @@ TEST_F(hmm2, migrate_mixed)
>> p = buffer->ptr;
>>
>> /* Migrating a protected area should be an error. */
>> - ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd1, buffer, npages);
>> ASSERT_EQ(ret, -EINVAL);
>>
>> /* Punch a hole after the first page address. */
>> @@ -1023,7 +1088,7 @@ TEST_F(hmm2, migrate_mixed)
>> ASSERT_EQ(ret, 0);
>>
>> /* We expect an error if the vma doesn't cover the range. */
>> - ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 3);
>> + ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 3);
>> ASSERT_EQ(ret, -EINVAL);
>>
>> /* Page 2 will be a read-only zero page. */
>> @@ -1055,13 +1120,13 @@ TEST_F(hmm2, migrate_mixed)
>>
>> /* Now try to migrate pages 2-5 to device 1. */
>> buffer->ptr = p + 2 * self->page_size;
>> - ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 4);
>> + ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 4);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, 4);
>>
>> /* Page 5 won't be migrated to device 0 because it's on device 1. */
>> buffer->ptr = p + 5 * self->page_size;
>> - ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
>> + ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
>> ASSERT_EQ(ret, -ENOENT);
>> buffer->ptr = p;
>>
>> @@ -1070,8 +1135,12 @@ TEST_F(hmm2, migrate_mixed)
>> }
>>
>> /*
>> - * Migrate anonymous memory to device private memory and fault it back to system
>> - * memory multiple times.
>> + * Migrate anonymous memory to device memory and back to system memory
>> + * multiple times. In case of private zone configuration, this is done
>> + * through fault pages accessed by CPU. In case of coherent zone configuration,
>> + * the pages from the device should be explicitly migrated back to system memory.
>> + * The reason is Coherent device zone has coherent access by CPU, therefore
>> + * it will not generate any page fault.
>> */
>> TEST_F(hmm, migrate_multiple)
>> {
>> @@ -1107,8 +1176,7 @@ TEST_F(hmm, migrate_multiple)
>> ptr[i] = i;
>>
>> /* Migrate memory to device. */
>> - ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer,
>> - npages);
>> + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, npages);
>>
>> @@ -1116,7 +1184,12 @@ TEST_F(hmm, migrate_multiple)
>> for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
>> ASSERT_EQ(ptr[i], i);
>>
>> - /* Fault pages back to system memory and check them. */
>> + /* Migrate back to system memory and check them. */
>> + if (hmm_is_coherent_type(variant->device_number)) {
>> + ret = hmm_migrate_dev_to_sys(self->fd, buffer, npages);
> So I think this will still pass even if nothing migrates so as mentioned on
> the previous patch I think we need to check for the number of pages that
> actually migrated. Alternatively I suppose you could do a snapshot and check
> that, but that seems like it would be harder. Otherwise I think this looks
> good.
>
>> + ASSERT_EQ(ret, 0);
>> + }
>> +
>> for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
>> ASSERT_EQ(ptr[i], i);
>>
>> @@ -1312,13 +1385,13 @@ TEST_F(hmm2, snapshot)
>>
>> /* Page 5 will be migrated to device 0. */
>> buffer->ptr = p + 5 * self->page_size;
>> - ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
>> + ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, 1);
>>
>> /* Page 6 will be migrated to device 1. */
>> buffer->ptr = p + 6 * self->page_size;
>> - ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 1);
>> + ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 1);
>> ASSERT_EQ(ret, 0);
>> ASSERT_EQ(buffer->cpages, 1);
>>
>> @@ -1335,9 +1408,16 @@ TEST_F(hmm2, snapshot)
>> ASSERT_EQ(m[2], HMM_DMIRROR_PROT_ZERO | HMM_DMIRROR_PROT_READ);
>> ASSERT_EQ(m[3], HMM_DMIRROR_PROT_READ);
>> ASSERT_EQ(m[4], HMM_DMIRROR_PROT_WRITE);
>> - ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
>> - HMM_DMIRROR_PROT_WRITE);
>> - ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
>> + if (!hmm_is_coherent_type(variant->device_number0)) {
>> + ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
>> + HMM_DMIRROR_PROT_WRITE);
>> + ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
>> + } else {
>> + ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL |
>> + HMM_DMIRROR_PROT_WRITE);
>> + ASSERT_EQ(m[6], HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE |
>> + HMM_DMIRROR_PROT_WRITE);
>> + }
>>
>> hmm_buffer_free(buffer);
>> }
>>
>
>
>