On Thu, Oct 19, 2023 at 10:29:27AM -0700, Axel Rasmussen wrote:
On Thu, Oct 19, 2023 at 8:43 AM Suren Baghdasaryan surenb@google.com wrote:
On Thu, Oct 12, 2023 at 3:29 PM Peter Xu peterx@redhat.com wrote:
On Sun, Oct 08, 2023 at 11:42:28PM -0700, Suren Baghdasaryan wrote:
Add a test for new UFFDIO_MOVE ioctl which uses uffd to move source into destination buffer while checking the contents of both after remapping. After the operation the content of the destination buffer should match the original source buffer's content while the source buffer should be zeroed.
Signed-off-by: Suren Baghdasaryan surenb@google.com
tools/testing/selftests/mm/uffd-common.c | 41 ++++++++++++- tools/testing/selftests/mm/uffd-common.h | 1 + tools/testing/selftests/mm/uffd-unit-tests.c | 62 ++++++++++++++++++++ 3 files changed, 102 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index 02b89860e193..ecc1244f1c2b 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -52,6 +52,13 @@ static int anon_allocate_area(void **alloc_area, bool is_src) *alloc_area = NULL; return -errno; }
/* Prevent source pages from collapsing into THPs */if (madvise(*alloc_area, nr_pages * page_size, MADV_NOHUGEPAGE)) {*alloc_area = NULL;return -errno;}Can we move this to test specific code?
Ack. I think that's doable.
return 0;}
@@ -484,8 +491,14 @@ void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args) offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst; offset &= ~(page_size-1);
if (copy_page(uffd, offset, args->apply_wp))args->missing_faults++;
/* UFFD_MOVE is supported for anon non-shared mappings. */if (uffd_test_ops == &anon_uffd_test_ops && !map_shared) {IIUC this means move_page() will start to run on many other tests... as long as anonymous & private. Probably not wanted, because not all tests may need this MOVE test, and it also means UFFDIO_COPY is never tested on anonymous..
You can overwrite uffd_args.handle_fault(). Axel just added a hook which seems also usable here. See 99aa77215ad02.
Yes, I was thinking about adding a completely new set of tests for UFFDIO_MOVE but was not sure. With your confirmation I'll follow that path so that UFFDIO_COPY tests stay the same.
Sounds good.
If you want you can also torture MOVE a bit with uffd-stress.c to do bouncing test all with MOVE, may need a new option and some more code changes, though.
if (move_page(uffd, offset))args->missing_faults++;} else {if (copy_page(uffd, offset, args->apply_wp))args->missing_faults++;} }}
@@ -620,6 +633,30 @@ int copy_page(int ufd, unsigned long offset, bool wp) return __copy_page(ufd, offset, false, wp); }
+int move_page(int ufd, unsigned long offset) +{
struct uffdio_move uffdio_move;if (offset >= nr_pages * page_size)err("unexpected offset %lu\n", offset);uffdio_move.dst = (unsigned long) area_dst + offset;uffdio_move.src = (unsigned long) area_src + offset;uffdio_move.len = page_size;uffdio_move.mode = UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES;uffdio_move.move = 0;if (ioctl(ufd, UFFDIO_MOVE, &uffdio_move)) {/* real retval in uffdio_move.move */if (uffdio_move.move != -EEXIST)err("UFFDIO_MOVE error: %"PRId64,(int64_t)uffdio_move.move);wake_range(ufd, uffdio_move.dst, page_size);} else if (uffdio_move.move != page_size) {err("UFFDIO_MOVE error: %"PRId64, (int64_t)uffdio_move.move);} elsereturn 1;return 0;+}
int uffd_open_dev(unsigned int flags) { int fd, uffd; diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index 7c4fa964c3b0..f4d79e169a3d 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -111,6 +111,7 @@ void wp_range(int ufd, __u64 start, __u64 len, bool wp); void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args); int __copy_page(int ufd, unsigned long offset, bool retry, bool wp); int copy_page(int ufd, unsigned long offset, bool wp); +int move_page(int ufd, unsigned long offset); void *uffd_poll_thread(void *arg);
int uffd_open_dev(unsigned int flags); diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 2709a34a39c5..f0ded3b34367 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -824,6 +824,10 @@ static void uffd_events_test_common(bool wp) char c; struct uffd_args args = { 0 };
/* Prevent source pages from being mapped more than once */if (madvise(area_src, nr_pages * page_size, MADV_DONTFORK))err("madvise(MADV_DONTFORK) failed");Modifying events test is weird.. I assume you don't need this anymore after you switch to the handle_fault() hook.
I think so but let me try first and I'll get back on that.
fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, true, wp, false))@@ -1062,6 +1066,58 @@ static void uffd_poison_test(uffd_test_args_t *targs) uffd_test_pass(); }
+static void uffd_move_test(uffd_test_args_t *targs) +{
unsigned long nr;pthread_t uffd_mon;char c;unsigned long long count;struct uffd_args args = { 0 };if (uffd_register(uffd, area_dst, nr_pages * page_size,true, false, false))err("register failure");if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args))err("uffd_poll_thread create");/** Read each of the pages back using the UFFD-registered mapping. We* expect that the first time we touch a page, it will result in a missing* fault. uffd_poll_thread will resolve the fault by remapping source* page to destination.*/for (nr = 0; nr < nr_pages; nr++) {/* Check area_src content */count = *area_count(area_src, nr);if (count != count_verify[nr])err("nr %lu source memory invalid %llu %llu\n",nr, count, count_verify[nr]);/* Faulting into area_dst should remap the page */count = *area_count(area_dst, nr);if (count != count_verify[nr])err("nr %lu memory corruption %llu %llu\n",nr, count, count_verify[nr]);/* Re-check area_src content which should be empty */count = *area_count(area_src, nr);if (count != 0)err("nr %lu move failed %llu %llu\n",nr, count, count_verify[nr]);All of above should see zeros, right? Because I don't think anyone boosted the counter at all..
Maybe set some non-zero values to it? Then the re-check can make more sense.
I thought uffd_test_ctx_init() is initializing area_count(area_src, nr), so the source pages should contain non-zero data before the move. Am I missing something?
You're correct, uffd_test_ctx_init() fills in some data in area_src.
Indeed.
If you want, I think we can also make uffd-stress.c test to cover MOVE too, basically replacing all UFFDIO_COPY when e.g. user specified from cmdline. Optional, and may need some touch ups here and there, though.
That's a good idea. I'll add that in the next version. Thanks, Suren.
Thanks,
}if (write(pipefd[1], &c, sizeof(c)) != sizeof(c))err("pipe write");if (pthread_join(uffd_mon, NULL))err("join() failed");if (args.missing_faults != nr_pages || args.minor_faults != 0)uffd_test_fail("stats check error");elseuffd_test_pass();+}
/*
- Test the returned uffdio_register.ioctls with different register modes.
- Note that _UFFDIO_ZEROPAGE is tested separately in the zeropage test.
@@ -1139,6 +1195,12 @@ uffd_test_case_t uffd_tests[] = { .mem_targets = MEM_ALL, .uffd_feature_required = 0, },
{.name = "move",.uffd_fn = uffd_move_test,.mem_targets = MEM_ANON,.uffd_feature_required = UFFD_FEATURE_MOVE,}, { .name = "wp-fork", .uffd_fn = uffd_wp_fork_test,-- 2.42.0.609.gbb76f46606-goog
-- Peter Xu
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