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From: Ralph Campbell <rcampbell@nvidia.com>
To: <nouveau@lists.freedesktop.org>, <linux-rdma@vger.kernel.org>,
	<linux-mm@kvack.org>, <linux-kselftest@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Cc: Jerome Glisse <jglisse@redhat.com>,
	John Hubbard <jhubbard@nvidia.com>,
	Christoph Hellwig <hch@lst.de>,
	Jason Gunthorpe <jgg@mellanox.com>,
	"Ben Skeggs" <bskeggs@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Shuah Khan" <shuah@linuxfoundation.org>,
	Ralph Campbell <rcampbell@nvidia.com>
Subject: [PATCH 6/6] hmm: add tests for HMM_PFN_COMPOUND flag
Date: Fri, 8 May 2020 12:20:09 -0700	[thread overview]
Message-ID: <20200508192009.15302-7-rcampbell@nvidia.com> (raw)
In-Reply-To: <20200508192009.15302-1-rcampbell@nvidia.com>

Add some sanity tests for hmm_range_fault() returning the HMM_PFN_COMPOUND
flag.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
---
 lib/test_hmm.c                         |  2 +
 lib/test_hmm_uapi.h                    |  2 +
 tools/testing/selftests/vm/hmm-tests.c | 76 ++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)

diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 00bca6116f93..8448921e6d33 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -757,6 +757,8 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range,
 		*perm |= HMM_DMIRROR_PROT_WRITE;
 	else
 		*perm |= HMM_DMIRROR_PROT_READ;
+	if (entry & HMM_PFN_COMPOUND)
+		*perm |= HMM_DMIRROR_PROT_COMPOUND;
 }
 
 static bool dmirror_snapshot_invalidate(struct mmu_interval_notifier *mni,
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
index 67b3b2e6ff5d..21cf4da6f020 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -40,6 +40,7 @@ struct hmm_dmirror_cmd {
  * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
  * HMM_DMIRROR_PROT_READ: read-only PTE
  * HMM_DMIRROR_PROT_WRITE: read/write PTE
+ * HMM_DMIRROR_PROT_COMPOUND: compound page is fully mapped by same permissions
  * HMM_DMIRROR_PROT_ZERO: special read-only zero page
  * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
  *					device the ioctl() is made
@@ -51,6 +52,7 @@ enum {
 	HMM_DMIRROR_PROT_NONE			= 0x00,
 	HMM_DMIRROR_PROT_READ			= 0x01,
 	HMM_DMIRROR_PROT_WRITE			= 0x02,
+	HMM_DMIRROR_PROT_COMPOUND		= 0x04,
 	HMM_DMIRROR_PROT_ZERO			= 0x10,
 	HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL	= 0x20,
 	HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE	= 0x30,
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 79db22604019..e9576d9802c7 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -1291,6 +1291,82 @@ TEST_F(hmm2, snapshot)
 	hmm_buffer_free(buffer);
 }
 
+/*
+ * Test the hmm_range_fault() HMM_PFN_COMPOUND flag for large pages that
+ * should be mapped by a large page table entry.
+ */
+TEST_F(hmm, compound)
+{
+	struct hmm_buffer *buffer;
+	unsigned long npages;
+	unsigned long size;
+	int *ptr;
+	unsigned char *m;
+	int ret;
+	long pagesizes[4];
+	int n, idx;
+	unsigned long i;
+
+	/* Skip test if we can't allocate a hugetlbfs page. */
+
+	n = gethugepagesizes(pagesizes, 4);
+	if (n <= 0)
+		return;
+	for (idx = 0; --n > 0; ) {
+		if (pagesizes[n] < pagesizes[idx])
+			idx = n;
+	}
+	size = ALIGN(TWOMEG, pagesizes[idx]);
+	npages = size >> self->page_shift;
+
+	buffer = malloc(sizeof(*buffer));
+	ASSERT_NE(buffer, NULL);
+
+	buffer->ptr = get_hugepage_region(size, GHR_STRICT);
+	if (buffer->ptr == NULL) {
+		free(buffer);
+		return;
+	}
+
+	buffer->size = size;
+	buffer->mirror = malloc(npages);
+	ASSERT_NE(buffer->mirror, NULL);
+
+	/* Initialize the pages the device will snapshot in buffer->ptr. */
+	for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+		ptr[i] = i;
+
+	/* Simulate a device snapshotting CPU pagetables. */
+	ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
+	ASSERT_EQ(ret, 0);
+	ASSERT_EQ(buffer->cpages, npages);
+
+	/* Check what the device saw. */
+	m = buffer->mirror;
+	for (i = 0; i < npages; ++i)
+		ASSERT_EQ(m[i], HMM_DMIRROR_PROT_WRITE |
+				HMM_DMIRROR_PROT_COMPOUND);
+
+	/* Make the region read-only. */
+	ret = mprotect(buffer->ptr, size, PROT_READ);
+	ASSERT_EQ(ret, 0);
+
+	/* Simulate a device snapshotting CPU pagetables. */
+	ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
+	ASSERT_EQ(ret, 0);
+	ASSERT_EQ(buffer->cpages, npages);
+
+	/* Check what the device saw. */
+	m = buffer->mirror;
+	for (i = 0; i < npages; ++i)
+		ASSERT_EQ(m[i], HMM_DMIRROR_PROT_READ |
+				HMM_DMIRROR_PROT_COMPOUND);
+
+	free_hugepage_region(buffer->ptr);
+	buffer->ptr = NULL;
+	hmm_buffer_free(buffer);
+}
+
 /*
  * Test two devices reading the same memory (double mapped).
  */
-- 
2.20.1



  parent reply	other threads:[~2020-05-08 19:20 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-08 19:20 [PATCH 0/6] nouveau/hmm: add support for mapping large pages Ralph Campbell
2020-05-08 19:20 ` [PATCH 1/6] nouveau/hmm: map pages after migration Ralph Campbell
2020-05-08 19:20 ` [PATCH 2/6] nouveau: make nvkm_vmm_ctor() and nvkm_mmu_ptp_get() static Ralph Campbell
2020-05-08 19:20 ` [PATCH 3/6] nouveau/hmm: fault one page at a time Ralph Campbell
2020-05-08 19:20 ` [PATCH 4/6] mm/hmm: add output flag for compound page mapping Ralph Campbell
2020-05-08 19:51   ` Christoph Hellwig
2020-05-08 20:06     ` Ralph Campbell
2020-05-26 22:29       ` Zi Yan
2020-05-26 22:47         ` Ralph Campbell
2020-05-08 19:20 ` [PATCH 5/6] nouveau/hmm: support mapping large sysmem pages Ralph Campbell
2020-05-08 19:20 ` Ralph Campbell [this message]
2020-05-08 19:59 ` [PATCH 0/6] nouveau/hmm: add support for mapping large pages Matthew Wilcox
2020-05-08 20:17   ` Ralph Campbell
2020-05-09  3:17     ` Matthew Wilcox
2020-05-11 17:07       ` Ralph Campbell
2020-05-25 13:41 ` Jason Gunthorpe
2020-05-26 17:32   ` Ralph Campbell
2020-05-29 23:24     ` Jason Gunthorpe

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