From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3F103372EFF; Thu, 4 Jun 2026 05:53:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552420; cv=none; b=mLCzlOjsTFrDWoVA2X7cICAn91OJGCg8NYZZvvKqWrYWthGLJvPFFpx0bWumvFc6c4aLUo9DgPWUSQkktFTqdWDuS32XOsNuenOHTVrsr4b+1QQ8sVRSWJS9UrcQKwr1503RR/uUfQ0UOTMAitnlUjG+UvHwOkBrb0KiScwY6hg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552420; c=relaxed/simple; bh=4rGQj+ttPYrbAPiFOCuG9APk6p34IFP1qYSW6A86tnM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ovIjLrLtVwa5l3NjshuLiA59bceALgdq5QqahEE91mWTGKzUyIMmS0SS7WsmbjN99QOXTm8atxAqW5V02Q8CBQCTfKkMq9WsotJAxn20wE7LwcUgPWtda4k8pitA4IECd10h6ASX6lXcywDENpGtyWM7f6oznN5uOxexECPq2mI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=m8xTLEBX; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="m8xTLEBX" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A7BD1302F; Wed, 3 Jun 2026 22:53:33 -0700 (PDT) Received: from cesw-amp-gbt-1s-m12830-01.blr.arm.com (cesw-amp-gbt-1s-m12830-01.blr.arm.com [10.164.195.31]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1FA273F632; Wed, 3 Jun 2026 22:53:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780552418; bh=4rGQj+ttPYrbAPiFOCuG9APk6p34IFP1qYSW6A86tnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m8xTLEBXa3wzGDuPDeF6Vj8jVWgoOeLm71olZ/hYv2RKOQF8UTzE2+9HroqAVpxCQ y6XTey5VXwD85ArnHU+jKrOAYxECB1XedJLrOhNjCVxOTmqEi2RiXl/uBdoIUg/4GS JQLc5dxE2LZVeA1B+E0awCz+y4P4OtFVX5WCvfN4= From: Dev Jain To: akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, jgg@ziepe.ca, leon@kernel.org, david@kernel.org, shuah@kernel.org Cc: Dev Jain , vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, balbirs@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kselftest@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, usama.arif@linux.dev Subject: [PATCH v3 2/2] selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries Date: Thu, 4 Jun 2026 05:53:06 +0000 Message-ID: <20260604055308.1947679-3-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260604055308.1947679-1-dev.jain@arm.com> References: <20260604055308.1947679-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To cover pagemap paths scanning PMD entries, add assertions to check whether a device-private PMD entry has the correct pagemap information - the PM_SWAP bit must be on in the pagemap entry. Before that, we must assert through HMM_DMIRROR_SNAPSHOT snapshot that the leaf entry is at PMD level and not PTE level. Signed-off-by: Dev Jain --- tools/testing/selftests/mm/hmm-tests.c | 34 ++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index e1c8a679a4cf3..46e0c8c921c3d 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -2276,8 +2276,11 @@ TEST_F(hmm, migrate_anon_huge_fault) unsigned long npages; unsigned long size; unsigned long i; + unsigned char *m; + uint64_t entry; void *old_ptr; void *map; + int pagemap_fd; int *ptr; int ret; @@ -2300,8 +2303,6 @@ TEST_F(hmm, migrate_anon_huge_fault) npages = size >> self->page_shift; map = (void *)ALIGN((uintptr_t)buffer->ptr, size); - ret = madvise(map, size, MADV_HUGEPAGE); - ASSERT_EQ(ret, 0); old_ptr = buffer->ptr; buffer->ptr = map; @@ -2309,6 +2310,9 @@ TEST_F(hmm, migrate_anon_huge_fault) for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) ptr[i] = i; + ret = madvise(map, size, MADV_COLLAPSE); + ASSERT_EQ(ret, 0); + /* Migrate memory to device. */ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages); ASSERT_EQ(ret, 0); @@ -2318,6 +2322,32 @@ TEST_F(hmm, migrate_anon_huge_fault) for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); + if (!hmm_is_coherent_type(variant->device_number)) { + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, + buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + m = buffer->mirror; + for (i = 0; i < npages; ++i) + ASSERT_EQ(m[i], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL | + HMM_DMIRROR_PROT_WRITE | + HMM_DMIRROR_PROT_PMD); + + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + ASSERT_GE(pagemap_fd, 0); + + for (i = 0; i < npages; ++i) { + entry = pagemap_get_entry(pagemap_fd, + (char *)buffer->ptr + i * self->page_size); + + ASSERT_NE(entry & PM_SWAP, 0); + ASSERT_FALSE(PAGEMAP_PRESENT(entry)); + } + + close(pagemap_fd); + } + /* Fault pages back to system memory and check them. */ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); -- 2.43.0