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 7DD45397E89; Sat, 30 May 2026 08:54:44 +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=1780131288; cv=none; b=IS7+WTekr10FH1/liuH+/SBnO8dyTJ5JLq8RBc4/keTX4+jxioIb/dV92nBImJgbbdzsx9ybtXEi4ALQ/WFM0wFPVLLZEepbq4Bh07g5o5GMUgRjqKSS4eY9E8uDhuEEq5Fz1FLsKsvW+XfrlqqaJWQqYalcfj9Yhv1fesQ3kFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780131288; c=relaxed/simple; bh=4cZov+A3y+NozKLYxMCn9IIRmUK0h0TSROhccA5wsa0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=j/ZisUFNXoiqrCL8b246cxL1wM9uMKdRP+iWmmrRaSxbzB5G8mGBVfZodFKjoTOPGVHhkJcjzEOV3ZxtM/hOQ4N18TKhGzFZh/CjYBnV0E4sO2QiU/6RelmViwP7YKOyOF/EczKQ7d/a1d33dw/es6GT4WrMlGSbQFHIXzx2tI4= 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=J7vXrRCj; 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="J7vXrRCj" 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 A27CF3515; Sat, 30 May 2026 01:54:38 -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 443803F632; Sat, 30 May 2026 01:54:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780131283; bh=4cZov+A3y+NozKLYxMCn9IIRmUK0h0TSROhccA5wsa0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J7vXrRCjeTz2K4K0t8Fb3OQAuJPDHX31KDGsmxXofYv0yvYJf/qvZ2wnpRROnnaYP e04nFWjsRPDSwCg1cDKvzlSgwdatl7o2A8PHdvJc0b/SICzm4S0K6Wp56KYICONENR zMn57gcJqiGle9dAxIDEtfCYkzdGByEtp95V17l0= 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, usama.arif@linux.dev, ryan.roberts@arm.com, anshuman.khandual@arm.com Subject: [PATCH v2 2/2] selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries Date: Sat, 30 May 2026 08:54:12 +0000 Message-ID: <20260530085413.1270139-3-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260530085413.1270139-1-dev.jain@arm.com> References: <20260530085413.1270139-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-fsdevel@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 | 29 ++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index e1c8a679a4cf3..d09d4a9081de1 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; @@ -2318,6 +2321,32 @@ 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_EQ(entry & PM_PRESENT, 0); + } + + 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