From nobody Thu Apr 2 05:49:34 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1EC6D3CA4BD for ; Mon, 30 Mar 2026 11:57:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774871824; cv=none; b=nj6yS7T7XG4P/eyAWmZNNS0xHEUpLsvPxvANehBmT0Mjq5lNrODIT5gGizzh4xVoLQW55Uz7+pgIKTqSJjv9cpli+8THB1OQXuC13WG66W69PE1TJTpTqH52+v4kIhsAr0nxs2TotFSOqGxedebBKMsQh6o5seLdDMSP62BaqMg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774871824; c=relaxed/simple; bh=/ZcVUHWjt0HLPeNT9dH2CPu5sMZ/Ui+l/KWWse+jnBA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jTujeOte4Lgkj+xo40JxiwZv8zwJchMCGaklZGpMehBp3/0hSIkwjK6inj4VhZ7+COLxsHnYwJMfCimSxRB5AWmpgmYKWqAIg14w1kTsld1XhpkKgMPi0TZ8uZ0nMB606M0pDYxyXrpyL7mKmWRzWNQWtIOfiniDwlvLaEpkbPs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=EyH4t2vp; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=s+1iBwLO; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EyH4t2vp"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="s+1iBwLO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774871822; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ixwVgPxIz/n/uYpN1Wu+O4jklsKJ4ob7dTgnI6cFXT0=; b=EyH4t2vpGzSle5wXcpPZj1uwWjx+kV2aEALm71ORuemlOuHtGsAGKJOJEadHPeeAYKNaHk dIEuRxwWSsm0YDW5lMfvLSI/D8uUZUFy1YzTM2ZKMXMWoMM0Kt5ORviFYL7RVSBBjlth8S 7n6d771dzeFNi3C6OxtndN8EyNyRuYA= Received: from mail-lj1-f198.google.com (mail-lj1-f198.google.com [209.85.208.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-391-NacUAlVfN_qAmV-8Xq26Iw-1; Mon, 30 Mar 2026 07:56:58 -0400 X-MC-Unique: NacUAlVfN_qAmV-8Xq26Iw-1 X-Mimecast-MFC-AGG-ID: NacUAlVfN_qAmV-8Xq26Iw_1774871817 Received: by mail-lj1-f198.google.com with SMTP id 38308e7fff4ca-38a2794fbc5so17855861fa.0 for ; Mon, 30 Mar 2026 04:56:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1774871817; x=1775476617; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ixwVgPxIz/n/uYpN1Wu+O4jklsKJ4ob7dTgnI6cFXT0=; b=s+1iBwLOS/fpRg1hatGkBkkN3A8O18zN+YnAaPDPCWtyQC35YBN0ZpEXQ7UKGtk38e CJCp3wmwyl3is9Pj5fPHQ4eV/aQ54rf50NRVC7GaJQgp6+qMNuUkqqWidznPFJ6N0yxC ISeImU/c2b6u9/I46tfPJ6isLtauwsz5sjNdBA7/zlqk+vv1YzC1xlkd264Py5IsPPMs Z8Rj0TRLI9FLawYIZF3lUiI+03JJCMxDYci8zBTNjohjUb/KLc8talFgT7uOOF3qz5HX 0esWhA1uxCADvg5AjFSMxrQ3ZLahsQUpKD8DgXOv076n0Y0KCYwil+n3CECox1gBUovw ntMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774871817; x=1775476617; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=ixwVgPxIz/n/uYpN1Wu+O4jklsKJ4ob7dTgnI6cFXT0=; b=MCJ8LhzF59iCMAE8ljYhWr18j3+HpXgKk2ipmmsvrvU4OQ0+t1G2fmrrMX5ERoCm4y +FFZ8UeJ4WsJ+OsbFd3PZ36W4/lh1MA6L/y8xwHqbsvYxOZC539tx7VduMaVG1ZUSW5X e0CJzw+RMktlIK57wGbccO61IJXnzqm9CIqv7h46Ky0rOt1egDFfG/EOUynXj0fTgY/g 4zItlUZ9vq/U+0i18KmOSpgRuu4X1LbdTdsQbFIlvCJnveOzz3/CUb5v6ALGuc2rAmiJ xI902LSOhyi+0HxPVHPu/yxM9SstzAPTnEPJaY2ol8IZPbaj95yN4FIJ12NzHSSb7FuA cWaw== X-Gm-Message-State: AOJu0YyhwKdivcg5oZay3u85inTeEBtwNTLmVNmyaUb0YEMU9Pk4W9Iu K+y35qgCgudDHFdfpX6y/7NvHI554PcpLxSzgsAmbFBFa12b2klwmPjIV2DOCxsIG39tRO42XwI d3jc1dVL5h+VqpkE8oPoc1o5WJ/UUZPT53yfNJM6wEQrvoWlDtLUa/jEHQoVaK+Su X-Gm-Gg: ATEYQzxew09MDummo5jPQIJHOzRCBZJdFI5LBxgm4ADubJe9JRFAkLskYYiHsG0dBd3 rua1sqnSAlFK9kKS8aOBEC7B/mxiBHGFfHLG0e5R64sGIld/EPLuVenipkfRk5IBNqpE08dGXij /xTz8Nj1SVlDeOyS4AQSeSWDtvZ2+QHrdMmj6X0eE+Nw41Cp94w2gBfxb9nUQLBVo0GDUrZbGho LlpszvUH4kHXaeAgLT4HiQgcAcX1fNcrPMf3077MwF1Ve5qQQrOpDYjSd60DhQdBkaH1GXJaN43 o25FRRVq4G0pHBVv4JKC09qO6vySbziS7Rn5HZSHuWm4oFY6poIkzOKVr25IQOuIb91l7BFA5qt 0J7q+857fjNVN646ZrTsuudMVWqofCdBbwGXF X-Received: by 2002:a05:651c:4107:b0:38a:8b97:7ec1 with SMTP id 38308e7fff4ca-38c7405ab98mr23353281fa.23.1774871817064; Mon, 30 Mar 2026 04:56:57 -0700 (PDT) X-Received: by 2002:a05:651c:4107:b0:38a:8b97:7ec1 with SMTP id 38308e7fff4ca-38c7405ab98mr23353101fa.23.1774871816441; Mon, 30 Mar 2026 04:56:56 -0700 (PDT) Received: from fedora (85-23-51-1.bb.dnainternet.fi. [85.23.51.1]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-38c838daa4bsm16330071fa.32.2026.03.30.04.56.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Mar 2026 04:56:55 -0700 (PDT) From: mpenttil@redhat.com To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Mika=20Penttil=C3=A4?= , David Hildenbrand , Jason Gunthorpe , Leon Romanovsky , Alistair Popple , Balbir Singh , Zi Yan , Matthew Brost , Marco Pagani Subject: [PATCH v7 5/6] mm: add new testcase for the migrate on fault case Date: Mon, 30 Mar 2026 14:56:10 +0300 Message-ID: <20260330115611.347988-6-mpenttil@redhat.com> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20260330115611.347988-1-mpenttil@redhat.com> References: <20260330115611.347988-1-mpenttil@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Mika Penttil=C3=A4 Cc: David Hildenbrand Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Alistair Popple Cc: Balbir Singh Cc: Zi Yan Cc: Matthew Brost Signed-off-by: Marco Pagani Signed-off-by: Mika Penttil=C3=A4 --- lib/test_hmm.c | 99 ++++++++++++++++++++++++++ lib/test_hmm_uapi.h | 19 ++--- tools/testing/selftests/mm/hmm-tests.c | 54 ++++++++++++++ 3 files changed, 163 insertions(+), 9 deletions(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 01aa0b60df2f..5ddcec056dfb 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -36,6 +36,7 @@ #define DMIRROR_RANGE_FAULT_TIMEOUT 1000 #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) #define DEVMEM_CHUNKS_RESERVE 16 +#define PFNS_ARRAY_SIZE 64 =20 /* * For device_private pages, dpage is just a dummy struct page @@ -1196,6 +1197,100 @@ static int dmirror_migrate_to_device(struct dmirror= *dmirror, return ret; } =20 +static int do_fault_and_migrate(struct dmirror *dmirror, struct hmm_range = *range) +{ + struct migrate_vma *migrate =3D range->migrate; + int ret; + + mmap_read_lock(dmirror->notifier.mm); + + /* Fault-in pages for migration and update device page table */ + ret =3D dmirror_range_fault(dmirror, range); + + pr_debug("Migrating from sys mem to device mem\n"); + migrate_hmm_range_setup(range); + + dmirror_migrate_alloc_and_copy(migrate, dmirror); + migrate_vma_pages(migrate); + dmirror_migrate_finalize_and_map(migrate, dmirror); + migrate_vma_finalize(migrate); + + mmap_read_unlock(dmirror->notifier.mm); + return ret; +} + +static int dmirror_fault_and_migrate_to_device(struct dmirror *dmirror, + struct hmm_dmirror_cmd *cmd) +{ + unsigned long start, size, end, next; + unsigned long src_pfns[PFNS_ARRAY_SIZE] =3D { 0 }; + unsigned long dst_pfns[PFNS_ARRAY_SIZE] =3D { 0 }; + struct migrate_vma migrate =3D { 0 }; + struct hmm_range range =3D { 0 }; + struct dmirror_bounce bounce; + int ret =3D 0; + + /* Whole range */ + start =3D cmd->addr; + size =3D cmd->npages << PAGE_SHIFT; + end =3D start + size; + + if (!mmget_not_zero(dmirror->notifier.mm)) { + ret =3D -EFAULT; + goto out; + } + + migrate.pgmap_owner =3D dmirror->mdevice; + migrate.src =3D src_pfns; + migrate.dst =3D dst_pfns; + migrate.flags =3D MIGRATE_VMA_SELECT_SYSTEM; + + range.migrate =3D &migrate; + range.hmm_pfns =3D src_pfns; + range.pfn_flags_mask =3D 0; + range.default_flags =3D HMM_PFN_REQ_FAULT | HMM_PFN_REQ_MIGRATE; + range.dev_private_owner =3D dmirror->mdevice; + range.notifier =3D &dmirror->notifier; + + for (next =3D start; next < end; next =3D range.end) { + range.start =3D next; + range.end =3D min(end, next + (PFNS_ARRAY_SIZE << PAGE_SHIFT)); + + pr_debug("Fault and migrate range start:%#lx end:%#lx\n", + range.start, range.end); + + ret =3D do_fault_and_migrate(dmirror, &range); + if (ret) + goto out_mmput; + } + + /* + * Return the migrated data for verification. + * Only for pages in device zone + */ + ret =3D dmirror_bounce_init(&bounce, start, size); + if (ret) + goto out_mmput; + + mutex_lock(&dmirror->mutex); + ret =3D dmirror_do_read(dmirror, start, end, &bounce); + mutex_unlock(&dmirror->mutex); + if (ret =3D=3D 0) { + ret =3D copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, bounce.size); + if (ret) + ret =3D -EFAULT; + } + + cmd->cpages =3D bounce.cpages; + dmirror_bounce_fini(&bounce); + + +out_mmput: + mmput(dmirror->notifier.mm); +out: + return ret; +} + static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *ran= ge, unsigned char *perm, unsigned long entry) { @@ -1512,6 +1607,10 @@ static long dmirror_fops_unlocked_ioctl(struct file = *filp, ret =3D dmirror_migrate_to_device(dmirror, &cmd); break; =20 + case HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV: + ret =3D dmirror_fault_and_migrate_to_device(dmirror, &cmd); + break; + case HMM_DMIRROR_MIGRATE_TO_SYS: ret =3D dmirror_migrate_to_system(dmirror, &cmd); break; diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index f94c6d457338..0b6e7a419e36 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -29,15 +29,16 @@ struct hmm_dmirror_cmd { }; =20 /* Expose the address space of the calling process through hmm device file= */ -#define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cm= d) -#define HMM_DMIRROR_RELEASE _IOWR('H', 0x07, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_FLAGS _IOWR('H', 0x08, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cm= d) +#define HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV _IOWR('H', 0x03, struct hmm_dm= irror_cmd) +#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x04, struct hmm_dmirror_cm= d) +#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x05, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x07, struct hmm_dmirror_c= md) +#define HMM_DMIRROR_RELEASE _IOWR('H', 0x08, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_FLAGS _IOWR('H', 0x09, struct hmm_dmirror_cmd) =20 #define HMM_DMIRROR_FLAG_FAIL_ALLOC (1ULL << 0) =20 diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftes= ts/mm/hmm-tests.c index e8328c89d855..c75616875c9e 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -277,6 +277,13 @@ static int hmm_migrate_sys_to_dev(int fd, return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_DEV, buffer, npages); } =20 +static int hmm_migrate_on_fault_sys_to_dev(int fd, + struct hmm_buffer *buffer, + unsigned long npages) +{ + return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV, buffer, n= pages); +} + static int hmm_migrate_dev_to_sys(int fd, struct hmm_buffer *buffer, unsigned long npages) @@ -1034,6 +1041,53 @@ TEST_F(hmm, migrate) hmm_buffer_free(buffer); } =20 + +/* + * Fault and migrate anonymous memory to device private memory. + */ +TEST_F(hmm, migrate_on_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + + npages =3D ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size =3D npages << self->page_shift; + + buffer =3D malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd =3D -1; + buffer->size =3D size; + buffer->mirror =3D malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + buffer->ptr =3D mmap(NULL, size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + /* Initialize buffer in system memory. */ + for (i =3D 0, ptr =3D buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] =3D i; + + /* Fault and migrate memory to device. */ + ret =3D hmm_migrate_on_fault_sys_to_dev(self->fd, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device read. */ + for (i =3D 0, ptr =3D buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); +} + /* * Migrate anonymous memory to device private memory and fault some of it = back * to system memory, then try migrating the resulting mix of system and de= vice --=20 2.50.0