From patchwork Sat Dec 16 06:05:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495486 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 60D2BC4167B for ; Sat, 16 Dec 2023 06:28:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4A17C10E06F; Sat, 16 Dec 2023 06:28:57 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id DCCA210E077 for ; Sat, 16 Dec 2023 06:28:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708136; x=1734244136; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=U5Op4CjhDDAHfKtiDzpe6+9a1b7R8CllBxVTE/TesJE=; b=X4uVLbpDS+02I06SdiYLhOlLbUE4S5z3v/SAYvxeBF7cf9Ybs7g4JVDM 1iC2v5h2ZrIojn+almpaYxVsd0Lbz5M4nYutGmYCG92NNjEXvCGU8lf8A vMMIVcDQWAvIwZDvEb1A/6h8X3PPx/uEDwStWGkprvHUcBVtQckGHMdjy 27MZRecMYN8EaNNb9ZcHtrmgz6HPJzEj9x5dXZRtGNTApVz7dEQMmP8B8 eMOwtcV/KsA0Ug6Io8MAisxRptrDuSGBXauBKvEDPRFAf3aszcnl7GBf2 bkz6FaGgjDeoH7Ds1Hycj8XDsPx81OwBY8NRxve9hYfysgUiI+0p01yTS A==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186015" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186015" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178900" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178900" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:54 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 1/6] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap Date: Fri, 15 Dec 2023 22:05:31 -0800 Message-Id: <20231216060536.3716466-2-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Peter Xu , Gerd Hoffmann , Jason Gunthorpe , Junxiao Chang , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add VM_PFNMAP to vm_flags in the mmap handler to ensure that the mappings would be managed without using struct page. And, in the vm_fault handler, use vmf_insert_pfn to share the page's pfn to userspace instead of directly sharing the page (via struct page *). Cc: David Hildenbrand Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Jason Gunthorpe Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Suggested-by: David Hildenbrand Acked-by: David Hildenbrand Signed-off-by: Vivek Kasireddy --- drivers/dma-buf/udmabuf.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index c40645999648..820c993c8659 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -35,12 +35,13 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; struct udmabuf *ubuf = vma->vm_private_data; pgoff_t pgoff = vmf->pgoff; + unsigned long pfn; if (pgoff >= ubuf->pagecount) return VM_FAULT_SIGBUS; - vmf->page = ubuf->pages[pgoff]; - get_page(vmf->page); - return 0; + + pfn = page_to_pfn(ubuf->pages[pgoff]); + return vmf_insert_pfn(vma, vmf->address, pfn); } static const struct vm_operations_struct udmabuf_vm_ops = { @@ -56,6 +57,7 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) vma->vm_ops = &udmabuf_vm_ops; vma->vm_private_data = ubuf; + vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); return 0; } From patchwork Sat Dec 16 06:05:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495488 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 82B8DC38147 for ; Sat, 16 Dec 2023 06:29:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4201710E077; Sat, 16 Dec 2023 06:29:03 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0F79010E06F for ; Sat, 16 Dec 2023 06:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708136; x=1734244136; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=O1c3JIhGATN1dxcRTvUuRK9RhQSZEkJPgfU5c33zkAo=; b=bA3t7N/LKSJgOTBdCQpjXq/z5YjCXiRUCb0zl7j5P+/V26Id4KAfcRHp dQLTyxchh8BfY7NsVUdfCzgtu8+dyra8aBYDcqI31zogHTa6/IFtWjzLn v4nqIQQSJvjuY9N9oSkNz9KRMY7PI6PGIx6iTs0mxwysLIBnQQsVsodtk U7vqF8crMbdaOJgJwBnAkg0p/MHrUlT69spB9YV/Gs6TjzT4cFwFUx3rr dDDTOj3oXtVZkshRwk6FVCtLZwS97oMIR8PR17GXyGJh0/5RJ0GQA4jdH 6ZAWrpaB7wuicBH3l8LYp0M/DK55JqQSXo4rfliecuKMBoJIo558cMJUv w==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186023" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186023" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178906" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178906" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:55 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 2/6] udmabuf: Add back support for mapping hugetlb pages (v6) Date: Fri, 15 Dec 2023 22:05:32 -0800 Message-Id: <20231216060536.3716466-3-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Peter Xu , Gerd Hoffmann , Jason Gunthorpe , Junxiao Chang , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" A user or admin can configure a VMM (Qemu) Guest's memory to be backed by hugetlb pages for various reasons. However, a Guest OS would still allocate (and pin) buffers that are backed by regular 4k sized pages. In order to map these buffers and create dma-bufs for them on the Host, we first need to find the hugetlb pages where the buffer allocations are located and then determine the offsets of individual chunks (within those pages) and use this information to eventually populate a scatterlist. Testcase: default_hugepagesz=2M hugepagesz=2M hugepages=2500 options were passed to the Host kernel and Qemu was launched with these relevant options: qemu-system-x86_64 -m 4096m.... -device virtio-gpu-pci,max_outputs=1,blob=true,xres=1920,yres=1080 -display gtk,gl=on -object memory-backend-memfd,hugetlb=on,id=mem1,size=4096M -machine memory-backend=mem1 Replacing -display gtk,gl=on with -display gtk,gl=off above would exercise the mmap handler. v2: Updated get_sg_table() to manually populate the scatterlist for both huge page and non-huge-page cases. v3: s/offsets/subpgoff/g s/hpoff/mapidx/g v4: Replaced find_get_page_flags() with __filemap_get_folio() to ensure that we only obtain head pages from the mapping v5: Fix the calculation of mapidx to ensure that it is a order-n page multiple v6: - Split the processing of hugetlb or shmem pages into helpers to simplify the code in udmabuf_create() (Christoph) - Move the creation of offsets array out of hugetlb context and into common code Cc: David Hildenbrand Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Jason Gunthorpe Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Acked-by: Mike Kravetz (v2) Signed-off-by: Vivek Kasireddy --- drivers/dma-buf/udmabuf.c | 122 +++++++++++++++++++++++++++++++------- 1 file changed, 101 insertions(+), 21 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 820c993c8659..274defd3fa3e 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -28,6 +29,7 @@ struct udmabuf { struct page **pages; struct sg_table *sg; struct miscdevice *device; + pgoff_t *offsets; }; static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) @@ -41,6 +43,8 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) return VM_FAULT_SIGBUS; pfn = page_to_pfn(ubuf->pages[pgoff]); + pfn += ubuf->offsets[pgoff] >> PAGE_SHIFT; + return vmf_insert_pfn(vma, vmf->address, pfn); } @@ -90,23 +94,29 @@ static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf, { struct udmabuf *ubuf = buf->priv; struct sg_table *sg; + struct scatterlist *sgl; + unsigned int i = 0; int ret; sg = kzalloc(sizeof(*sg), GFP_KERNEL); if (!sg) return ERR_PTR(-ENOMEM); - ret = sg_alloc_table_from_pages(sg, ubuf->pages, ubuf->pagecount, - 0, ubuf->pagecount << PAGE_SHIFT, - GFP_KERNEL); + + ret = sg_alloc_table(sg, ubuf->pagecount, GFP_KERNEL); if (ret < 0) - goto err; + goto err_alloc; + + for_each_sg(sg->sgl, sgl, ubuf->pagecount, i) + sg_set_page(sgl, ubuf->pages[i], PAGE_SIZE, ubuf->offsets[i]); + ret = dma_map_sgtable(dev, sg, direction, 0); if (ret < 0) - goto err; + goto err_map; return sg; -err: +err_map: sg_free_table(sg); +err_alloc: kfree(sg); return ERR_PTR(ret); } @@ -143,6 +153,7 @@ static void release_udmabuf(struct dma_buf *buf) for (pg = 0; pg < ubuf->pagecount; pg++) put_page(ubuf->pages[pg]); + kfree(ubuf->offsets); kfree(ubuf->pages); kfree(ubuf); } @@ -196,17 +207,77 @@ static const struct dma_buf_ops udmabuf_ops = { #define SEALS_WANTED (F_SEAL_SHRINK) #define SEALS_DENIED (F_SEAL_WRITE) +static int handle_hugetlb_pages(struct udmabuf *ubuf, struct file *memfd, + pgoff_t offset, pgoff_t pgcnt, + pgoff_t *pgbuf) +{ + struct hstate *hpstate = hstate_file(memfd); + pgoff_t mapidx = offset >> huge_page_shift(hpstate); + pgoff_t subpgoff = (offset & ~huge_page_mask(hpstate)) >> PAGE_SHIFT; + pgoff_t maxsubpgs = huge_page_size(hpstate) >> PAGE_SHIFT; + struct page *hpage = NULL; + struct folio *folio; + pgoff_t pgidx; + + mapidx <<= huge_page_order(hpstate); + for (pgidx = 0; pgidx < pgcnt; pgidx++) { + if (!hpage) { + folio = __filemap_get_folio(memfd->f_mapping, + mapidx, + FGP_ACCESSED, 0); + if (IS_ERR(folio)) + return PTR_ERR(folio); + + hpage = &folio->page; + } + + get_page(hpage); + ubuf->pages[*pgbuf] = hpage; + ubuf->offsets[*pgbuf] = subpgoff << PAGE_SHIFT; + (*pgbuf)++; + if (++subpgoff == maxsubpgs) { + put_page(hpage); + hpage = NULL; + subpgoff = 0; + mapidx += pages_per_huge_page(hpstate); + } + } + + if (hpage) + put_page(hpage); + + return 0; +} + +static int handle_shmem_pages(struct udmabuf *ubuf, struct file *memfd, + pgoff_t offset, pgoff_t pgcnt, + pgoff_t *pgbuf) +{ + pgoff_t pgidx, pgoff = offset >> PAGE_SHIFT; + struct page *page; + + for (pgidx = 0; pgidx < pgcnt; pgidx++) { + page = shmem_read_mapping_page(memfd->f_mapping, + pgoff + pgidx); + if (IS_ERR(page)) + return PTR_ERR(page); + + ubuf->pages[*pgbuf] = page; + (*pgbuf)++; + } + + return 0; +} + static long udmabuf_create(struct miscdevice *device, struct udmabuf_create_list *head, struct udmabuf_create_item *list) { DEFINE_DMA_BUF_EXPORT_INFO(exp_info); struct file *memfd = NULL; - struct address_space *mapping = NULL; struct udmabuf *ubuf; struct dma_buf *buf; - pgoff_t pgoff, pgcnt, pgidx, pgbuf = 0, pglimit; - struct page *page; + pgoff_t pgcnt, pgbuf = 0, pglimit; int seals, ret = -EINVAL; u32 i, flags; @@ -234,6 +305,12 @@ static long udmabuf_create(struct miscdevice *device, ret = -ENOMEM; goto err; } + ubuf->offsets = kcalloc(ubuf->pagecount, sizeof(*ubuf->offsets), + GFP_KERNEL); + if (!ubuf->offsets) { + ret = -ENOMEM; + goto err; + } pgbuf = 0; for (i = 0; i < head->count; i++) { @@ -241,8 +318,7 @@ static long udmabuf_create(struct miscdevice *device, memfd = fget(list[i].memfd); if (!memfd) goto err; - mapping = memfd->f_mapping; - if (!shmem_mapping(mapping)) + if (!shmem_file(memfd) && !is_file_hugepages(memfd)) goto err; seals = memfd_fcntl(memfd, F_GET_SEALS, 0); if (seals == -EINVAL) @@ -251,16 +327,19 @@ static long udmabuf_create(struct miscdevice *device, if ((seals & SEALS_WANTED) != SEALS_WANTED || (seals & SEALS_DENIED) != 0) goto err; - pgoff = list[i].offset >> PAGE_SHIFT; - pgcnt = list[i].size >> PAGE_SHIFT; - for (pgidx = 0; pgidx < pgcnt; pgidx++) { - page = shmem_read_mapping_page(mapping, pgoff + pgidx); - if (IS_ERR(page)) { - ret = PTR_ERR(page); - goto err; - } - ubuf->pages[pgbuf++] = page; - } + + pgcnt = list[i].size >> PAGE_SHIFT; + if (is_file_hugepages(memfd)) + ret = handle_hugetlb_pages(ubuf, memfd, + list[i].offset, + pgcnt, &pgbuf); + else + ret = handle_shmem_pages(ubuf, memfd, + list[i].offset, + pgcnt, &pgbuf); + if (ret < 0) + goto err; + fput(memfd); memfd = NULL; } @@ -287,6 +366,7 @@ static long udmabuf_create(struct miscdevice *device, put_page(ubuf->pages[--pgbuf]); if (memfd) fput(memfd); + kfree(ubuf->offsets); kfree(ubuf->pages); kfree(ubuf); return ret; From patchwork Sat Dec 16 06:05:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495490 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5BE2C4167B for ; Sat, 16 Dec 2023 06:29:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 11CF810E32C; Sat, 16 Dec 2023 06:29:04 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id D051810E06F for ; Sat, 16 Dec 2023 06:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708137; x=1734244137; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=y7c0p+lPK1aglp77lTkz3x2+xm9XiI7T8TRoE4cz9K8=; b=PTQJ2MIgmgWSp2p/6MEF6hH7ofqUHxQpxU/teFki9zw1xOCOOYNLObVn 6b4FlfRE/aeFIkNuL6+yvi0QbEqUgb3+DR1hkyX6zWcQsoD//68udSlik YLahbIbBhplvMKmCzh/1ATfIMlF2GDHpZGfksRETEnB4lGvN3Frwe/2F0 dTdfwje3IRwdUvGKowWrMS8tjChL4aqIHxzlU+rmPHxGZeSkrvzcptMKS 3XEDNTsmtfHKj6Q0BHXY/wNmZBbQRVsv+Dq/XGH+v2Z50hajGdoYOMFxQ pRljeWVWpFGBzUWxgm4EnWyFP+u2H1uaJcXRA3tg5zuuxRXXOJ2Z7MuRE w==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186030" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186030" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178910" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178910" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:55 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 3/6] mm/gup: Introduce memfd_pin_folios() for pinning memfd folios (v8) Date: Fri, 15 Dec 2023 22:05:33 -0800 Message-Id: <20231216060536.3716466-4-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Peter Xu , Christoph Hellwig , Gerd Hoffmann , Jason Gunthorpe , Junxiao Chang , Christoph Hellwig , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" For drivers that would like to longterm-pin the folios associated with a memfd, the memfd_pin_folios() API provides an option to not only pin the folios via FOLL_PIN but also to check and migrate them if they reside in movable zone or CMA block. This API currently works with memfds but it should work with any files that belong to either shmemfs or hugetlbfs. Files belonging to other filesystems are rejected for now. The folios need to be located first before pinning them via FOLL_PIN. If they are found in the page cache, they can be immediately pinned. Otherwise, they need to be allocated using the filesystem specific APIs and then pinned. v2: - Drop gup_flags and improve comments and commit message (David) - Allocate a page if we cannot find in page cache for the hugetlbfs case as well (David) - Don't unpin pages if there is a migration related failure (David) - Drop the unnecessary nr_pages <= 0 check (Jason) - Have the caller of the API pass in file * instead of fd (Jason) v3: (David) - Enclose the huge page allocation code with #ifdef CONFIG_HUGETLB_PAGE (Build error reported by kernel test robot ) - Don't forget memalloc_pin_restore() on non-migration related errors - Improve the readability of the cleanup code associated with non-migration related errors - Augment the comments by describing FOLL_LONGTERM like behavior - Include the R-b tag from Jason v4: - Remove the local variable "page" and instead use 3 return statements in alloc_file_page() (David) - Add the R-b tag from David v5: (David) - For hugetlb case, ensure that we only obtain head pages from the mapping by using __filemap_get_folio() instead of find_get_page_flags() - Handle -EEXIST when two or more potential users try to simultaneously add a huge page to the mapping by forcing them to retry on failure v6: (Christoph) - Rename this API to memfd_pin_user_pages() to make it clear that it is intended for memfds - Move the memfd page allocation helper from gup.c to memfd.c - Fix indentation errors in memfd_pin_user_pages() - For contiguous ranges of folios, use a helper such as filemap_get_folios_contig() to lookup the page cache in batches v7: - Rename this API to memfd_pin_folios() and make it return folios and offsets instead of pages (David) - Don't continue processing the folios in the batch returned by filemap_get_folios_contig() if they do not have correct next_idx - Add the R-b tag from Christoph v8: (David) - Have caller pass [start, end], max_folios instead of start, nr_pages - Replace offsets array with just offset into the first page - Add comments explaning the need for next_idx - Pin (and return) the folio (via FOLL_PIN) only once Cc: David Hildenbrand Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe (v2) Reviewed-by: David Hildenbrand (v3) Reviewed-by: Christoph Hellwig (v6) Signed-off-by: Vivek Kasireddy --- include/linux/memfd.h | 5 ++ include/linux/mm.h | 3 + mm/gup.c | 149 ++++++++++++++++++++++++++++++++++++++++++ mm/memfd.c | 34 ++++++++++ 4 files changed, 191 insertions(+) diff --git a/include/linux/memfd.h b/include/linux/memfd.h index e7abf6fa4c52..b38fb35f4271 100644 --- a/include/linux/memfd.h +++ b/include/linux/memfd.h @@ -6,11 +6,16 @@ #ifdef CONFIG_MEMFD_CREATE extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg); +extern struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx); #else static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a) { return -EINVAL; } +static inline struct page *memfd_alloc_folio(struct file *memfd, pgoff_t idx) +{ + return ERR_PTR(-EINVAL); +} #endif #endif /* __LINUX_MEMFD_H */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 418d26608ece..956f0ec24598 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2472,6 +2472,9 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, struct page **pages, unsigned int gup_flags); +long memfd_pin_folios(struct file *file, loff_t start, loff_t end, + struct folio **folios, unsigned int max_folios, + unsigned long *offset); int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); diff --git a/mm/gup.c b/mm/gup.c index 231711efa390..70ae653e4109 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -17,6 +18,7 @@ #include #include #include +#include #include #include @@ -3410,3 +3412,150 @@ long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages, &locked, gup_flags); } EXPORT_SYMBOL(pin_user_pages_unlocked); + +/** + * memfd_pin_folios() - pin folios associated with a memfd + * @memfd: the memfd whose folios are to be pinned + * @start: the first memfd offset + * @end: the last memfd offset (inclusive) + * @folios: array that receives pointers to the folios pinned + * @max_folios: maximum number of entries in @folios + * @offset: the offset into the first folio + * + * Attempt to pin folios associated with a memfd in the contiguous range + * [start, end]. Given that a memfd is either backed by shmem or hugetlb, + * the folios can either be found in the page cache or need to be allocated + * if necessary. Once the folios are located, they are all pinned via + * FOLL_PIN and @offset is populatedwith the offset into the first folio. + * And, eventually, these pinned folios must be released either using + * unpin_user_pages() or unpin_user_page(). + * + * It must be noted that the folios may be pinned for an indefinite amount + * of time. And, in most cases, the duration of time they may stay pinned + * would be controlled by the userspace. This behavior is effectively the + * same as using FOLL_LONGTERM with other GUP APIs. + * + * Returns number of folios pinned, which could be less than @max_folios + * as it depends on the folio sizes that cover the range [start, end]. + * If no folios were pinned, it returns -errno. + */ +long memfd_pin_folios(struct file *memfd, loff_t start, loff_t end, + struct folio **folios, unsigned int max_folios, + unsigned long *offset) +{ + unsigned int flags, nr_folios, nr_found; + unsigned int i, pgshift = PAGE_SHIFT; + pgoff_t start_idx, end_idx, next_idx; + struct folio *folio = NULL; + struct folio_batch fbatch; + struct page **pages; + struct hstate *h; + long ret; + + if (start > end || !max_folios) + return -EINVAL; + + if (!memfd) + return -EINVAL; + + if (!shmem_file(memfd) && !is_file_hugepages(memfd)) + return -EINVAL; + + pages = kmalloc_array(max_folios, sizeof(*pages), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + if (is_file_hugepages(memfd)) { + h = hstate_file(memfd); + pgshift = huge_page_shift(h); + } + + flags = memalloc_pin_save(); + do { + nr_folios = 0; + start_idx = start >> pgshift; + end_idx = end >> pgshift; + if (is_file_hugepages(memfd)) { + start_idx <<= huge_page_order(h); + end_idx <<= huge_page_order(h); + } + + folio_batch_init(&fbatch); + while (start_idx <= end_idx && nr_folios < max_folios) { + /* + * In most cases, we should be able to find the folios + * in the page cache. If we cannot find them for some + * reason, we try to allocate them and add them to the + * page cache. + */ + nr_found = filemap_get_folios_contig(memfd->f_mapping, + &start_idx, + end_idx, + &fbatch); + if (folio) { + folio_put(folio); + folio = NULL; + } + + next_idx = 0; + for (i = 0; i < nr_found; i++) { + /* + * As there can be multiple entries for a + * given folio in the batch returned by + * filemap_get_folios_contig(), the below + * check is to ensure that we pin and return a + * unique set of folios between start and end. + */ + if (next_idx && + next_idx != folio_index(fbatch.folios[i])) + continue; + + folio = try_grab_folio(&fbatch.folios[i]->page, + 1, FOLL_PIN); + if (!folio) { + folio_batch_release(&fbatch); + kfree(pages); + goto err; + } + + if (nr_folios == 0) + *offset = offset_in_folio(folio, start); + + folios[nr_folios] = folio; + pages[nr_folios] = folio_page(folio, 0); + next_idx = folio_next_index(folio); + + if (++nr_folios == max_folios) + break; + } + + folio = NULL; + folio_batch_release(&fbatch); + if (!nr_found) { + folio = memfd_alloc_folio(memfd, start_idx); + if (IS_ERR(folio)) { + ret = PTR_ERR(folio); + if (ret != -EEXIST) { + kfree(pages); + goto err; + } + } + } + } + + ret = check_and_migrate_movable_pages(nr_folios, pages); + } while (ret == -EAGAIN); + + kfree(pages); + memalloc_pin_restore(flags); + return ret ? ret : nr_folios; +err: + memalloc_pin_restore(flags); + while (i-- > 0) + if (folios[i]) + gup_put_folio(folios[i], 1, FOLL_PIN); + + return ret; +} +EXPORT_SYMBOL_GPL(memfd_pin_folios); + diff --git a/mm/memfd.c b/mm/memfd.c index d3a1ba4208c9..36a75e8249f8 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -63,6 +63,40 @@ static void memfd_tag_pins(struct xa_state *xas) xas_unlock_irq(xas); } +/* + * This is a helper function used by memfd_pin_user_pages() in GUP (gup.c). + * It is mainly called to allocate a page in a memfd when the caller + * (memfd_pin_user_pages()) cannot find a page in the page cache at a given + * index in the mapping. + */ +struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx) +{ +#ifdef CONFIG_HUGETLB_PAGE + struct folio *folio; + int err; + + if (is_file_hugepages(memfd)) { + folio = alloc_hugetlb_folio_nodemask(hstate_file(memfd), + NUMA_NO_NODE, + NULL, + GFP_USER); + if (folio && folio_try_get(folio)) { + err = hugetlb_add_to_page_cache(folio, + memfd->f_mapping, + idx); + if (err) { + folio_put(folio); + free_huge_folio(folio); + return ERR_PTR(err); + } + return folio; + } + return ERR_PTR(-ENOMEM); + } +#endif + return shmem_read_folio(memfd->f_mapping, idx); +} + /* * Setting SEAL_WRITE requires us to verify there's no pending writer. However, * via get_user_pages(), drivers might have some pending I/O without any active From patchwork Sat Dec 16 06:05:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495492 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48053C46CA2 for ; Sat, 16 Dec 2023 06:29:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BBFE910EADA; Sat, 16 Dec 2023 06:29:20 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4BE8310E077 for ; Sat, 16 Dec 2023 06:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708137; x=1734244137; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=srh+pDeiF4x93Sp9cmg48dB8ma2fshhkeNl1Nqm5xC4=; b=BmYnnPy1e+EL74Yu7ozD9kXnYHw4rB6+X89z+/UUguufvYCDqz9CR7B2 3Ek5pFz3E3Vbt4rK4UeXnguSjnu8Tdb4uAUnJso/O+APp2ZQBs0o29j6/ Oj1I9L2W06yNFHW9j9GuMCet2d2gw5YPx+/R8ts2h3Sv0Af4m9fFHZyu2 hke2j7hBzky4ygcsRkPx7j6UiECNlh+vZQgZ0oSly5zi0pHKnsNvOJy1H 6RijtlWbIIitXrC/XUYc5uBOmpsd+ra7pGX9olk42FnHiIiY8BuAN3hrd Z83R9hZeQtM8WBIAk40YPWu+e10GmYVqNIURDZj8d124llHH/D7iMhCXB A==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186039" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186039" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:57 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178913" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178913" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:56 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 4/6] udmabuf: Convert udmabuf driver to use folios (v2) Date: Fri, 15 Dec 2023 22:05:34 -0800 Message-Id: <20231216060536.3716466-5-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gerd Hoffmann , Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Matthew Wilcox , Peter Xu , Jason Gunthorpe , Junxiao Chang , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This is mainly a preparatory patch to use memfd_pin_folios() API for pinning folios. Using folios instead of pages makes sense as the udmabuf driver needs to handle both shmem and hugetlb cases. However, the function vmap_udmabuf() still needs a list of pages; so, we collect all the head pages into a local array in this case. Other changes in this patch include the addition of helpers for checking the memfd seals and exporting dmabuf. Moving code from udmabuf_create() into these helpers improves readability given that udmabuf_create() is a bit long. v2: (Matthew) - Use folio_pfn() on the folio instead of page_to_pfn() on head page - Don't split the arguments to shmem_read_folio() on multiple lines Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Jason Gunthorpe Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Signed-off-by: Vivek Kasireddy --- drivers/dma-buf/udmabuf.c | 140 ++++++++++++++++++++++---------------- 1 file changed, 83 insertions(+), 57 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 274defd3fa3e..a8f3af61f7f2 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -26,7 +26,7 @@ MODULE_PARM_DESC(size_limit_mb, "Max size of a dmabuf, in megabytes. Default is struct udmabuf { pgoff_t pagecount; - struct page **pages; + struct folio **folios; struct sg_table *sg; struct miscdevice *device; pgoff_t *offsets; @@ -42,7 +42,7 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) if (pgoff >= ubuf->pagecount) return VM_FAULT_SIGBUS; - pfn = page_to_pfn(ubuf->pages[pgoff]); + pfn = folio_pfn(ubuf->folios[pgoff]); pfn += ubuf->offsets[pgoff] >> PAGE_SHIFT; return vmf_insert_pfn(vma, vmf->address, pfn); @@ -68,11 +68,21 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map) { struct udmabuf *ubuf = buf->priv; + struct page **pages; void *vaddr; + pgoff_t pg; dma_resv_assert_held(buf->resv); - vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1); + pages = kmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + for (pg = 0; pg < ubuf->pagecount; pg++) + pages[pg] = &ubuf->folios[pg]->page; + + vaddr = vm_map_ram(pages, ubuf->pagecount, -1); + kfree(pages); if (!vaddr) return -EINVAL; @@ -107,7 +117,8 @@ static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf, goto err_alloc; for_each_sg(sg->sgl, sgl, ubuf->pagecount, i) - sg_set_page(sgl, ubuf->pages[i], PAGE_SIZE, ubuf->offsets[i]); + sg_set_folio(sgl, ubuf->folios[i], PAGE_SIZE, + ubuf->offsets[i]); ret = dma_map_sgtable(dev, sg, direction, 0); if (ret < 0) @@ -152,9 +163,9 @@ static void release_udmabuf(struct dma_buf *buf) put_sg_table(dev, ubuf->sg, DMA_BIDIRECTIONAL); for (pg = 0; pg < ubuf->pagecount; pg++) - put_page(ubuf->pages[pg]); + folio_put(ubuf->folios[pg]); kfree(ubuf->offsets); - kfree(ubuf->pages); + kfree(ubuf->folios); kfree(ubuf); } @@ -215,36 +226,33 @@ static int handle_hugetlb_pages(struct udmabuf *ubuf, struct file *memfd, pgoff_t mapidx = offset >> huge_page_shift(hpstate); pgoff_t subpgoff = (offset & ~huge_page_mask(hpstate)) >> PAGE_SHIFT; pgoff_t maxsubpgs = huge_page_size(hpstate) >> PAGE_SHIFT; - struct page *hpage = NULL; - struct folio *folio; + struct folio *folio = NULL; pgoff_t pgidx; mapidx <<= huge_page_order(hpstate); for (pgidx = 0; pgidx < pgcnt; pgidx++) { - if (!hpage) { + if (!folio) { folio = __filemap_get_folio(memfd->f_mapping, mapidx, FGP_ACCESSED, 0); if (IS_ERR(folio)) return PTR_ERR(folio); - - hpage = &folio->page; } - get_page(hpage); - ubuf->pages[*pgbuf] = hpage; + folio_get(folio); + ubuf->folios[*pgbuf] = folio; ubuf->offsets[*pgbuf] = subpgoff << PAGE_SHIFT; (*pgbuf)++; if (++subpgoff == maxsubpgs) { - put_page(hpage); - hpage = NULL; + folio_put(folio); + folio = NULL; subpgoff = 0; mapidx += pages_per_huge_page(hpstate); } } - if (hpage) - put_page(hpage); + if (folio) + folio_put(folio); return 0; } @@ -254,31 +262,69 @@ static int handle_shmem_pages(struct udmabuf *ubuf, struct file *memfd, pgoff_t *pgbuf) { pgoff_t pgidx, pgoff = offset >> PAGE_SHIFT; - struct page *page; + struct folio *folio = NULL; for (pgidx = 0; pgidx < pgcnt; pgidx++) { - page = shmem_read_mapping_page(memfd->f_mapping, - pgoff + pgidx); - if (IS_ERR(page)) - return PTR_ERR(page); + folio = shmem_read_folio(memfd->f_mapping, pgoff + pgidx); + if (IS_ERR(folio)) + return PTR_ERR(folio); - ubuf->pages[*pgbuf] = page; + ubuf->folios[*pgbuf] = folio; (*pgbuf)++; } return 0; } +static int check_memfd_seals(struct file *memfd) +{ + int seals; + + if (!memfd) + return -EBADFD; + + if (!shmem_file(memfd) && !is_file_hugepages(memfd)) + return -EBADFD; + + seals = memfd_fcntl(memfd, F_GET_SEALS, 0); + if (seals == -EINVAL) + return -EBADFD; + + if ((seals & SEALS_WANTED) != SEALS_WANTED || + (seals & SEALS_DENIED) != 0) + return -EINVAL; + + return 0; +} + +static int export_udmabuf(struct udmabuf *ubuf, + struct miscdevice *device, + u32 flags) +{ + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + struct dma_buf *buf; + + ubuf->device = device; + exp_info.ops = &udmabuf_ops; + exp_info.size = ubuf->pagecount << PAGE_SHIFT; + exp_info.priv = ubuf; + exp_info.flags = O_RDWR; + + buf = dma_buf_export(&exp_info); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + return dma_buf_fd(buf, flags); +} + static long udmabuf_create(struct miscdevice *device, struct udmabuf_create_list *head, struct udmabuf_create_item *list) { - DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + pgoff_t pgcnt, pgbuf = 0, pglimit; struct file *memfd = NULL; struct udmabuf *ubuf; - struct dma_buf *buf; - pgoff_t pgcnt, pgbuf = 0, pglimit; - int seals, ret = -EINVAL; + int ret = -EINVAL; u32 i, flags; ubuf = kzalloc(sizeof(*ubuf), GFP_KERNEL); @@ -299,9 +345,9 @@ static long udmabuf_create(struct miscdevice *device, if (!ubuf->pagecount) goto err; - ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages), + ubuf->folios = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->folios), GFP_KERNEL); - if (!ubuf->pages) { + if (!ubuf->folios) { ret = -ENOMEM; goto err; } @@ -314,18 +360,9 @@ static long udmabuf_create(struct miscdevice *device, pgbuf = 0; for (i = 0; i < head->count; i++) { - ret = -EBADFD; memfd = fget(list[i].memfd); - if (!memfd) - goto err; - if (!shmem_file(memfd) && !is_file_hugepages(memfd)) - goto err; - seals = memfd_fcntl(memfd, F_GET_SEALS, 0); - if (seals == -EINVAL) - goto err; - ret = -EINVAL; - if ((seals & SEALS_WANTED) != SEALS_WANTED || - (seals & SEALS_DENIED) != 0) + ret = check_memfd_seals(memfd); + if (ret < 0) goto err; pgcnt = list[i].size >> PAGE_SHIFT; @@ -341,33 +378,22 @@ static long udmabuf_create(struct miscdevice *device, goto err; fput(memfd); - memfd = NULL; } - exp_info.ops = &udmabuf_ops; - exp_info.size = ubuf->pagecount << PAGE_SHIFT; - exp_info.priv = ubuf; - exp_info.flags = O_RDWR; - - ubuf->device = device; - buf = dma_buf_export(&exp_info); - if (IS_ERR(buf)) { - ret = PTR_ERR(buf); + flags = head->flags & UDMABUF_FLAGS_CLOEXEC ? O_CLOEXEC : 0; + ret = export_udmabuf(ubuf, device, flags); + if (ret < 0) goto err; - } - flags = 0; - if (head->flags & UDMABUF_FLAGS_CLOEXEC) - flags |= O_CLOEXEC; - return dma_buf_fd(buf, flags); + return ret; err: while (pgbuf > 0) - put_page(ubuf->pages[--pgbuf]); + folio_put(ubuf->folios[--pgbuf]); if (memfd) fput(memfd); kfree(ubuf->offsets); - kfree(ubuf->pages); + kfree(ubuf->folios); kfree(ubuf); return ret; } From patchwork Sat Dec 16 06:05:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495491 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0A935C4167B for ; Sat, 16 Dec 2023 06:29:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6D5CB10EA7B; Sat, 16 Dec 2023 06:29:19 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id B6E1510E077 for ; Sat, 16 Dec 2023 06:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708138; x=1734244138; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KZifQoWRpsSYXJ0ERWQORaReoIuSKvbcn4vSOcCzi/s=; b=jrYmn4jQcTADvv85JwLO/cEykOiufPdsWENorbhQ8f509UMgsVOR2vP8 kA8s/IJGsh3sSQ0+X+6R9DFE5Hgk48jd/D60cCP7J5out/vL/+zgh8iWC oyx/W/vnKY8+uY0J4yRI9tgusisz0WEO+eBe0C/lm4c1xfmpDYAszZcWE q8lAr+JSlNP6OagQAQrDUEysyn8uuYYCyLcFUHcNr++5dlrcd6KPyXhOc uVjLeyrJvGTTuqWNkZvuAmH0I8+QaD7JKdGPGZi4Z5s2GwzLwEIoyGI0A 2C5LMSynbp3YrZHXxmuJtvOo9QdlEZs5A5MTAz57gW14kaD9Xco571ucj g==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186048" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186048" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:57 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178916" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178916" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:56 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 5/6] udmabuf: Pin the pages using memfd_pin_folios() API (v6) Date: Fri, 15 Dec 2023 22:05:35 -0800 Message-Id: <20231216060536.3716466-6-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gerd Hoffmann , Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Matthew Wilcox , Peter Xu , Jason Gunthorpe , Junxiao Chang , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Using memfd_pin_folios() will ensure that the pages are pinned correctly using FOLL_PIN. And, this also ensures that we don't accidentally break features such as memory hotunplug as it would not allow pinning pages in the movable zone. Using this new API also simplifies the code as we no longer have to deal with extracting individual pages from their mappings or handle shmem and hugetlb cases separately. v2: - Adjust to the change in signature of pin_user_pages_fd() by passing in file * instead of fd. v3: - Limit the changes in this patch only to those that are required for using pin_user_pages_fd() - Slightly improve the commit message v4: - Adjust to the change in name of the API (memfd_pin_user_pages) v5: - Adjust to the changes in memfd_pin_folios which now populates a list of folios and offsets v6: - Don't unnecessarily use folio_page() (Matthew) - Pass [start, end] and max_folios to memfd_pin_folios() - Create another temporary array to hold the folios returned by memfd_pin_folios() as we populate ubuf->folios. - Unpin the folios only once as memfd_pin_folios pins them once Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Jason Gunthorpe Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Signed-off-by: Vivek Kasireddy --- drivers/dma-buf/udmabuf.c | 124 +++++++++++++++----------------------- 1 file changed, 49 insertions(+), 75 deletions(-) diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index a8f3af61f7f2..088f3a64e94c 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -153,17 +153,30 @@ static void unmap_udmabuf(struct dma_buf_attachment *at, return put_sg_table(at->dev, sg, direction); } +static void unpin_all_folios(struct udmabuf *ubuf, pgoff_t pgbuf) +{ + unsigned int i = 0, j; + + while (i < pgbuf) { + for (j = i + 1; j < pgbuf; j++) { + if (ubuf->folios[i] != ubuf->folios[j]) + break; + } + + unpin_user_page(&ubuf->folios[i]->page); + i = j; + } +} + static void release_udmabuf(struct dma_buf *buf) { struct udmabuf *ubuf = buf->priv; struct device *dev = ubuf->device->this_device; - pgoff_t pg; if (ubuf->sg) put_sg_table(dev, ubuf->sg, DMA_BIDIRECTIONAL); - for (pg = 0; pg < ubuf->pagecount; pg++) - folio_put(ubuf->folios[pg]); + unpin_all_folios(ubuf, ubuf->pagecount); kfree(ubuf->offsets); kfree(ubuf->folios); kfree(ubuf); @@ -218,64 +231,6 @@ static const struct dma_buf_ops udmabuf_ops = { #define SEALS_WANTED (F_SEAL_SHRINK) #define SEALS_DENIED (F_SEAL_WRITE) -static int handle_hugetlb_pages(struct udmabuf *ubuf, struct file *memfd, - pgoff_t offset, pgoff_t pgcnt, - pgoff_t *pgbuf) -{ - struct hstate *hpstate = hstate_file(memfd); - pgoff_t mapidx = offset >> huge_page_shift(hpstate); - pgoff_t subpgoff = (offset & ~huge_page_mask(hpstate)) >> PAGE_SHIFT; - pgoff_t maxsubpgs = huge_page_size(hpstate) >> PAGE_SHIFT; - struct folio *folio = NULL; - pgoff_t pgidx; - - mapidx <<= huge_page_order(hpstate); - for (pgidx = 0; pgidx < pgcnt; pgidx++) { - if (!folio) { - folio = __filemap_get_folio(memfd->f_mapping, - mapidx, - FGP_ACCESSED, 0); - if (IS_ERR(folio)) - return PTR_ERR(folio); - } - - folio_get(folio); - ubuf->folios[*pgbuf] = folio; - ubuf->offsets[*pgbuf] = subpgoff << PAGE_SHIFT; - (*pgbuf)++; - if (++subpgoff == maxsubpgs) { - folio_put(folio); - folio = NULL; - subpgoff = 0; - mapidx += pages_per_huge_page(hpstate); - } - } - - if (folio) - folio_put(folio); - - return 0; -} - -static int handle_shmem_pages(struct udmabuf *ubuf, struct file *memfd, - pgoff_t offset, pgoff_t pgcnt, - pgoff_t *pgbuf) -{ - pgoff_t pgidx, pgoff = offset >> PAGE_SHIFT; - struct folio *folio = NULL; - - for (pgidx = 0; pgidx < pgcnt; pgidx++) { - folio = shmem_read_folio(memfd->f_mapping, pgoff + pgidx); - if (IS_ERR(folio)) - return PTR_ERR(folio); - - ubuf->folios[*pgbuf] = folio; - (*pgbuf)++; - } - - return 0; -} - static int check_memfd_seals(struct file *memfd) { int seals; @@ -321,11 +276,13 @@ static long udmabuf_create(struct miscdevice *device, struct udmabuf_create_list *head, struct udmabuf_create_item *list) { - pgoff_t pgcnt, pgbuf = 0, pglimit; + pgoff_t pgoff, pgcnt, pglimit, pgbuf = 0; + long nr_folios, ret = -EINVAL; struct file *memfd = NULL; + struct folio **folios; struct udmabuf *ubuf; - int ret = -EINVAL; - u32 i, flags; + u32 i, j, k, flags; + loff_t end; ubuf = kzalloc(sizeof(*ubuf), GFP_KERNEL); if (!ubuf) @@ -366,17 +323,35 @@ static long udmabuf_create(struct miscdevice *device, goto err; pgcnt = list[i].size >> PAGE_SHIFT; - if (is_file_hugepages(memfd)) - ret = handle_hugetlb_pages(ubuf, memfd, - list[i].offset, - pgcnt, &pgbuf); - else - ret = handle_shmem_pages(ubuf, memfd, - list[i].offset, - pgcnt, &pgbuf); - if (ret < 0) + folios = kmalloc_array(pgcnt, sizeof(*folios), GFP_KERNEL); + if (!folios) { + ret = -ENOMEM; goto err; + } + end = list[i].offset + (pgcnt << PAGE_SHIFT) - 1; + ret = memfd_pin_folios(memfd, list[i].offset, end, + folios, pgcnt, &pgoff); + if (ret < 0) { + kfree(folios); + goto err; + } + + nr_folios = ret; + pgoff >>= PAGE_SHIFT; + for (j = 0, k = 0; j < pgcnt; j++) { + ubuf->folios[pgbuf] = folios[k]; + ubuf->offsets[pgbuf] = pgoff << PAGE_SHIFT; + pgbuf++; + + if (++pgoff == folio_nr_pages(folios[k])) { + pgoff = 0; + if (++k == nr_folios) + break; + } + } + + kfree(folios); fput(memfd); } @@ -388,10 +363,9 @@ static long udmabuf_create(struct miscdevice *device, return ret; err: - while (pgbuf > 0) - folio_put(ubuf->folios[--pgbuf]); if (memfd) fput(memfd); + unpin_all_folios(ubuf, pgbuf); kfree(ubuf->offsets); kfree(ubuf->folios); kfree(ubuf); From patchwork Sat Dec 16 06:05:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13495489 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3F680C4167B for ; Sat, 16 Dec 2023 06:29:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0D89D10E328; Sat, 16 Dec 2023 06:29:04 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 34B9B10E328 for ; Sat, 16 Dec 2023 06:28:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702708138; x=1734244138; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=r39C9fURv/tYjjTgfRvVfOiacLkGBXJF65fG2x4l+b0=; b=HGUKxw0tk27gHRw8dZ22BwK6aoUKwo3SoSbfTv79iQSQjP8EPs6a+oCx 1YKz/66qhbpjFuXSRam2CZPU/L4kWWcUNxBRzZxIC568QEz/8cWpZHerW 89MFW2uTL/O8cANraYFAbqWIRBQZlyuL/oVsZr2iXadyKqnVoag9dw2IL PscJtpA0Jiqzf/ZeN7eVjiJaR1C6aWBujKrDr9l9ONacg/lE9H9TcACsr O0ER1QGMezldqFDybX3nyr8WHa6F57tkTy1iDd6SA8dmkVaUW+w7f50Un EtJhTcAZqKu5R/+9eoh14D10eMUvZ9fnUdRHYoXzAUKiGS+SgafKPEiz0 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="2186057" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="2186057" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10925"; a="751178920" X-IronPort-AV: E=Sophos;i="6.04,280,1695711600"; d="scan'208";a="751178920" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2023 22:28:57 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v8 6/6] selftests/dma-buf/udmabuf: Add tests to verify data after page migration Date: Fri, 15 Dec 2023 22:05:36 -0800 Message-Id: <20231216060536.3716466-7-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231216060536.3716466-1-vivek.kasireddy@intel.com> References: <20231216060536.3716466-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dongwon Kim , David Hildenbrand , Daniel Vetter , Hugh Dickins , Vivek Kasireddy , Peter Xu , Gerd Hoffmann , Jason Gunthorpe , Junxiao Chang , Shuah Khan , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Since the memfd pages associated with a udmabuf may be migrated as part of udmabuf create, we need to verify the data coherency after successful migration. The new tests added in this patch try to do just that using 4k sized pages and also 2 MB sized huge pages for the memfd. Successful completion of the tests would mean that there is no disconnect between the memfd pages and the ones associated with a udmabuf. And, these tests can also be augmented in the future to test newer udmabuf features (such as handling memfd hole punch). Cc: Shuah Khan Cc: David Hildenbrand Cc: Daniel Vetter Cc: Mike Kravetz Cc: Hugh Dickins Cc: Peter Xu Cc: Jason Gunthorpe Cc: Gerd Hoffmann Cc: Dongwon Kim Cc: Junxiao Chang Based-on-patch-by: Mike Kravetz Signed-off-by: Vivek Kasireddy --- .../selftests/drivers/dma-buf/udmabuf.c | 151 +++++++++++++++++- 1 file changed, 147 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/drivers/dma-buf/udmabuf.c b/tools/testing/selftests/drivers/dma-buf/udmabuf.c index c812080e304e..d76c813fe652 100644 --- a/tools/testing/selftests/drivers/dma-buf/udmabuf.c +++ b/tools/testing/selftests/drivers/dma-buf/udmabuf.c @@ -9,26 +9,132 @@ #include #include #include +#include #include #include +#include #include #include #define TEST_PREFIX "drivers/dma-buf/udmabuf" #define NUM_PAGES 4 +#define NUM_ENTRIES 4 +#define MEMFD_SIZE 1024 /* in pages */ -static int memfd_create(const char *name, unsigned int flags) +static unsigned int page_size; + +static int create_memfd_with_seals(off64_t size, bool hpage) +{ + int memfd, ret; + unsigned int flags = MFD_ALLOW_SEALING; + + if (hpage) + flags |= MFD_HUGETLB; + + memfd = memfd_create("udmabuf-test", flags); + if (memfd < 0) { + printf("%s: [skip,no-memfd]\n", TEST_PREFIX); + exit(77); + } + + ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); + if (ret < 0) { + printf("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX); + exit(77); + } + + ret = ftruncate(memfd, size); + if (ret == -1) { + printf("%s: [FAIL,memfd-truncate]\n", TEST_PREFIX); + exit(1); + } + + return memfd; +} + +static int create_udmabuf_list(int devfd, int memfd, off64_t memfd_size) +{ + struct udmabuf_create_list *list; + int ubuf_fd, i; + + list = malloc(sizeof(struct udmabuf_create_list) + + sizeof(struct udmabuf_create_item) * NUM_ENTRIES); + if (!list) { + printf("%s: [FAIL, udmabuf-malloc]\n", TEST_PREFIX); + exit(1); + } + + for (i = 0; i < NUM_ENTRIES; i++) { + list->list[i].memfd = memfd; + list->list[i].offset = i * (memfd_size / NUM_ENTRIES); + list->list[i].size = getpagesize() * NUM_PAGES; + } + + list->count = NUM_ENTRIES; + list->flags = UDMABUF_FLAGS_CLOEXEC; + ubuf_fd = ioctl(devfd, UDMABUF_CREATE_LIST, list); + free(list); + if (ubuf_fd < 0) { + printf("%s: [FAIL, udmabuf-create]\n", TEST_PREFIX); + exit(1); + } + + return ubuf_fd; +} + +static void write_to_memfd(void *addr, off64_t size, char chr) +{ + int i; + + for (i = 0; i < size / page_size; i++) { + *((char *)addr + (i * page_size)) = chr; + } +} + +static void *mmap_fd(int fd, off64_t size) { - return syscall(__NR_memfd_create, name, flags); + void *addr; + + addr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) { + printf("%s: ubuf_fd mmap fail\n", TEST_PREFIX); + exit(1); + } + + return addr; +} + +static int compare_chunks(void *addr1, void *addr2, off64_t memfd_size) +{ + off64_t off; + int i = 0, j, k = 0, ret = 0; + char char1, char2; + + while (i < NUM_ENTRIES) { + off = i * (memfd_size / NUM_ENTRIES); + for (j = 0; j < NUM_PAGES; j++, k++) { + char1 = *((char *)addr1 + off + (j * getpagesize())); + char2 = *((char *)addr2 + (k * getpagesize())); + if (char1 != char2) { + ret = -1; + goto err; + } + } + i++; + } +err: + munmap(addr1, memfd_size); + munmap(addr2, NUM_ENTRIES * NUM_PAGES * getpagesize()); + return ret; } int main(int argc, char *argv[]) { struct udmabuf_create create; int devfd, memfd, buf, ret; - off_t size; - void *mem; + off64_t size; + void *addr1, *addr2; devfd = open("/dev/udmabuf", O_RDWR); if (devfd < 0) { @@ -90,6 +196,9 @@ int main(int argc, char *argv[]) } /* should work */ + page_size = getpagesize(); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); create.memfd = memfd; create.offset = 0; create.size = size; @@ -98,6 +207,40 @@ int main(int argc, char *argv[]) printf("%s: [FAIL,test-4]\n", TEST_PREFIX); exit(1); } + munmap(addr1, size); + close(buf); + close(memfd); + + /* should work (migration of 4k size pages)*/ + size = MEMFD_SIZE * page_size; + memfd = create_memfd_with_seals(size, false); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); + buf = create_udmabuf_list(devfd, memfd, size); + addr2 = mmap_fd(buf, NUM_PAGES * NUM_ENTRIES * getpagesize()); + write_to_memfd(addr1, size, 'b'); + ret = compare_chunks(addr1, addr2, size); + if (ret < 0) { + printf("%s: [FAIL,test-5]\n", TEST_PREFIX); + exit(1); + } + close(buf); + close(memfd); + + /* should work (migration of 2MB size huge pages)*/ + page_size = getpagesize() * 512; /* 2 MB */ + size = MEMFD_SIZE * page_size; + memfd = create_memfd_with_seals(size, true); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); + buf = create_udmabuf_list(devfd, memfd, size); + addr2 = mmap_fd(buf, NUM_PAGES * NUM_ENTRIES * getpagesize()); + write_to_memfd(addr1, size, 'b'); + ret = compare_chunks(addr1, addr2, size); + if (ret < 0) { + printf("%s: [FAIL,test-6]\n", TEST_PREFIX); + exit(1); + } fprintf(stderr, "%s: ok\n", TEST_PREFIX); close(buf);