From patchwork Wed Aug 19 22:19:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11725133 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 74B70138C for ; Wed, 19 Aug 2020 22:22:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5865320FC3 for ; Wed, 19 Aug 2020 22:22:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HHzxo9it" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727070AbgHSWV5 (ORCPT ); Wed, 19 Aug 2020 18:21:57 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:24042 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727901AbgHSWVM (ORCPT ); Wed, 19 Aug 2020 18:21:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597875670; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YNzImEKffgBBrRILbRqWkPn7W48F7RsVK64WzriJRtY=; b=HHzxo9itGVP+02LblQlBP7FegrItxWyld7WZ42vIfABZlngVOLYECddTXm7uHF9yzWlGUB IOfp0EZ21elCeb2cHHvAEWKszsAQKy5svgitxFLmcIyHL1wbwtot23VSYAuU15wdDhleRB qOT3miU/Gx43gIPfwEZfWI0Op3SlJRY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-439-G1v28SMvPaOjwJ9ww0lUIA-1; Wed, 19 Aug 2020 18:21:06 -0400 X-MC-Unique: G1v28SMvPaOjwJ9ww0lUIA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1C7DF1007472; Wed, 19 Aug 2020 22:21:04 +0000 (UTC) Received: from horse.redhat.com (ovpn-115-197.rdu2.redhat.com [10.10.115.197]) by smtp.corp.redhat.com (Postfix) with ESMTP id 66F0B756C8; Wed, 19 Aug 2020 22:21:01 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id F143C2256E6; Wed, 19 Aug 2020 18:20:53 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, virtio-fs@redhat.com Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, dan.j.williams@intel.com, Sebastien Boeuf , Liu Bo Subject: [PATCH v3 08/18] virtio_fs, dax: Set up virtio_fs dax_device Date: Wed, 19 Aug 2020 18:19:46 -0400 Message-Id: <20200819221956.845195-9-vgoyal@redhat.com> In-Reply-To: <20200819221956.845195-1-vgoyal@redhat.com> References: <20200819221956.845195-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Stefan Hajnoczi Setup a dax device. Use the shm capability to find the cache entry and map it. The DAX window is accessed by the fs/dax.c infrastructure and must have struct pages (at least on x86). Use devm_memremap_pages() to map the DAX window PCI BAR and allocate struct page. Signed-off-by: Stefan Hajnoczi Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Vivek Goyal Signed-off-by: Sebastien Boeuf Signed-off-by: Liu Bo --- fs/fuse/virtio_fs.c | 139 +++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_fs.h | 3 + 2 files changed, 142 insertions(+) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 47ecdc15f25d..0fd3b5cecc5f 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -5,12 +5,16 @@ */ #include +#include +#include +#include #include #include #include #include #include #include +#include #include "fuse_i.h" /* List of virtio-fs device instances and a lock for the list. Also provides @@ -49,6 +53,12 @@ struct virtio_fs { struct virtio_fs_vq *vqs; unsigned int nvqs; /* number of virtqueues */ unsigned int num_request_queues; /* number of request queues */ + struct dax_device *dax_dev; + + /* DAX memory window where file contents are mapped */ + void *window_kaddr; + phys_addr_t window_phys_addr; + size_t window_len; }; struct virtio_fs_forget_req { @@ -686,6 +696,131 @@ static void virtio_fs_cleanup_vqs(struct virtio_device *vdev, vdev->config->del_vqs(vdev); } +/* Map a window offset to a page frame number. The window offset will have + * been produced by .iomap_begin(), which maps a file offset to a window + * offset. + */ +static long virtio_fs_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, + long nr_pages, void **kaddr, pfn_t *pfn) +{ + struct virtio_fs *fs = dax_get_private(dax_dev); + phys_addr_t offset = PFN_PHYS(pgoff); + size_t max_nr_pages = fs->window_len/PAGE_SIZE - pgoff; + + if (kaddr) + *kaddr = fs->window_kaddr + offset; + if (pfn) + *pfn = phys_to_pfn_t(fs->window_phys_addr + offset, + PFN_DEV | PFN_MAP); + return nr_pages > max_nr_pages ? max_nr_pages : nr_pages; +} + +static size_t virtio_fs_copy_from_iter(struct dax_device *dax_dev, + pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i) +{ + return copy_from_iter(addr, bytes, i); +} + +static size_t virtio_fs_copy_to_iter(struct dax_device *dax_dev, + pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i) +{ + return copy_to_iter(addr, bytes, i); +} + +static int virtio_fs_zero_page_range(struct dax_device *dax_dev, + pgoff_t pgoff, size_t nr_pages) +{ + long rc; + void *kaddr; + + rc = dax_direct_access(dax_dev, pgoff, nr_pages, &kaddr, NULL); + if (rc < 0) + return rc; + memset(kaddr, 0, nr_pages << PAGE_SHIFT); + dax_flush(dax_dev, kaddr, nr_pages << PAGE_SHIFT); + return 0; +} + +static const struct dax_operations virtio_fs_dax_ops = { + .direct_access = virtio_fs_direct_access, + .copy_from_iter = virtio_fs_copy_from_iter, + .copy_to_iter = virtio_fs_copy_to_iter, + .zero_page_range = virtio_fs_zero_page_range, +}; + +static void virtio_fs_cleanup_dax(void *data) +{ + struct dax_device *dax_dev = data; + + kill_dax(dax_dev); + put_dax(dax_dev); +} + +static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs) +{ + struct virtio_shm_region cache_reg; + struct dev_pagemap *pgmap; + bool have_cache; + + if (!IS_ENABLED(CONFIG_DAX_DRIVER)) + return 0; + + /* Get cache region */ + have_cache = virtio_get_shm_region(vdev, &cache_reg, + (u8)VIRTIO_FS_SHMCAP_ID_CACHE); + if (!have_cache) { + dev_notice(&vdev->dev, "%s: No cache capability\n", __func__); + return 0; + } + + if (!devm_request_mem_region(&vdev->dev, cache_reg.addr, cache_reg.len, + dev_name(&vdev->dev))) { + dev_warn(&vdev->dev, "could not reserve region addr=0x%llx" + " len=0x%llx\n", cache_reg.addr, cache_reg.len); + return -EBUSY; + } + + dev_notice(&vdev->dev, "Cache len: 0x%llx @ 0x%llx\n", cache_reg.len, + cache_reg.addr); + + pgmap = devm_kzalloc(&vdev->dev, sizeof(*pgmap), GFP_KERNEL); + if (!pgmap) + return -ENOMEM; + + pgmap->type = MEMORY_DEVICE_FS_DAX; + + /* Ideally we would directly use the PCI BAR resource but + * devm_memremap_pages() wants its own copy in pgmap. So + * initialize a struct resource from scratch (only the start + * and end fields will be used). + */ + pgmap->res = (struct resource){ + .name = "virtio-fs dax window", + .start = (phys_addr_t) cache_reg.addr, + .end = (phys_addr_t) cache_reg.addr + cache_reg.len - 1, + }; + + fs->window_kaddr = devm_memremap_pages(&vdev->dev, pgmap); + if (IS_ERR(fs->window_kaddr)) + return PTR_ERR(fs->window_kaddr); + + fs->window_phys_addr = (phys_addr_t) cache_reg.addr; + fs->window_len = (phys_addr_t) cache_reg.len; + + dev_dbg(&vdev->dev, "%s: window kaddr 0x%px phys_addr 0x%llx" + " len 0x%llx\n", __func__, fs->window_kaddr, cache_reg.addr, + cache_reg.len); + + fs->dax_dev = alloc_dax(fs, NULL, &virtio_fs_dax_ops, 0); + if (IS_ERR(fs->dax_dev)) + return PTR_ERR(fs->dax_dev); + + return devm_add_action_or_reset(&vdev->dev, virtio_fs_cleanup_dax, + fs->dax_dev); +} + static int virtio_fs_probe(struct virtio_device *vdev) { struct virtio_fs *fs; @@ -707,6 +842,10 @@ static int virtio_fs_probe(struct virtio_device *vdev) /* TODO vq affinity */ + ret = virtio_fs_setup_dax(vdev, fs); + if (ret < 0) + goto out_vqs; + /* Bring the device online in case the filesystem is mounted and * requests need to be sent before we return. */ diff --git a/include/uapi/linux/virtio_fs.h b/include/uapi/linux/virtio_fs.h index 3056b6e9f8ce..bea38291421b 100644 --- a/include/uapi/linux/virtio_fs.h +++ b/include/uapi/linux/virtio_fs.h @@ -16,4 +16,7 @@ struct virtio_fs_config { __le32 num_request_queues; } __attribute__((packed)); +/* For the id field in virtio_pci_shm_cap */ +#define VIRTIO_FS_SHMCAP_ID_CACHE 0 + #endif /* _UAPI_LINUX_VIRTIO_FS_H */