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From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: David Hildenbrand <david@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, miklos@szeredi.hu, stefanha@redhat.com,
	sweil@redhat.com, swhiteho@redhat.com
Subject: Re: [PATCH 18/52] virtio-fs: Map cache using the values from the capabilities
Date: Thu, 13 Dec 2018 09:13:20 +0000
Message-ID: <20181213091320.GA2313@work-vm> (raw)
In-Reply-To: <de46a955-813b-355d-49f2-4d866603a8fa@redhat.com>

* David Hildenbrand (david@redhat.com) wrote:
> On 10.12.18 18:12, Vivek Goyal wrote:
> > Instead of assuming we had the fixed bar for the cache, use the
> > value from the capabilities.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  fs/fuse/virtio_fs.c | 32 +++++++++++++++++---------------
> >  1 file changed, 17 insertions(+), 15 deletions(-)
> > 
> > diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> > index 60d496c16841..55bac1465536 100644
> > --- a/fs/fuse/virtio_fs.c
> > +++ b/fs/fuse/virtio_fs.c
> > @@ -14,11 +14,6 @@
> >  #include <uapi/linux/virtio_pci.h>
> >  #include "fuse_i.h"
> >  
> > -enum {
> > -	/* PCI BAR number of the virtio-fs DAX window */
> > -	VIRTIO_FS_WINDOW_BAR = 2,
> > -};
> > -
> >  /* List of virtio-fs device instances and a lock for the list */
> >  static DEFINE_MUTEX(virtio_fs_mutex);
> >  static LIST_HEAD(virtio_fs_instances);
> > @@ -518,7 +513,7 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
> >  	struct dev_pagemap *pgmap;
> >  	struct pci_dev *pci_dev;
> >  	phys_addr_t phys_addr;
> > -	size_t len;
> > +	size_t bar_len;
> >  	int ret;
> >  	u8 have_cache, cache_bar;
> >  	u64 cache_offset, cache_len;
> > @@ -551,17 +546,13 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
> >          }
> >  
> >  	/* TODO handle case where device doesn't expose BAR? */
> 
> For virtio-pmem we decided to not go via BARs as this would effectively
> make it only usable for virtio-pci implementers. Instead, we are going
> to export the applicable physical device region directly (e.g.
> phys_start, phys_size in virtio config), so it is decoupled from PCI
> details. Doing the same for virtio-fs would allow e.g. also virtio-ccw
> to make eventually use of this.

That makes it a very odd looking PCI device;  I can see that with
virtio-pmem it makes some sense, given that it's job is to expose
arbitrary chunks of memory.

Dave


> > -	ret = pci_request_region(pci_dev, VIRTIO_FS_WINDOW_BAR,
> > -				 "virtio-fs-window");
> > +	ret = pci_request_region(pci_dev, cache_bar, "virtio-fs-window");
> >  	if (ret < 0) {
> >  		dev_err(&vdev->dev, "%s: failed to request window BAR\n",
> >  			__func__);
> >  		return ret;
> >  	}
> >  
> > -	phys_addr = pci_resource_start(pci_dev, VIRTIO_FS_WINDOW_BAR);
> > -	len = pci_resource_len(pci_dev, VIRTIO_FS_WINDOW_BAR);
> > -
> >  	mi = devm_kzalloc(&pci_dev->dev, sizeof(*mi), GFP_KERNEL);
> >  	if (!mi)
> >  		return -ENOMEM;
> > @@ -586,6 +577,17 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
> >  	pgmap->ref = &mi->ref;
> >  	pgmap->type = MEMORY_DEVICE_FS_DAX;
> >  
> > +	phys_addr = pci_resource_start(pci_dev, cache_bar);
> > +	bar_len = pci_resource_len(pci_dev, cache_bar);
> > +
> > +	if (cache_offset + cache_len > bar_len) {
> > +		dev_err(&vdev->dev,
> > +			"%s: cache bar shorter than cap offset+len\n",
> > +			__func__);
> > +		return -EINVAL;
> > +	}
> > +	phys_addr += cache_offset;
> > +
> >  	/* 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
> > @@ -594,7 +596,7 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
> >  	pgmap->res = (struct resource){
> >  		.name = "virtio-fs dax window",
> >  		.start = phys_addr,
> > -		.end = phys_addr + len,
> > +		.end = phys_addr + cache_len,
> >  	};
> >  
> >  	fs->window_kaddr = devm_memremap_pages(&pci_dev->dev, pgmap);
> > @@ -607,10 +609,10 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
> >  		return ret;
> >  
> >  	fs->window_phys_addr = phys_addr;
> > -	fs->window_len = len;
> > +	fs->window_len = cache_len;
> >  
> > -	dev_dbg(&vdev->dev, "%s: window kaddr 0x%px phys_addr 0x%llx len %zu\n",
> > -		__func__, fs->window_kaddr, phys_addr, len);
> > +	dev_dbg(&vdev->dev, "%s: cache kaddr 0x%px phys_addr 0x%llx len %llx\n",
> > +		__func__, fs->window_kaddr, phys_addr, cache_len);
> >  
> >  	fs->dax_dev = alloc_dax(fs, NULL, &virtio_fs_dax_ops);
> >  	if (!fs->dax_dev)
> > 
> 
> 
> -- 
> 
> Thanks,
> 
> David / dhildenb
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

  reply index

Thread overview: 93+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-10 17:12 [PATCH 00/52] [RFC] virtio-fs: shared file system for virtual machines Vivek Goyal
2018-12-10 17:12 ` [PATCH 01/52] fuse: add skeleton virtio_fs.ko module Vivek Goyal
2018-12-10 17:12 ` [PATCH 02/52] fuse: add probe/remove virtio driver Vivek Goyal
2018-12-10 17:12 ` [PATCH 03/52] fuse: rely on mutex_unlock() barrier instead of fput() Vivek Goyal
2018-12-10 17:12 ` [PATCH 04/52] fuse: extract fuse_fill_super_common() Vivek Goyal
2018-12-10 17:12 ` [PATCH 05/52] virtio_fs: get mount working Vivek Goyal
2018-12-10 17:12 ` [PATCH 06/52] fuse: export fuse_end_request() Vivek Goyal
2018-12-10 17:12 ` [PATCH 07/52] fuse: export fuse_len_args() Vivek Goyal
2018-12-10 17:12 ` [PATCH 08/52] fuse: add fuse_iqueue_ops callbacks Vivek Goyal
2018-12-10 17:12 ` [PATCH 09/52] fuse: process requests queues Vivek Goyal
2018-12-10 17:12 ` [PATCH 10/52] fuse: export fuse_get_unique() Vivek Goyal
2018-12-10 17:12 ` [PATCH 11/52] fuse: implement FUSE_FORGET for virtio-fs Vivek Goyal
2018-12-10 17:12 ` [PATCH 12/52] virtio_fs: Set up dax_device Vivek Goyal
2018-12-10 17:12 ` [PATCH 13/52] dax: remove block device dependencies Vivek Goyal
2018-12-10 17:12 ` [PATCH 14/52] fuse: add fuse_conn->dax_dev field Vivek Goyal
2018-12-10 17:12 ` [PATCH 15/52] fuse: map virtio_fs DAX window BAR Vivek Goyal
2018-12-12 16:37   ` Christian Borntraeger
2018-12-13 11:55     ` Stefan Hajnoczi
2018-12-13 16:06   ` kbuild test robot
2018-12-13 19:55   ` Dan Williams
2018-12-13 20:09     ` Dr. David Alan Gilbert
2018-12-13 20:15       ` Dan Williams
2018-12-13 20:40         ` Vivek Goyal
2018-12-13 21:18           ` Vivek Goyal
2018-12-14 10:09             ` Dr. David Alan Gilbert
2018-12-10 17:12 ` [PATCH 16/52] virtio-fs: Add VIRTIO_PCI_CAP_SHARED_MEMORY_CFG and utility to find them Vivek Goyal
2018-12-12 16:36   ` [PATCH] virtio-fs: fix semicolon.cocci warnings kbuild test robot
2018-12-12 16:36   ` [PATCH 16/52] virtio-fs: Add VIRTIO_PCI_CAP_SHARED_MEMORY_CFG and utility to find them kbuild test robot
2018-12-10 17:12 ` [PATCH 17/52] virtio-fs: Retrieve shm capabilities for cache Vivek Goyal
2018-12-10 17:12 ` [PATCH 18/52] virtio-fs: Map cache using the values from the capabilities Vivek Goyal
2018-12-13  9:10   ` David Hildenbrand
2018-12-13  9:13     ` Dr. David Alan Gilbert [this message]
2018-12-13  9:34       ` David Hildenbrand
2018-12-13 10:00         ` Dr. David Alan Gilbert
2018-12-13 11:26           ` David Hildenbrand
2018-12-13 12:15             ` Dr. David Alan Gilbert
2018-12-13 12:24               ` David Hildenbrand
2018-12-13 12:38                 ` Cornelia Huck
2018-12-14 13:44                   ` Stefan Hajnoczi
2018-12-14 13:50                     ` Cornelia Huck
2018-12-14 14:06                       ` Dr. David Alan Gilbert
2018-12-17 11:25                       ` Stefan Hajnoczi
2018-12-17 10:53                     ` David Hildenbrand
2018-12-17 14:56                       ` Stefan Hajnoczi
2018-12-18 17:13                         ` Cornelia Huck
2018-12-18 17:25                           ` David Hildenbrand
2019-01-02 10:24                             ` Stefan Hajnoczi
2018-12-10 17:12 ` [PATCH 19/52] virito-fs: Make dax optional Vivek Goyal
2018-12-10 17:12 ` [PATCH 20/52] Limit number of pages returned by direct_access() Vivek Goyal
2018-12-10 17:12 ` [PATCH 21/52] fuse: Introduce fuse_dax_mapping Vivek Goyal
2018-12-10 17:12 ` [PATCH 22/52] Create a list of free memory ranges Vivek Goyal
2018-12-11 17:44   ` kbuild test robot
2018-12-15 19:22   ` kbuild test robot
2018-12-10 17:12 ` [PATCH 23/52] fuse: simplify fuse_fill_super_common() calling Vivek Goyal
2018-12-10 17:12 ` [PATCH 24/52] fuse: Introduce setupmapping/removemapping commands Vivek Goyal
2018-12-10 17:12 ` [PATCH 25/52] Introduce interval tree basic data structures Vivek Goyal
2018-12-10 17:12 ` [PATCH 26/52] fuse: Implement basic DAX read/write support commands Vivek Goyal
2018-12-10 17:12 ` [PATCH 27/52] fuse: Maintain a list of busy elements Vivek Goyal
2018-12-10 17:12 ` [PATCH 28/52] Do fallocate() to grow file before mapping for file growing writes Vivek Goyal
2018-12-11  6:13   ` kbuild test robot
2018-12-11  6:20   ` kbuild test robot
2018-12-10 17:12 ` [PATCH 29/52] fuse: add DAX mmap support Vivek Goyal
2018-12-10 17:12 ` [PATCH 30/52] fuse: delete dentry if timeout is zero Vivek Goyal
2018-12-10 17:12 ` [PATCH 31/52] dax: Pass dax_dev to dax_writeback_mapping_range() Vivek Goyal
2018-12-11  6:12   ` kbuild test robot
2018-12-11 17:38   ` kbuild test robot
2018-12-10 17:12 ` [PATCH 32/52] fuse: Define dax address space operations Vivek Goyal
2018-12-10 17:12 ` [PATCH 33/52] fuse, dax: Take ->i_mmap_sem lock during dax page fault Vivek Goyal
2018-12-10 17:13 ` [PATCH 34/52] fuse: Add logic to free up a memory range Vivek Goyal
2018-12-10 17:13 ` [PATCH 35/52] fuse: Add logic to do direct reclaim of memory Vivek Goyal
2018-12-10 17:13 ` [PATCH 36/52] fuse: Kick worker when free memory drops below 20% of total ranges Vivek Goyal
2018-12-10 17:13 ` [PATCH 37/52] fuse: multiplex cached/direct_io/dax file operations Vivek Goyal
2018-12-10 17:13 ` [PATCH 38/52] Dispatch FORGET requests later instead of dropping them Vivek Goyal
2018-12-10 17:13 ` [PATCH 39/52] Release file in process context Vivek Goyal
2018-12-10 17:13 ` [PATCH 40/52] fuse: Do not block on inode lock while freeing memory range Vivek Goyal
2018-12-10 17:13 ` [PATCH 41/52] fuse: Reschedule dax free work if too many EAGAIN attempts Vivek Goyal
2018-12-10 17:13 ` [PATCH 42/52] fuse: Wait for memory ranges to become free Vivek Goyal
2018-12-10 17:13 ` [PATCH 43/52] fuse: Take inode lock for dax inode truncation Vivek Goyal
2018-12-10 17:13 ` [PATCH 44/52] fuse: Clear setuid bit even in direct I/O path Vivek Goyal
2018-12-10 17:13 ` [PATCH 45/52] virtio: Free fuse devices on umount Vivek Goyal
2018-12-10 17:13 ` [PATCH 46/52] virtio-fs: Retrieve shm capabilities for version table Vivek Goyal
2018-12-10 17:13 ` [PATCH 47/52] virtio-fs: Map using the values from the capabilities Vivek Goyal
2018-12-10 17:13 ` [PATCH 48/52] virtio-fs: pass version table pointer to fuse Vivek Goyal
2018-12-10 17:13 ` [PATCH 49/52] fuse: don't crash if version table is NULL Vivek Goyal
2018-12-10 17:13 ` [PATCH 50/52] fuse: add shared version support (virtio-fs only) Vivek Goyal
2018-12-10 17:13 ` [PATCH 51/52] fuse: shared version cleanups Vivek Goyal
2018-12-10 17:13 ` [PATCH 52/52] fuse: fix fuse_permission() for the default_permissions case Vivek Goyal
2018-12-19 21:25   ` kbuild test robot
2018-12-11 12:54 ` [PATCH 00/52] [RFC] virtio-fs: shared file system for virtual machines Stefan Hajnoczi
2018-12-12 20:30 ` Konrad Rzeszutek Wilk
2018-12-12 21:22   ` Vivek Goyal
2019-02-12 15:56 ` Aneesh Kumar K.V
2019-02-12 18:57   ` Vivek Goyal

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