From: Alex Williamson <alex.williamson@redhat.com>
To: alex.williamson@redhat.com
Cc: cohuck@redhat.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, jgg@nvidia.com, peterx@redhat.com
Subject: [PATCH v1 01/14] vfio: Create vfio_fs_type with inode per device
Date: Mon, 08 Mar 2021 14:47:28 -0700 [thread overview]
Message-ID: <161524004828.3480.1817334832614722574.stgit@gimli.home> (raw)
In-Reply-To: <161523878883.3480.12103845207889888280.stgit@gimli.home>
By linking all the device fds we provide to userspace to an
address space through a new pseudo fs, we can use tools like
unmap_mapping_range() to zap all vmas associated with a device.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
drivers/vfio/vfio.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 38779e6fd80c..abdf8d52a911 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -32,11 +32,18 @@
#include <linux/vfio.h>
#include <linux/wait.h>
#include <linux/sched/signal.h>
+#include <linux/pseudo_fs.h>
+#include <linux/mount.h>
#define DRIVER_VERSION "0.3"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
#define DRIVER_DESC "VFIO - User Level meta-driver"
+#define VFIO_MAGIC 0x5646494f /* "VFIO" */
+
+static int vfio_fs_cnt;
+static struct vfsmount *vfio_fs_mnt;
+
static struct vfio {
struct class *class;
struct list_head iommu_drivers_list;
@@ -97,6 +104,7 @@ struct vfio_device {
struct vfio_group *group;
struct list_head group_next;
void *device_data;
+ struct inode *inode;
};
#ifdef CONFIG_VFIO_NOIOMMU
@@ -529,6 +537,34 @@ static struct vfio_group *vfio_group_get_from_dev(struct device *dev)
return group;
}
+static int vfio_fs_init_fs_context(struct fs_context *fc)
+{
+ return init_pseudo(fc, VFIO_MAGIC) ? 0 : -ENOMEM;
+}
+
+static struct file_system_type vfio_fs_type = {
+ .name = "vfio",
+ .owner = THIS_MODULE,
+ .init_fs_context = vfio_fs_init_fs_context,
+ .kill_sb = kill_anon_super,
+};
+
+static struct inode *vfio_fs_inode_new(void)
+{
+ struct inode *inode;
+ int ret;
+
+ ret = simple_pin_fs(&vfio_fs_type, &vfio_fs_mnt, &vfio_fs_cnt);
+ if (ret)
+ return ERR_PTR(ret);
+
+ inode = alloc_anon_inode(vfio_fs_mnt->mnt_sb);
+ if (IS_ERR(inode))
+ simple_release_fs(&vfio_fs_mnt, &vfio_fs_cnt);
+
+ return inode;
+}
+
/**
* Device objects - create, release, get, put, search
*/
@@ -539,11 +575,19 @@ struct vfio_device *vfio_group_create_device(struct vfio_group *group,
void *device_data)
{
struct vfio_device *device;
+ struct inode *inode;
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (!device)
return ERR_PTR(-ENOMEM);
+ inode = vfio_fs_inode_new();
+ if (IS_ERR(inode)) {
+ kfree(device);
+ return ERR_CAST(inode);
+ }
+ device->inode = inode;
+
kref_init(&device->kref);
device->dev = dev;
device->group = group;
@@ -574,6 +618,9 @@ static void vfio_device_release(struct kref *kref)
dev_set_drvdata(device->dev, NULL);
+ iput(device->inode);
+ simple_release_fs(&vfio_fs_mnt, &vfio_fs_cnt);
+
kfree(device);
/* vfio_del_group_dev may be waiting for this device */
@@ -1488,6 +1535,13 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
*/
filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
+ /*
+ * Use the pseudo fs inode on the device to link all mmaps
+ * to the same address space, allowing us to unmap all vmas
+ * associated to this device using unmap_mapping_range().
+ */
+ filep->f_mapping = device->inode->i_mapping;
+
atomic_inc(&group->container_users);
fd_install(ret, filep);
next prev parent reply other threads:[~2021-03-08 21:48 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-08 21:47 [PATCH v1 00/14] vfio: Device memory DMA mapping improvements Alex Williamson
2021-03-08 21:47 ` Alex Williamson [this message]
2021-03-09 8:36 ` [PATCH v1 01/14] vfio: Create vfio_fs_type with inode per device Christoph Hellwig
2021-04-09 4:54 ` 答复: " Zengtao (B)
2021-04-09 14:24 ` Alex Williamson
2021-04-09 17:32 ` Jason Gunthorpe
2021-04-12 4:03 ` 答复: " Zengtao (B)
2021-04-12 4:09 ` Zengtao (B)
2021-03-08 21:47 ` [PATCH v1 02/14] vfio: Update vfio_add_group_dev() API Alex Williamson
2021-03-10 7:48 ` Christoph Hellwig
2021-03-10 12:19 ` Jason Gunthorpe
2021-03-10 15:28 ` Alex Williamson
2021-03-11 11:23 ` Christoph Hellwig
2021-03-08 21:47 ` [PATCH v1 03/14] vfio: Export unmap_mapping_range() wrapper Alex Williamson
2021-03-08 21:48 ` [PATCH v1 04/14] vfio/pci: Use vfio_device_unmap_mapping_range() Alex Williamson
2021-03-08 21:48 ` [PATCH v1 05/14] vfio: Create a vfio_device from vma lookup Alex Williamson
2021-03-08 21:48 ` [PATCH v1 06/14] vfio: Add vma to pfn callback Alex Williamson
2021-03-09 0:33 ` Jason Gunthorpe
2021-03-08 21:48 ` [PATCH v1 07/14] vfio: Add a device notifier interface Alex Williamson
2021-03-09 0:46 ` Jason Gunthorpe
2021-03-09 15:45 ` Alex Williamson
2021-03-09 16:47 ` Jason Gunthorpe
2021-03-10 7:56 ` Christoph Hellwig
2021-03-19 22:25 ` Alex Williamson
2021-03-22 15:16 ` Christoph Hellwig
2021-03-08 21:48 ` [PATCH v1 08/14] vfio/pci: Notify on device release Alex Williamson
2021-03-08 21:48 ` [PATCH v1 09/14] vfio/type1: Refactor pfn_list clearing Alex Williamson
2021-03-10 8:01 ` Christoph Hellwig
2021-03-08 21:49 ` [PATCH v1 10/14] vfio/type1: Pass iommu and dma objects through to vaddr_get_pfn Alex Williamson
2021-03-08 21:49 ` [PATCH v1 11/14] vfio/type1: Register device notifier Alex Williamson
2021-03-10 8:03 ` Christoph Hellwig
2021-03-08 21:49 ` [PATCH v1 12/14] vfio/type1: Support batching of device mappings Alex Williamson
2021-03-09 1:04 ` Jason Gunthorpe
2021-03-08 21:49 ` [PATCH v1 13/14] vfio: Remove extern from declarations across vfio Alex Williamson
2021-03-09 0:21 ` Halil Pasic
2021-03-09 1:07 ` Jason Gunthorpe
2021-03-08 21:49 ` [PATCH v1 14/14] vfio: Cleanup use of bare unsigned Alex Williamson
2021-03-09 1:07 ` Jason Gunthorpe
2021-03-09 8:31 ` Christoph Hellwig
2021-03-09 1:06 ` [PATCH v1 00/14] vfio: Device memory DMA mapping improvements Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=161524004828.3480.1817334832614722574.stgit@gimli.home \
--to=alex.williamson@redhat.com \
--cc=cohuck@redhat.com \
--cc=jgg@nvidia.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterx@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).