Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

VFIO updates include safer default file flags for VFIO device fds,

Browse source 
an external user interface exported to allow other modules to hold
 references to VFIO groups, a fix to test for extended config space
 on PCIe and PCI-x, and new hot reset interfaces for PCI devices
 which allows the user to do PCI bus/slot resets when all of the
 devices affected by the reset are owned by the user.
 
 For this last feature, the PCI bus reset interface, I depend on
 changes already merged from Bjorn's PCI pull request.  I therefore
 merged my tree up to commit cb3e433, which I think was the correct
 action, but as Stephen Rothwell noted, I failed to provide a commit
 message indicating why the merge was required.  Sorry for that.
 Thanks,
 Alex
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.13 (GNU/Linux)
 
 iQIcBAABAgAGBQJSLKr0AAoJECObm247sIsiouMP/1rym/JDjSsjIONvjnQEH5hk
 aZy3gGjqvSBBSN2aWqYkEgsSmgh4lSdDAbSBpY6vfz4Q0h7OXhSZcZ5oG2eGECia
 rN6GvfI/g2mYBCHJbS30bEkpljx9ssMZi7n9dnWOWEkzXSTC/uLHx9DCUiHdczPF
 SEeEHbxAnCTL5S5SQgUwhjPI813eVPjm94KDZK6pHcd14GGtM/piGjJNkyfzymRZ
 0l7lu95YaY70qL1Bk1EZ2TlsqWtYeKfDXsp465U3uBj5eXslMKpxXBn/XndRWu25
 ZnjRitF/izMZdcBgIM4uVK/yDhdAI2qav1rtkVirqp9Qrs9BgJXxUpO3p0e/GhFl
 KZgq3DnE1aUfJlyu+YGmjIKWDT+CBrkkxidRwYoaBCs3if/1E19zUH5Gfuuimy/D
 rpET3HPuJlPhxyE2vH9u6EVTybBx4wlvDP43FyhetriQjwv+SuPP2oNWD96L/qBY
 BHcSMHfkyq90Lp6tjCeTISkwOb66qqkRUlzycPiB67BgrIea8yn14lKpE7GLcgmO
 XSLLRvv6tFD2VcqEWQZNLoLo8XqAngvgStbOXxiTFpSQD4h2Z0TbpSc9qdVZlgIt
 JBMA0BuDj+gzCDePUlsuM5L1EVOaFuKSHiZA6MUewDBqiiKoWPPsDKsFpKt2jFv4
 Mp47JcWkDBg1DCC8nQ7f
 =FAuJ
 -----END PGP SIGNATURE-----

Merge tag 'vfio-v3.12-rc0' of git://github.com/awilliam/linux-vfio

Pull VFIO update from Alex Williamson:
 "VFIO updates include safer default file flags for VFIO device fds, an
  external user interface exported to allow other modules to hold
  references to VFIO groups, a fix to test for extended config space on
  PCIe and PCI-x, and new hot reset interfaces for PCI devices which
  allows the user to do PCI bus/slot resets when all of the devices
  affected by the reset are owned by the user.

  For this last feature, the PCI bus reset interface, I depend on
  changes already merged from Bjorn's PCI pull request.  I therefore
  merged my tree up to commit cb3e433, which I think was the correct
  action, but as Stephen Rothwell noted, I failed to provide a commit
  message indicating why the merge was required.  Sorry for that.
  Thanks, Alex"

* tag 'vfio-v3.12-rc0' of git://github.com/awilliam/linux-vfio:
  vfio: fix documentation
  vfio-pci: PCI hot reset interface
  vfio-pci: Test for extended config space
  vfio-pci: Use fdget() rather than eventfd_fget()
  vfio: Add O_CLOEXEC flag to vfio device fd
  vfio: use get_unused_fd_flags(0) instead of get_unused_fd()
  vfio: add external user support
This commit is contained in:
Linus Torvalds 2013-09-09 10:19:36 -07:00
commit d75671e36e
7 changed files with 421 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
Documentation/vfio.txt
View file

@ -167,8 +167,8 @@ group and can access them as follows:
int container, group, device, i;
struct vfio_group_status group_status =
{ .argsz = sizeof(group_status) };
struct vfio_iommu_x86_info iommu_info = { .argsz = sizeof(iommu_info) };
struct vfio_iommu_x86_dma_map dma_map = { .argsz = sizeof(dma_map) };
struct vfio_iommu_type1_info iommu_info = { .argsz = sizeof(iommu_info) };
struct vfio_iommu_type1_dma_map dma_map = { .argsz = sizeof(dma_map) };
struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
/* Create a new container */
@ -193,7 +193,7 @@ group and can access them as follows:
ioctl(group, VFIO_GROUP_SET_CONTAINER, &container);
/* Enable the IOMMU model we want */
ioctl(container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU)
ioctl(container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
/* Get addition IOMMU info */
ioctl(container, VFIO_IOMMU_GET_INFO, &iommu_info);
@ -229,7 +229,7 @@ group and can access them as follows:
irq.index = i;
ioctl(device, VFIO_DEVICE_GET_IRQ_INFO, &reg);
ioctl(device, VFIO_DEVICE_GET_IRQ_INFO, &irq);
/* Setup IRQs... eventfds, VFIO_DEVICE_SET_IRQS */
}

286
drivers/vfio/pci/vfio_pci.c
View file

@ -13,6 +13,7 @@
#include <linux/device.h>
#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/interrupt.h>
#include <linux/iommu.h>
#include <linux/module.h>
@ -227,6 +228,110 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
return 0;
}
static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
{
(*(int *)data)++;
return 0;
}
struct vfio_pci_fill_info {
int max;
int cur;
struct vfio_pci_dependent_device *devices;
};
static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
{
struct vfio_pci_fill_info *fill = data;
struct iommu_group *iommu_group;
if (fill->cur == fill->max)
return -EAGAIN; /* Something changed, try again */
iommu_group = iommu_group_get(&pdev->dev);
if (!iommu_group)
return -EPERM; /* Cannot reset non-isolated devices */
fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
fill->devices[fill->cur].bus = pdev->bus->number;
fill->devices[fill->cur].devfn = pdev->devfn;
fill->cur++;
iommu_group_put(iommu_group);
return 0;
}
struct vfio_pci_group_entry {
struct vfio_group *group;
int id;
};
struct vfio_pci_group_info {
int count;
struct vfio_pci_group_entry *groups;
};
static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
{
struct vfio_pci_group_info *info = data;
struct iommu_group *group;
int id, i;
group = iommu_group_get(&pdev->dev);
if (!group)
return -EPERM;
id = iommu_group_id(group);
for (i = 0; i < info->count; i++)
if (info->groups[i].id == id)
break;
iommu_group_put(group);
return (i == info->count) ? -EINVAL : 0;
}
static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
{
for (; pdev; pdev = pdev->bus->self)
if (pdev->bus == slot->bus)
return (pdev->slot == slot);
return false;
}
struct vfio_pci_walk_info {
int (*fn)(struct pci_dev *, void *data);
void *data;
struct pci_dev *pdev;
bool slot;
int ret;
};
static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
{
struct vfio_pci_walk_info *walk = data;
if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
walk->ret = walk->fn(pdev, walk->data);
return walk->ret;
}
static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
int (*fn)(struct pci_dev *,
void *data), void *data,
bool slot)
{
struct vfio_pci_walk_info walk = {
.fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
};
pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
return walk.ret;
}
static long vfio_pci_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
@ -407,10 +512,189 @@ static long vfio_pci_ioctl(void *device_data,
return ret;
} else if (cmd == VFIO_DEVICE_RESET)
} else if (cmd == VFIO_DEVICE_RESET) {
return vdev->reset_works ?
pci_reset_function(vdev->pdev) : -EINVAL;
} else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
struct vfio_pci_hot_reset_info hdr;
struct vfio_pci_fill_info fill = { 0 };
struct vfio_pci_dependent_device *devices = NULL;
bool slot = false;
int ret = 0;
minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
if (hdr.argsz < minsz)
return -EINVAL;
hdr.flags = 0;
/* Can we do a slot or bus reset or neither? */
if (!pci_probe_reset_slot(vdev->pdev->slot))
slot = true;
else if (pci_probe_reset_bus(vdev->pdev->bus))
return -ENODEV;
/* How many devices are affected? */
ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
vfio_pci_count_devs,
&fill.max, slot);
if (ret)
return ret;
WARN_ON(!fill.max); /* Should always be at least one */
/*
* If there's enough space, fill it now, otherwise return
* -ENOSPC and the number of devices affected.
*/
if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
ret = -ENOSPC;
hdr.count = fill.max;
goto reset_info_exit;
}
devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
if (!devices)
return -ENOMEM;
fill.devices = devices;
ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
vfio_pci_fill_devs,
&fill, slot);
/*
* If a device was removed between counting and filling,
* we may come up short of fill.max. If a device was
* added, we'll have a return of -EAGAIN above.
*/
if (!ret)
hdr.count = fill.cur;
reset_info_exit:
if (copy_to_user((void __user *)arg, &hdr, minsz))
ret = -EFAULT;
if (!ret) {
if (copy_to_user((void __user *)(arg + minsz), devices,
hdr.count * sizeof(*devices)))
ret = -EFAULT;
}
kfree(devices);
return ret;
} else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
struct vfio_pci_hot_reset hdr;
int32_t *group_fds;
struct vfio_pci_group_entry *groups;
struct vfio_pci_group_info info;
bool slot = false;
int i, count = 0, ret = 0;
minsz = offsetofend(struct vfio_pci_hot_reset, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
if (hdr.argsz < minsz || hdr.flags)
return -EINVAL;
/* Can we do a slot or bus reset or neither? */
if (!pci_probe_reset_slot(vdev->pdev->slot))
slot = true;
else if (pci_probe_reset_bus(vdev->pdev->bus))
return -ENODEV;
/*
* We can't let userspace give us an arbitrarily large
* buffer to copy, so verify how many we think there
* could be. Note groups can have multiple devices so
* one group per device is the max.
*/
ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
vfio_pci_count_devs,
&count, slot);
if (ret)
return ret;
/* Somewhere between 1 and count is OK */
if (!hdr.count || hdr.count > count)
return -EINVAL;
group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
if (!group_fds || !groups) {
kfree(group_fds);
kfree(groups);
return -ENOMEM;
}
if (copy_from_user(group_fds, (void __user *)(arg + minsz),
hdr.count * sizeof(*group_fds))) {
kfree(group_fds);
kfree(groups);
return -EFAULT;
}
/*
* For each group_fd, get the group through the vfio external
* user interface and store the group and iommu ID. This
* ensures the group is held across the reset.
*/
for (i = 0; i < hdr.count; i++) {
struct vfio_group *group;
struct fd f = fdget(group_fds[i]);
if (!f.file) {
ret = -EBADF;
break;
}
group = vfio_group_get_external_user(f.file);
fdput(f);
if (IS_ERR(group)) {
ret = PTR_ERR(group);
break;
}
groups[i].group = group;
groups[i].id = vfio_external_user_iommu_id(group);
}
kfree(group_fds);
/* release reference to groups on error */
if (ret)
goto hot_reset_release;
info.count = hdr.count;
info.groups = groups;
/*
* Test whether all the affected devices are contained
* by the set of groups provided by the user.
*/
ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
vfio_pci_validate_devs,
&info, slot);
if (!ret)
/* User has access, do the reset */
ret = slot ? pci_reset_slot(vdev->pdev->slot) :
pci_reset_bus(vdev->pdev->bus);
hot_reset_release:
for (i--; i >= 0; i--)
vfio_group_put_external_user(groups[i].group);
kfree(groups);
return ret;
}
return -ENOTTY;
}

11
drivers/vfio/pci/vfio_pci_config.c
View file

@ -1012,6 +1012,7 @@ static int vfio_vc_cap_len(struct vfio_pci_device *vdev, u16 pos)
static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
{
struct pci_dev *pdev = vdev->pdev;
u32 dword;
u16 word;
u8 byte;
int ret;
@ -1025,7 +1026,9 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
return pcibios_err_to_errno(ret);
if (PCI_X_CMD_VERSION(word)) {
vdev->extended_caps = true;
/* Test for extended capabilities */
pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword);
vdev->extended_caps = (dword != 0);
return PCI_CAP_PCIX_SIZEOF_V2;
} else
return PCI_CAP_PCIX_SIZEOF_V0;
@ -1037,9 +1040,11 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
return byte;
case PCI_CAP_ID_EXP:
/* length based on version */
vdev->extended_caps = true;
/* Test for extended capabilities */
pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword);
vdev->extended_caps = (dword != 0);
/* length based on version */
if ((pcie_caps_reg(pdev) & PCI_EXP_FLAGS_VERS) == 1)
return PCI_CAP_EXP_ENDPOINT_SIZEOF_V1;
else

35
drivers/vfio/pci/vfio_pci_intrs.c
View file

@ -130,8 +130,8 @@ static int virqfd_enable(struct vfio_pci_device *vdev,
void (*thread)(struct vfio_pci_device *, void *),
void *data, struct virqfd **pvirqfd, int fd)
{
struct file *file = NULL;
struct eventfd_ctx *ctx = NULL;
struct fd irqfd;
struct eventfd_ctx *ctx;
struct virqfd *virqfd;
int ret = 0;
unsigned int events;
@ -149,16 +149,16 @@ static int virqfd_enable(struct vfio_pci_device *vdev,
INIT_WORK(&virqfd->shutdown, virqfd_shutdown);
INIT_WORK(&virqfd->inject, virqfd_inject);
file = eventfd_fget(fd);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto fail;
irqfd = fdget(fd);
if (!irqfd.file) {
ret = -EBADF;
goto err_fd;
}
ctx = eventfd_ctx_fileget(file);
ctx = eventfd_ctx_fileget(irqfd.file);
if (IS_ERR(ctx)) {
ret = PTR_ERR(ctx);
goto fail;
goto err_ctx;
}
virqfd->eventfd = ctx;
@ -174,7 +174,7 @@ static int virqfd_enable(struct vfio_pci_device *vdev,
if (*pvirqfd) {
spin_unlock_irq(&vdev->irqlock);
ret = -EBUSY;
goto fail;
goto err_busy;
}
*pvirqfd = virqfd;
@ -187,7 +187,7 @@ static int virqfd_enable(struct vfio_pci_device *vdev,
init_waitqueue_func_entry(&virqfd->wait, virqfd_wakeup);
init_poll_funcptr(&virqfd->pt, virqfd_ptable_queue_proc);
events = file->f_op->poll(file, &virqfd->pt);
events = irqfd.file->f_op->poll(irqfd.file, &virqfd->pt);
/*
* Check if there was an event already pending on the eventfd
@ -202,17 +202,14 @@ static int virqfd_enable(struct vfio_pci_device *vdev,
* Do not drop the file until the irqfd is fully initialized,
* otherwise we might race against the POLLHUP.
*/
fput(file);
fdput(irqfd);
return 0;
fail:
if (ctx && !IS_ERR(ctx))
eventfd_ctx_put(ctx);
if (file && !IS_ERR(file))
fput(file);
err_busy:
eventfd_ctx_put(ctx);
err_ctx:
fdput(irqfd);
err_fd:
kfree(virqfd);
return ret;

64
drivers/vfio/vfio.c
View file

@ -1109,7 +1109,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
* We can't use anon_inode_getfd() because we need to modify
* the f_mode flags directly to allow more than just ioctls
*/
ret = get_unused_fd();
ret = get_unused_fd_flags(O_CLOEXEC);
if (ret < 0) {
device->ops->release(device->device_data);
break;
@ -1352,6 +1352,68 @@ static const struct file_operations vfio_device_fops = {
.mmap = vfio_device_fops_mmap,
};
/**
* External user API, exported by symbols to be linked dynamically.
*
* The protocol includes:
* 1. do normal VFIO init operation:
* - opening a new container;
* - attaching group(s) to it;
* - setting an IOMMU driver for a container.
* When IOMMU is set for a container, all groups in it are
* considered ready to use by an external user.
*
* 2. User space passes a group fd to an external user.
* The external user calls vfio_group_get_external_user()
* to verify that:
* - the group is initialized;
* - IOMMU is set for it.
* If both checks passed, vfio_group_get_external_user()
* increments the container user counter to prevent
* the VFIO group from disposal before KVM exits.
*
* 3. The external user calls vfio_external_user_iommu_id()
* to know an IOMMU ID.
*
* 4. When the external KVM finishes, it calls
* vfio_group_put_external_user() to release the VFIO group.
* This call decrements the container user counter.
*/
struct vfio_group *vfio_group_get_external_user(struct file *filep)
{
struct vfio_group *group = filep->private_data;
if (filep->f_op != &vfio_group_fops)
return ERR_PTR(-EINVAL);
if (!atomic_inc_not_zero(&group->container_users))
return ERR_PTR(-EINVAL);
if (!group->container->iommu_driver ||
!vfio_group_viable(group)) {
atomic_dec(&group->container_users);
return ERR_PTR(-EINVAL);
}
vfio_group_get(group);
return group;
}
EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
void vfio_group_put_external_user(struct vfio_group *group)
{
vfio_group_put(group);
vfio_group_try_dissolve_container(group);
}
EXPORT_SYMBOL_GPL(vfio_group_put_external_user);
int vfio_external_user_iommu_id(struct vfio_group *group)
{
return iommu_group_id(group->iommu_group);
}
EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
/**
* Module/class support
*/

7
include/linux/vfio.h
View file

@ -90,4 +90,11 @@ extern void vfio_unregister_iommu_driver(
TYPE tmp; \
offsetof(TYPE, MEMBER) + sizeof(tmp.MEMBER); }) \
/*
* External user API
*/
extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
extern void vfio_group_put_external_user(struct vfio_group *group);
extern int vfio_external_user_iommu_id(struct vfio_group *group);
#endif /* VFIO_H */

38
include/uapi/linux/vfio.h
View file

@ -324,6 +324,44 @@ enum {
VFIO_PCI_NUM_IRQS
};
/**
* VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IORW(VFIO_TYPE, VFIO_BASE + 12,
* struct vfio_pci_hot_reset_info)
*
* Return: 0 on success, -errno on failure:
* -enospc = insufficient buffer, -enodev = unsupported for device.
*/
struct vfio_pci_dependent_device {
__u32 group_id;
__u16 segment;
__u8 bus;
__u8 devfn; /* Use PCI_SLOT/PCI_FUNC */
};
struct vfio_pci_hot_reset_info {
__u32 argsz;
__u32 flags;
__u32 count;
struct vfio_pci_dependent_device devices[];
};
#define VFIO_DEVICE_GET_PCI_HOT_RESET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
/**
* VFIO_DEVICE_PCI_HOT_RESET - _IOW(VFIO_TYPE, VFIO_BASE + 13,
* struct vfio_pci_hot_reset)
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_pci_hot_reset {
__u32 argsz;
__u32 flags;
__u32 count;
__s32 group_fds[];
};
#define VFIO_DEVICE_PCI_HOT_RESET _IO(VFIO_TYPE, VFIO_BASE + 13)
/* -------- API for Type1 VFIO IOMMU -------- */
/**