diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-09 17:19:36 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-09 17:19:36 (GMT) |
commit | d75671e36e14b73d7c0d3cec49328dcd984af699 (patch) | |
tree | 87604fe7c082b82b436f2111e47f5a366436271e | |
parent | bf97293eb878df3792d9de7213bd7b82135aea77 (diff) | |
parent | dac09b57c0ff57e55dd6fa5109076c8af0468a75 (diff) | |
download | linux-fsl-qoriq-d75671e36e14b73d7c0d3cec49328dcd984af699.tar.xz |
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
-rw-r--r-- | Documentation/vfio.txt | 8 | ||||
-rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 286 | ||||
-rw-r--r-- | drivers/vfio/pci/vfio_pci_config.c | 11 | ||||
-rw-r--r-- | drivers/vfio/pci/vfio_pci_intrs.c | 35 | ||||
-rw-r--r-- | drivers/vfio/vfio.c | 64 | ||||
-rw-r--r-- | include/linux/vfio.h | 7 | ||||
-rw-r--r-- | include/uapi/linux/vfio.h | 38 |
7 files changed, 421 insertions, 28 deletions
diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt index d7993dc..b9ca023 100644 --- a/Documentation/vfio.txt +++ b/Documentation/vfio.txt @@ -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, ®); + ioctl(device, VFIO_DEVICE_GET_IRQ_INFO, &irq); /* Setup IRQs... eventfds, VFIO_DEVICE_SET_IRQS */ } diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index cef6002..6ab71b9 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -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; } diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index affa347..ffd0632 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -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 diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 4bc704e..641bc87 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -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; diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 842f450..1eab4ac 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -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; @@ -1353,6 +1353,68 @@ static const struct file_operations vfio_device_fops = { }; /** + * 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 */ static char *vfio_devnode(struct device *dev, umode_t *mode) diff --git a/include/linux/vfio.h b/include/linux/vfio.h index ac8d488..24579a0 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -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 */ diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 916e444..0fd47f5 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -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 -------- */ /** |