return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
}
- } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
+ } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
if (pci_is_pcie(vdev->pdev))
return 1;
+ } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
+ return 1;
+ }
return 0;
}
switch (info.index) {
case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
+ case VFIO_PCI_REQ_IRQ_INDEX:
break;
case VFIO_PCI_ERR_IRQ_INDEX:
if (pci_is_pcie(vdev->pdev))
req_len, vma->vm_page_prot);
}
+static void vfio_pci_request(void *device_data, unsigned int count)
+{
+ struct vfio_pci_device *vdev = device_data;
+
+ mutex_lock(&vdev->igate);
+
+ if (vdev->req_trigger) {
+ dev_dbg(&vdev->pdev->dev, "Requesting device from user\n");
+ eventfd_signal(vdev->req_trigger, 1);
+ }
+
+ mutex_unlock(&vdev->igate);
+}
+
static const struct vfio_device_ops vfio_pci_ops = {
.name = "vfio-pci",
.open = vfio_pci_open,
.read = vfio_pci_read,
.write = vfio_pci_write,
.mmap = vfio_pci_mmap,
+ .request = vfio_pci_request,
};
static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return 0;
}
-static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
- unsigned index, unsigned start,
- unsigned count, uint32_t flags, void *data)
+static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
+ uint32_t flags, void *data)
{
int32_t fd = *(int32_t *)data;
- if ((index != VFIO_PCI_ERR_IRQ_INDEX) ||
- !(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
+ if (!(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
return -EINVAL;
/* DATA_NONE/DATA_BOOL enables loopback testing */
if (flags & VFIO_IRQ_SET_DATA_NONE) {
- if (vdev->err_trigger)
- eventfd_signal(vdev->err_trigger, 1);
+ if (*ctx)
+ eventfd_signal(*ctx, 1);
return 0;
} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
uint8_t trigger = *(uint8_t *)data;
- if (trigger && vdev->err_trigger)
- eventfd_signal(vdev->err_trigger, 1);
+ if (trigger && *ctx)
+ eventfd_signal(*ctx, 1);
return 0;
}
/* Handle SET_DATA_EVENTFD */
if (fd == -1) {
- if (vdev->err_trigger)
- eventfd_ctx_put(vdev->err_trigger);
- vdev->err_trigger = NULL;
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+ *ctx = NULL;
return 0;
} else if (fd >= 0) {
struct eventfd_ctx *efdctx;
efdctx = eventfd_ctx_fdget(fd);
if (IS_ERR(efdctx))
return PTR_ERR(efdctx);
- if (vdev->err_trigger)
- eventfd_ctx_put(vdev->err_trigger);
- vdev->err_trigger = efdctx;
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+ *ctx = efdctx;
return 0;
} else
return -EINVAL;
}
+
+static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (index != VFIO_PCI_ERR_IRQ_INDEX)
+ return -EINVAL;
+
+ /*
+ * We should sanitize start & count, but that wasn't caught
+ * originally, so this IRQ index must forever ignore them :-(
+ */
+
+ return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data);
+}
+
+static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
+ unsigned index, unsigned start,
+ unsigned count, uint32_t flags, void *data)
+{
+ if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1)
+ return -EINVAL;
+
+ return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data);
+}
+
int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
unsigned index, unsigned start, unsigned count,
void *data)
func = vfio_pci_set_err_trigger;
break;
}
+ case VFIO_PCI_REQ_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = vfio_pci_set_req_trigger;
+ break;
+ }
}
if (!func)
struct pci_saved_state *pci_saved_state;
int refcnt;
struct eventfd_ctx *err_trigger;
+ struct eventfd_ctx *req_trigger;
};
#define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)
void *iommu_data;
};
+struct vfio_unbound_dev {
+ struct device *dev;
+ struct list_head unbound_next;
+};
+
struct vfio_group {
struct kref kref;
int minor;
struct notifier_block nb;
struct list_head vfio_next;
struct list_head container_next;
+ struct list_head unbound_list;
+ struct mutex unbound_lock;
atomic_t opened;
};
kref_init(&group->kref);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
+ INIT_LIST_HEAD(&group->unbound_list);
+ mutex_init(&group->unbound_lock);
atomic_set(&group->container_users, 0);
atomic_set(&group->opened, 0);
group->iommu_group = iommu_group;
static void vfio_group_release(struct kref *kref)
{
struct vfio_group *group = container_of(kref, struct vfio_group, kref);
+ struct vfio_unbound_dev *unbound, *tmp;
+ struct iommu_group *iommu_group = group->iommu_group;
WARN_ON(!list_empty(&group->device_list));
+ list_for_each_entry_safe(unbound, tmp,
+ &group->unbound_list, unbound_next) {
+ list_del(&unbound->unbound_next);
+ kfree(unbound);
+ }
+
device_destroy(vfio.class, MKDEV(MAJOR(vfio.group_devt), group->minor));
list_del(&group->vfio_next);
vfio_free_group_minor(group->minor);
vfio_group_unlock_and_free(group);
+ iommu_group_put(iommu_group);
}
static void vfio_group_put(struct vfio_group *group)
}
/*
- * A vfio group is viable for use by userspace if all devices are either
- * driver-less or bound to a vfio or whitelisted driver. We test the
- * latter by the existence of a struct vfio_device matching the dev.
+ * A vfio group is viable for use by userspace if all devices are in
+ * one of the following states:
+ * - driver-less
+ * - bound to a vfio driver
+ * - bound to a whitelisted driver
+ *
+ * We use two methods to determine whether a device is bound to a vfio
+ * driver. The first is to test whether the device exists in the vfio
+ * group. The second is to test if the device exists on the group
+ * unbound_list, indicating it's in the middle of transitioning from
+ * a vfio driver to driver-less.
*/
static int vfio_dev_viable(struct device *dev, void *data)
{
struct vfio_group *group = data;
struct vfio_device *device;
struct device_driver *drv = ACCESS_ONCE(dev->driver);
+ struct vfio_unbound_dev *unbound;
+ int ret = -EINVAL;
- if (!drv || vfio_whitelisted_driver(drv))
+ mutex_lock(&group->unbound_lock);
+ list_for_each_entry(unbound, &group->unbound_list, unbound_next) {
+ if (dev == unbound->dev) {
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&group->unbound_lock);
+
+ if (!ret || !drv || vfio_whitelisted_driver(drv))
return 0;
device = vfio_group_get_device(group, dev);
return 0;
}
- return -EINVAL;
+ return ret;
}
/**
{
struct vfio_group *group = container_of(nb, struct vfio_group, nb);
struct device *dev = data;
+ struct vfio_unbound_dev *unbound;
/*
* Need to go through a group_lock lookup to get a reference or we
* stop the system to maintain isolation. At a minimum, we'd
* want a toggle to disable driver auto probe for this device.
*/
+
+ mutex_lock(&group->unbound_lock);
+ list_for_each_entry(unbound,
+ &group->unbound_list, unbound_next) {
+ if (dev == unbound->dev) {
+ list_del(&unbound->unbound_next);
+ kfree(unbound);
+ break;
+ }
+ }
+ mutex_unlock(&group->unbound_lock);
break;
}
iommu_group_put(iommu_group);
return PTR_ERR(group);
}
+ } else {
+ /*
+ * A found vfio_group already holds a reference to the
+ * iommu_group. A created vfio_group keeps the reference.
+ */
+ iommu_group_put(iommu_group);
}
device = vfio_group_get_device(group, dev);
dev_name(dev), iommu_group_id(iommu_group));
vfio_device_put(device);
vfio_group_put(group);
- iommu_group_put(iommu_group);
return -EBUSY;
}
device = vfio_group_create_device(group, dev, ops, device_data);
if (IS_ERR(device)) {
vfio_group_put(group);
- iommu_group_put(iommu_group);
return PTR_ERR(device);
}
/*
- * Added device holds reference to iommu_group and vfio_device
- * (which in turn holds reference to vfio_group). Drop extra
- * group reference used while acquiring device.
+ * Drop all but the vfio_device reference. The vfio_device holds
+ * a reference to the vfio_group, which holds a reference to the
+ * iommu_group.
*/
vfio_group_put(group);
{
struct vfio_device *device = dev_get_drvdata(dev);
struct vfio_group *group = device->group;
- struct iommu_group *iommu_group = group->iommu_group;
void *device_data = device->device_data;
+ struct vfio_unbound_dev *unbound;
+ unsigned int i = 0;
/*
* The group exists so long as we have a device reference. Get
*/
vfio_group_get(group);
+ /*
+ * When the device is removed from the group, the group suddenly
+ * becomes non-viable; the device has a driver (until the unbind
+ * completes), but it's not present in the group. This is bad news
+ * for any external users that need to re-acquire a group reference
+ * in order to match and release their existing reference. To
+ * solve this, we track such devices on the unbound_list to bridge
+ * the gap until they're fully unbound.
+ */
+ unbound = kzalloc(sizeof(*unbound), GFP_KERNEL);
+ if (unbound) {
+ unbound->dev = dev;
+ mutex_lock(&group->unbound_lock);
+ list_add(&unbound->unbound_next, &group->unbound_list);
+ mutex_unlock(&group->unbound_lock);
+ }
+ WARN_ON(!unbound);
+
vfio_device_put(device);
- /* TODO send a signal to encourage this to be released */
- wait_event(vfio.release_q, !vfio_dev_present(group, dev));
+ /*
+ * If the device is still present in the group after the above
+ * 'put', then it is in use and we need to request it from the
+ * bus driver. The driver may in turn need to request the
+ * device from the user. We send the request on an arbitrary
+ * interval with counter to allow the driver to take escalating
+ * measures to release the device if it has the ability to do so.
+ */
+ do {
+ device = vfio_group_get_device(group, dev);
+ if (!device)
+ break;
- vfio_group_put(group);
+ if (device->ops->request)
+ device->ops->request(device_data, i++);
- iommu_group_put(iommu_group);
+ vfio_device_put(device);
+
+ } while (wait_event_interruptible_timeout(vfio.release_q,
+ !vfio_dev_present(group, dev),
+ HZ * 10) <= 0);
+
+ vfio_group_put(group);
return device_data;
}
struct list_head next;
struct list_head group_list;
int prot; /* IOMMU_CACHE */
+ bool fgsp; /* Fine-grained super pages */
};
struct vfio_dma {
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
bool lock_cap = capable(CAP_IPC_LOCK);
long ret, i;
+ bool rsvd;
if (!current->mm)
return -ENODEV;
if (ret)
return ret;
- if (is_invalid_reserved_pfn(*pfn_base))
- return 1;
+ rsvd = is_invalid_reserved_pfn(*pfn_base);
- if (!lock_cap && current->mm->locked_vm + 1 > limit) {
+ if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
limit << PAGE_SHIFT);
}
if (unlikely(disable_hugepages)) {
- vfio_lock_acct(1);
+ if (!rsvd)
+ vfio_lock_acct(1);
return 1;
}
if (ret)
break;
- if (pfn != *pfn_base + i || is_invalid_reserved_pfn(pfn)) {
+ if (pfn != *pfn_base + i ||
+ rsvd != is_invalid_reserved_pfn(pfn)) {
put_pfn(pfn, prot);
break;
}
- if (!lock_cap && current->mm->locked_vm + i + 1 > limit) {
+ if (!rsvd && !lock_cap &&
+ current->mm->locked_vm + i + 1 > limit) {
put_pfn(pfn, prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, limit << PAGE_SHIFT);
}
}
- vfio_lock_acct(i);
+ if (!rsvd)
+ vfio_lock_acct(i);
return i;
}
domain = d = list_first_entry(&iommu->domain_list,
struct vfio_domain, next);
- list_for_each_entry_continue(d, &iommu->domain_list, next)
+ list_for_each_entry_continue(d, &iommu->domain_list, next) {
iommu_unmap(d->domain, dma->iova, dma->size);
+ cond_resched();
+ }
while (iova < end) {
- size_t unmapped;
- phys_addr_t phys;
+ size_t unmapped, len;
+ phys_addr_t phys, next;
phys = iommu_iova_to_phys(domain->domain, iova);
if (WARN_ON(!phys)) {
continue;
}
- unmapped = iommu_unmap(domain->domain, iova, PAGE_SIZE);
+ /*
+ * To optimize for fewer iommu_unmap() calls, each of which
+ * may require hardware cache flushing, try to find the
+ * largest contiguous physical memory chunk to unmap.
+ */
+ for (len = PAGE_SIZE;
+ !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
+ next = iommu_iova_to_phys(domain->domain, iova + len);
+ if (next != phys + len)
+ break;
+ }
+
+ unmapped = iommu_unmap(domain->domain, iova, len);
if (WARN_ON(!unmapped))
break;
unmapped >> PAGE_SHIFT,
dma->prot, false);
iova += unmapped;
+
+ cond_resched();
}
vfio_lock_acct(-unlocked);
map_try_harder(d, iova, pfn, npage, prot))
goto unwind;
}
+
+ cond_resched();
}
return 0;
return 0;
}
+/*
+ * We change our unmap behavior slightly depending on whether the IOMMU
+ * supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage
+ * for practically any contiguous power-of-two mapping we give it. This means
+ * we don't need to look for contiguous chunks ourselves to make unmapping
+ * more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d
+ * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
+ * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
+ * hugetlbfs is in use.
+ */
+static void vfio_test_domain_fgsp(struct vfio_domain *domain)
+{
+ struct page *pages;
+ int ret, order = get_order(PAGE_SIZE * 2);
+
+ pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (!pages)
+ return;
+
+ ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
+ IOMMU_READ | IOMMU_WRITE | domain->prot);
+ if (!ret) {
+ size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
+
+ if (unmapped == PAGE_SIZE)
+ iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
+ else
+ domain->fgsp = true;
+ }
+
+ __free_pages(pages, order);
+}
+
static int vfio_iommu_type1_attach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
}
}
+ vfio_test_domain_fgsp(domain);
+
/* replay mappings on new domains */
ret = vfio_iommu_replay(iommu, domain);
if (ret)
* @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
* operations documented below
* @mmap: Perform mmap(2) on a region of the device file descriptor
+ * @request: Request for the bus driver to release the device
*/
struct vfio_device_ops {
char *name;
long (*ioctl)(void *device_data, unsigned int cmd,
unsigned long arg);
int (*mmap)(void *device_data, struct vm_area_struct *vma);
+ void (*request)(void *device_data, unsigned int count);
};
extern int vfio_add_group_dev(struct device *dev,
VFIO_PCI_MSI_IRQ_INDEX,
VFIO_PCI_MSIX_IRQ_INDEX,
VFIO_PCI_ERR_IRQ_INDEX,
+ VFIO_PCI_REQ_IRQ_INDEX,
VFIO_PCI_NUM_IRQS
};
projects / karo-tx-linux.git / commitdiff