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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-12 13:11:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-12 13:11:26 -0700
commit467590e055f5c714fb457803250415879d0da9e5 (patch)
tree7533a26dcd19023d5eeac54f62432097c85f4ef3 /drivers/vfio
parent763f96944c954ce0e00a10a7bdfe29adbe4f92eb (diff)
parentc1abca96b252a9627f99f39215b84e5de92bf1e3 (diff)
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Merge tag 'vfio-v4.18-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson: - Bind type1 task tracking to group_leader to facilitate vCPU hotplug in QEMU (Alex Williamson) - Sample mdev display drivers, including region-based host and guest Linux drivers and bochs compatible dmabuf device (Gerd Hoffmann) - Fix vfio-platform reset module leak (Geert Uytterhoeven) - vfio-platform error message consistency (Geert Uytterhoeven) - Global checking for mdev uuid collisions rather than per parent device (Alex Williamson) - Use match_string() helper (Yisheng Xie) - vfio-platform PM domain fixes (Geert Uytterhoeven) - Fix sample mbochs driver build dependency (Arnd Bergmann) * tag 'vfio-v4.18-rc1' of git://github.com/awilliam/linux-vfio: samples: mbochs: add DMA_SHARED_BUFFER dependency vfio: platform: Fix using devices in PM Domains vfio: use match_string() helper vfio/mdev: Re-order sysfs attribute creation vfio/mdev: Check globally for duplicate devices vfio: platform: Make printed error messages more consistent vfio: platform: Fix reset module leak in error path sample: vfio bochs vbe display (host device for bochs-drm) sample: vfio mdev display - guest driver sample: vfio mdev display - host device vfio/type1: Fix task tracking for QEMU vCPU hotplug
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/mdev/mdev_core.c102
-rw-r--r--drivers/vfio/mdev/mdev_private.h2
-rw-r--r--drivers/vfio/mdev/mdev_sysfs.c14
-rw-r--r--drivers/vfio/platform/vfio_platform_common.c30
-rw-r--r--drivers/vfio/vfio.c11
-rw-r--r--drivers/vfio/vfio_iommu_type1.c73
6 files changed, 116 insertions, 116 deletions
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 126991046eb7..0212f0ee8aea 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -66,34 +66,6 @@ uuid_le mdev_uuid(struct mdev_device *mdev)
}
EXPORT_SYMBOL(mdev_uuid);
-static int _find_mdev_device(struct device *dev, void *data)
-{
- struct mdev_device *mdev;
-
- if (!dev_is_mdev(dev))
- return 0;
-
- mdev = to_mdev_device(dev);
-
- if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0)
- return 1;
-
- return 0;
-}
-
-static bool mdev_device_exist(struct mdev_parent *parent, uuid_le uuid)
-{
- struct device *dev;
-
- dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
- if (dev) {
- put_device(dev);
- return true;
- }
-
- return false;
-}
-
/* Should be called holding parent_list_lock */
static struct mdev_parent *__find_parent_device(struct device *dev)
{
@@ -221,7 +193,6 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
}
kref_init(&parent->ref);
- mutex_init(&parent->lock);
parent->dev = dev;
parent->ops = ops;
@@ -297,6 +268,10 @@ static void mdev_device_release(struct device *dev)
{
struct mdev_device *mdev = to_mdev_device(dev);
+ mutex_lock(&mdev_list_lock);
+ list_del(&mdev->next);
+ mutex_unlock(&mdev_list_lock);
+
dev_dbg(&mdev->dev, "MDEV: destroying\n");
kfree(mdev);
}
@@ -304,7 +279,7 @@ static void mdev_device_release(struct device *dev)
int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
{
int ret;
- struct mdev_device *mdev;
+ struct mdev_device *mdev, *tmp;
struct mdev_parent *parent;
struct mdev_type *type = to_mdev_type(kobj);
@@ -312,21 +287,28 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
if (!parent)
return -EINVAL;
- mutex_lock(&parent->lock);
+ mutex_lock(&mdev_list_lock);
/* Check for duplicate */
- if (mdev_device_exist(parent, uuid)) {
- ret = -EEXIST;
- goto create_err;
+ list_for_each_entry(tmp, &mdev_list, next) {
+ if (!uuid_le_cmp(tmp->uuid, uuid)) {
+ mutex_unlock(&mdev_list_lock);
+ ret = -EEXIST;
+ goto mdev_fail;
+ }
}
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev) {
+ mutex_unlock(&mdev_list_lock);
ret = -ENOMEM;
- goto create_err;
+ goto mdev_fail;
}
memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
+ list_add(&mdev->next, &mdev_list);
+ mutex_unlock(&mdev_list_lock);
+
mdev->parent = parent;
kref_init(&mdev->ref);
@@ -338,35 +320,28 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
ret = device_register(&mdev->dev);
if (ret) {
put_device(&mdev->dev);
- goto create_err;
+ goto mdev_fail;
}
ret = mdev_device_create_ops(kobj, mdev);
if (ret)
- goto create_failed;
+ goto create_fail;
ret = mdev_create_sysfs_files(&mdev->dev, type);
if (ret) {
mdev_device_remove_ops(mdev, true);
- goto create_failed;
+ goto create_fail;
}
mdev->type_kobj = kobj;
+ mdev->active = true;
dev_dbg(&mdev->dev, "MDEV: created\n");
- mutex_unlock(&parent->lock);
-
- mutex_lock(&mdev_list_lock);
- list_add(&mdev->next, &mdev_list);
- mutex_unlock(&mdev_list_lock);
-
- return ret;
+ return 0;
-create_failed:
+create_fail:
device_unregister(&mdev->dev);
-
-create_err:
- mutex_unlock(&parent->lock);
+mdev_fail:
mdev_put_parent(parent);
return ret;
}
@@ -377,44 +352,39 @@ int mdev_device_remove(struct device *dev, bool force_remove)
struct mdev_parent *parent;
struct mdev_type *type;
int ret;
- bool found = false;
mdev = to_mdev_device(dev);
mutex_lock(&mdev_list_lock);
list_for_each_entry(tmp, &mdev_list, next) {
- if (tmp == mdev) {
- found = true;
+ if (tmp == mdev)
break;
- }
}
- if (found)
- list_del(&mdev->next);
+ if (tmp != mdev) {
+ mutex_unlock(&mdev_list_lock);
+ return -ENODEV;
+ }
- mutex_unlock(&mdev_list_lock);
+ if (!mdev->active) {
+ mutex_unlock(&mdev_list_lock);
+ return -EAGAIN;
+ }
- if (!found)
- return -ENODEV;
+ mdev->active = false;
+ mutex_unlock(&mdev_list_lock);
type = to_mdev_type(mdev->type_kobj);
parent = mdev->parent;
- mutex_lock(&parent->lock);
ret = mdev_device_remove_ops(mdev, force_remove);
if (ret) {
- mutex_unlock(&parent->lock);
-
- mutex_lock(&mdev_list_lock);
- list_add(&mdev->next, &mdev_list);
- mutex_unlock(&mdev_list_lock);
-
+ mdev->active = true;
return ret;
}
mdev_remove_sysfs_files(dev, type);
device_unregister(dev);
- mutex_unlock(&parent->lock);
mdev_put_parent(parent);
return 0;
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index a9cefd70a705..b5819b7d7ef7 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -20,7 +20,6 @@ struct mdev_parent {
struct device *dev;
const struct mdev_parent_ops *ops;
struct kref ref;
- struct mutex lock;
struct list_head next;
struct kset *mdev_types_kset;
struct list_head type_list;
@@ -34,6 +33,7 @@ struct mdev_device {
struct kref ref;
struct list_head next;
struct kobject *type_kobj;
+ bool active;
};
#define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 802df210929b..249472f05509 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -257,24 +257,24 @@ int mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
{
int ret;
- ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
- if (ret)
- return ret;
-
ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
if (ret)
- goto device_link_failed;
+ return ret;
ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
if (ret)
goto type_link_failed;
+ ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
+ if (ret)
+ goto create_files_failed;
+
return ret;
+create_files_failed:
+ sysfs_remove_link(&dev->kobj, "mdev_type");
type_link_failed:
sysfs_remove_link(type->devices_kobj, dev_name(dev));
-device_link_failed:
- sysfs_remove_files(&dev->kobj, mdev_device_attrs);
return ret;
}
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 4c27f4be3c3d..c0cd824be2b7 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -17,6 +17,7 @@
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
@@ -239,6 +240,7 @@ static void vfio_platform_release(void *device_data)
ret, extra_dbg ? extra_dbg : "");
WARN_ON(1);
}
+ pm_runtime_put(vdev->device);
vfio_platform_regions_cleanup(vdev);
vfio_platform_irq_cleanup(vdev);
}
@@ -269,6 +271,10 @@ static int vfio_platform_open(void *device_data)
if (ret)
goto err_irq;
+ ret = pm_runtime_get_sync(vdev->device);
+ if (ret < 0)
+ goto err_pm;
+
ret = vfio_platform_call_reset(vdev, &extra_dbg);
if (ret && vdev->reset_required) {
dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
@@ -283,6 +289,8 @@ static int vfio_platform_open(void *device_data)
return 0;
err_rst:
+ pm_runtime_put(vdev->device);
+err_pm:
vfio_platform_irq_cleanup(vdev);
err_irq:
vfio_platform_regions_cleanup(vdev);
@@ -630,8 +638,7 @@ static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
ret = device_property_read_string(dev, "compatible",
&vdev->compat);
if (ret)
- pr_err("VFIO: cannot retrieve compat for %s\n",
- vdev->name);
+ pr_err("VFIO: Cannot retrieve compat for %s\n", vdev->name);
return ret;
}
@@ -673,7 +680,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
ret = vfio_platform_get_reset(vdev);
if (ret && vdev->reset_required) {
- pr_err("vfio: no reset function found for device %s\n",
+ pr_err("VFIO: No reset function found for device %s\n",
vdev->name);
return ret;
}
@@ -681,18 +688,24 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
group = vfio_iommu_group_get(dev);
if (!group) {
pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
- return -EINVAL;
+ ret = -EINVAL;
+ goto put_reset;
}
ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
- if (ret) {
- vfio_iommu_group_put(group, dev);
- return ret;
- }
+ if (ret)
+ goto put_iommu;
mutex_init(&vdev->igate);
+ pm_runtime_enable(vdev->device);
return 0;
+
+put_iommu:
+ vfio_iommu_group_put(group, dev);
+put_reset:
+ vfio_platform_put_reset(vdev);
+ return ret;
}
EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
@@ -703,6 +716,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
vdev = vfio_del_group_dev(dev);
if (vdev) {
+ pm_runtime_disable(vdev->device);
vfio_platform_put_reset(vdev);
vfio_iommu_group_put(dev->iommu_group, dev);
}
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 721f97f8dac1..64833879f75d 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -630,8 +630,6 @@ static const char * const vfio_driver_whitelist[] = { "pci-stub" };
static bool vfio_dev_whitelisted(struct device *dev, struct device_driver *drv)
{
- int i;
-
if (dev_is_pci(dev)) {
struct pci_dev *pdev = to_pci_dev(dev);
@@ -639,12 +637,9 @@ static bool vfio_dev_whitelisted(struct device *dev, struct device_driver *drv)
return true;
}
- for (i = 0; i < ARRAY_SIZE(vfio_driver_whitelist); i++) {
- if (!strcmp(drv->name, vfio_driver_whitelist[i]))
- return true;
- }
-
- return false;
+ return match_string(vfio_driver_whitelist,
+ ARRAY_SIZE(vfio_driver_whitelist),
+ drv->name) >= 0;
}
/*
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 3c082451ab1a..2c75b33db4ac 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -83,6 +83,7 @@ struct vfio_dma {
size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
bool iommu_mapped;
+ bool lock_cap; /* capable(CAP_IPC_LOCK) */
struct task_struct *task;
struct rb_root pfn_list; /* Ex-user pinned pfn list */
};
@@ -253,29 +254,25 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
return ret;
}
-static int vfio_lock_acct(struct task_struct *task, long npage, bool *lock_cap)
+static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
{
struct mm_struct *mm;
- bool is_current;
int ret;
if (!npage)
return 0;
- is_current = (task->mm == current->mm);
-
- mm = is_current ? task->mm : get_task_mm(task);
+ mm = async ? get_task_mm(dma->task) : dma->task->mm;
if (!mm)
return -ESRCH; /* process exited */
ret = down_write_killable(&mm->mmap_sem);
if (!ret) {
if (npage > 0) {
- if (lock_cap ? !*lock_cap :
- !has_capability(task, CAP_IPC_LOCK)) {
+ if (!dma->lock_cap) {
unsigned long limit;
- limit = task_rlimit(task,
+ limit = task_rlimit(dma->task,
RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (mm->locked_vm + npage > limit)
@@ -289,7 +286,7 @@ static int vfio_lock_acct(struct task_struct *task, long npage, bool *lock_cap)
up_write(&mm->mmap_sem);
}
- if (!is_current)
+ if (async)
mmput(mm);
return ret;
@@ -400,7 +397,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
*/
static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
long npage, unsigned long *pfn_base,
- bool lock_cap, unsigned long limit)
+ unsigned long limit)
{
unsigned long pfn = 0;
long ret, pinned = 0, lock_acct = 0;
@@ -423,7 +420,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
* pages are already counted against the user.
*/
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
- if (!lock_cap && current->mm->locked_vm + 1 > limit) {
+ if (!dma->lock_cap && current->mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
limit << PAGE_SHIFT);
@@ -449,7 +446,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
}
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
- if (!lock_cap &&
+ if (!dma->lock_cap &&
current->mm->locked_vm + lock_acct + 1 > limit) {
put_pfn(pfn, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
@@ -462,7 +459,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
}
out:
- ret = vfio_lock_acct(current, lock_acct, &lock_cap);
+ ret = vfio_lock_acct(dma, lock_acct, false);
unpin_out:
if (ret) {
@@ -493,7 +490,7 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
}
if (do_accounting)
- vfio_lock_acct(dma->task, locked - unlocked, NULL);
+ vfio_lock_acct(dma, locked - unlocked, true);
return unlocked;
}
@@ -510,7 +507,7 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
if (!ret && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
- ret = vfio_lock_acct(dma->task, 1, NULL);
+ ret = vfio_lock_acct(dma, 1, true);
if (ret) {
put_pfn(*pfn_base, dma->prot);
if (ret == -ENOMEM)
@@ -537,7 +534,7 @@ static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
if (do_accounting)
- vfio_lock_acct(dma->task, -unlocked, NULL);
+ vfio_lock_acct(dma, -unlocked, true);
return unlocked;
}
@@ -829,7 +826,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list);
if (do_accounting) {
- vfio_lock_acct(dma->task, -unlocked, NULL);
+ vfio_lock_acct(dma, -unlocked, true);
return 0;
}
return unlocked;
@@ -1044,14 +1041,12 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
size_t size = map_size;
long npage;
unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- bool lock_cap = capable(CAP_IPC_LOCK);
int ret = 0;
while (size) {
/* Pin a contiguous chunk of memory */
npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
- size >> PAGE_SHIFT, &pfn,
- lock_cap, limit);
+ size >> PAGE_SHIFT, &pfn, limit);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
@@ -1126,8 +1121,36 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
dma->iova = iova;
dma->vaddr = vaddr;
dma->prot = prot;
- get_task_struct(current);
- dma->task = current;
+
+ /*
+ * We need to be able to both add to a task's locked memory and test
+ * against the locked memory limit and we need to be able to do both
+ * outside of this call path as pinning can be asynchronous via the
+ * external interfaces for mdev devices. RLIMIT_MEMLOCK requires a
+ * task_struct and VM locked pages requires an mm_struct, however
+ * holding an indefinite mm reference is not recommended, therefore we
+ * only hold a reference to a task. We could hold a reference to
+ * current, however QEMU uses this call path through vCPU threads,
+ * which can be killed resulting in a NULL mm and failure in the unmap
+ * path when called via a different thread. Avoid this problem by
+ * using the group_leader as threads within the same group require
+ * both CLONE_THREAD and CLONE_VM and will therefore use the same
+ * mm_struct.
+ *
+ * Previously we also used the task for testing CAP_IPC_LOCK at the
+ * time of pinning and accounting, however has_capability() makes use
+ * of real_cred, a copy-on-write field, so we can't guarantee that it
+ * matches group_leader, or in fact that it might not change by the
+ * time it's evaluated. If a process were to call MAP_DMA with
+ * CAP_IPC_LOCK but later drop it, it doesn't make sense that they
+ * possibly see different results for an iommu_mapped vfio_dma vs
+ * externally mapped. Therefore track CAP_IPC_LOCK in vfio_dma at the
+ * time of calling MAP_DMA.
+ */
+ get_task_struct(current->group_leader);
+ dma->task = current->group_leader;
+ dma->lock_cap = capable(CAP_IPC_LOCK);
+
dma->pfn_list = RB_ROOT;
/* Insert zero-sized and grow as we map chunks of it */
@@ -1162,7 +1185,6 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
struct vfio_domain *d;
struct rb_node *n;
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- bool lock_cap = capable(CAP_IPC_LOCK);
int ret;
/* Arbitrarily pick the first domain in the list for lookups */
@@ -1209,8 +1231,7 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
npage = vfio_pin_pages_remote(dma, vaddr,
n >> PAGE_SHIFT,
- &pfn, lock_cap,
- limit);
+ &pfn, limit);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
@@ -1487,7 +1508,7 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
if (!is_invalid_reserved_pfn(vpfn->pfn))
locked++;
}
- vfio_lock_acct(dma->task, locked - unlocked, NULL);
+ vfio_lock_acct(dma, locked - unlocked, true);
}
}