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-rw-r--r--Documentation/vfio.txt8
-rw-r--r--drivers/vfio/pci/vfio_pci.c286
-rw-r--r--drivers/vfio/pci/vfio_pci_config.c11
-rw-r--r--drivers/vfio/pci/vfio_pci_intrs.c35
-rw-r--r--drivers/vfio/vfio.c64
-rw-r--r--include/linux/vfio.h7
-rw-r--r--include/uapi/linux/vfio.h38
7 files changed, 421 insertions, 28 deletions
diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
index d7993dcf8537..b9ca02370d46 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, &reg);
+ 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 cef6002acbd4..6ab71b9fcf8d 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 affa34745be9..ffd0632c3cbc 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 4bc704e1b7c7..641bc87bdb96 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 842f4507883e..1eab4ace0671 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 ac8d488e4372..24579a0312a0 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 916e444e6f74..0fd47f5bc146 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 -------- */
/**
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 18:28:37 +0000