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-rw-r--r--virt/kvm/vfio.c394
1 files changed, 394 insertions, 0 deletions
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
new file mode 100644
index 0000000000..ca24ce1209
--- /dev/null
+++ b/virt/kvm/vfio.c
@@ -0,0 +1,394 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VFIO-KVM bridge pseudo device
+ *
+ * Copyright (C) 2013 Red Hat, Inc. All rights reserved.
+ * Author: Alex Williamson <alex.williamson@redhat.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/kvm_host.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include "vfio.h"
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+#include <asm/kvm_ppc.h>
+#endif
+
+struct kvm_vfio_file {
+ struct list_head node;
+ struct file *file;
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+ struct iommu_group *iommu_group;
+#endif
+};
+
+struct kvm_vfio {
+ struct list_head file_list;
+ struct mutex lock;
+ bool noncoherent;
+};
+
+static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+ void (*fn)(struct file *file, struct kvm *kvm);
+
+ fn = symbol_get(vfio_file_set_kvm);
+ if (!fn)
+ return;
+
+ fn(file, kvm);
+
+ symbol_put(vfio_file_set_kvm);
+}
+
+static bool kvm_vfio_file_enforced_coherent(struct file *file)
+{
+ bool (*fn)(struct file *file);
+ bool ret;
+
+ fn = symbol_get(vfio_file_enforced_coherent);
+ if (!fn)
+ return false;
+
+ ret = fn(file);
+
+ symbol_put(vfio_file_enforced_coherent);
+
+ return ret;
+}
+
+static bool kvm_vfio_file_is_valid(struct file *file)
+{
+ bool (*fn)(struct file *file);
+ bool ret;
+
+ fn = symbol_get(vfio_file_is_valid);
+ if (!fn)
+ return false;
+
+ ret = fn(file);
+
+ symbol_put(vfio_file_is_valid);
+
+ return ret;
+}
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
+{
+ struct iommu_group *(*fn)(struct file *file);
+ struct iommu_group *ret;
+
+ fn = symbol_get(vfio_file_iommu_group);
+ if (!fn)
+ return NULL;
+
+ ret = fn(file);
+
+ symbol_put(vfio_file_iommu_group);
+
+ return ret;
+}
+
+static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
+ struct kvm_vfio_file *kvf)
+{
+ if (WARN_ON_ONCE(!kvf->iommu_group))
+ return;
+
+ kvm_spapr_tce_release_iommu_group(kvm, kvf->iommu_group);
+ iommu_group_put(kvf->iommu_group);
+ kvf->iommu_group = NULL;
+}
+#endif
+
+/*
+ * Groups/devices can use the same or different IOMMU domains. If the same
+ * then adding a new group/device may change the coherency of groups/devices
+ * we've previously been told about. We don't want to care about any of
+ * that so we retest each group/device and bail as soon as we find one that's
+ * noncoherent. This means we only ever [un]register_noncoherent_dma once
+ * for the whole device.
+ */
+static void kvm_vfio_update_coherency(struct kvm_device *dev)
+{
+ struct kvm_vfio *kv = dev->private;
+ bool noncoherent = false;
+ struct kvm_vfio_file *kvf;
+
+ list_for_each_entry(kvf, &kv->file_list, node) {
+ if (!kvm_vfio_file_enforced_coherent(kvf->file)) {
+ noncoherent = true;
+ break;
+ }
+ }
+
+ if (noncoherent != kv->noncoherent) {
+ kv->noncoherent = noncoherent;
+
+ if (kv->noncoherent)
+ kvm_arch_register_noncoherent_dma(dev->kvm);
+ else
+ kvm_arch_unregister_noncoherent_dma(dev->kvm);
+ }
+}
+
+static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd)
+{
+ struct kvm_vfio *kv = dev->private;
+ struct kvm_vfio_file *kvf;
+ struct file *filp;
+ int ret = 0;
+
+ filp = fget(fd);
+ if (!filp)
+ return -EBADF;
+
+ /* Ensure the FD is a vfio FD. */
+ if (!kvm_vfio_file_is_valid(filp)) {
+ ret = -EINVAL;
+ goto out_fput;
+ }
+
+ mutex_lock(&kv->lock);
+
+ list_for_each_entry(kvf, &kv->file_list, node) {
+ if (kvf->file == filp) {
+ ret = -EEXIST;
+ goto out_unlock;
+ }
+ }
+
+ kvf = kzalloc(sizeof(*kvf), GFP_KERNEL_ACCOUNT);
+ if (!kvf) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ kvf->file = get_file(filp);
+ list_add_tail(&kvf->node, &kv->file_list);
+
+ kvm_arch_start_assignment(dev->kvm);
+ kvm_vfio_file_set_kvm(kvf->file, dev->kvm);
+ kvm_vfio_update_coherency(dev);
+
+out_unlock:
+ mutex_unlock(&kv->lock);
+out_fput:
+ fput(filp);
+ return ret;
+}
+
+static int kvm_vfio_file_del(struct kvm_device *dev, unsigned int fd)
+{
+ struct kvm_vfio *kv = dev->private;
+ struct kvm_vfio_file *kvf;
+ struct fd f;
+ int ret;
+
+ f = fdget(fd);
+ if (!f.file)
+ return -EBADF;
+
+ ret = -ENOENT;
+
+ mutex_lock(&kv->lock);
+
+ list_for_each_entry(kvf, &kv->file_list, node) {
+ if (kvf->file != f.file)
+ continue;
+
+ list_del(&kvf->node);
+ kvm_arch_end_assignment(dev->kvm);
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+ kvm_spapr_tce_release_vfio_group(dev->kvm, kvf);
+#endif
+ kvm_vfio_file_set_kvm(kvf->file, NULL);
+ fput(kvf->file);
+ kfree(kvf);
+ ret = 0;
+ break;
+ }
+
+ kvm_vfio_update_coherency(dev);
+
+ mutex_unlock(&kv->lock);
+
+ fdput(f);
+
+ return ret;
+}
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
+ void __user *arg)
+{
+ struct kvm_vfio_spapr_tce param;
+ struct kvm_vfio *kv = dev->private;
+ struct kvm_vfio_file *kvf;
+ struct fd f;
+ int ret;
+
+ if (copy_from_user(&param, arg, sizeof(struct kvm_vfio_spapr_tce)))
+ return -EFAULT;
+
+ f = fdget(param.groupfd);
+ if (!f.file)
+ return -EBADF;
+
+ ret = -ENOENT;
+
+ mutex_lock(&kv->lock);
+
+ list_for_each_entry(kvf, &kv->file_list, node) {
+ if (kvf->file != f.file)
+ continue;
+
+ if (!kvf->iommu_group) {
+ kvf->iommu_group = kvm_vfio_file_iommu_group(kvf->file);
+ if (WARN_ON_ONCE(!kvf->iommu_group)) {
+ ret = -EIO;
+ goto err_fdput;
+ }
+ }
+
+ ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
+ kvf->iommu_group);
+ break;
+ }
+
+err_fdput:
+ mutex_unlock(&kv->lock);
+ fdput(f);
+ return ret;
+}
+#endif
+
+static int kvm_vfio_set_file(struct kvm_device *dev, long attr,
+ void __user *arg)
+{
+ int32_t __user *argp = arg;
+ int32_t fd;
+
+ switch (attr) {
+ case KVM_DEV_VFIO_FILE_ADD:
+ if (get_user(fd, argp))
+ return -EFAULT;
+ return kvm_vfio_file_add(dev, fd);
+
+ case KVM_DEV_VFIO_FILE_DEL:
+ if (get_user(fd, argp))
+ return -EFAULT;
+ return kvm_vfio_file_del(dev, fd);
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+ case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
+ return kvm_vfio_file_set_spapr_tce(dev, arg);
+#endif
+ }
+
+ return -ENXIO;
+}
+
+static int kvm_vfio_set_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_VFIO_FILE:
+ return kvm_vfio_set_file(dev, attr->attr,
+ u64_to_user_ptr(attr->addr));
+ }
+
+ return -ENXIO;
+}
+
+static int kvm_vfio_has_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_VFIO_FILE:
+ switch (attr->attr) {
+ case KVM_DEV_VFIO_FILE_ADD:
+ case KVM_DEV_VFIO_FILE_DEL:
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+ case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
+#endif
+ return 0;
+ }
+
+ break;
+ }
+
+ return -ENXIO;
+}
+
+static void kvm_vfio_release(struct kvm_device *dev)
+{
+ struct kvm_vfio *kv = dev->private;
+ struct kvm_vfio_file *kvf, *tmp;
+
+ list_for_each_entry_safe(kvf, tmp, &kv->file_list, node) {
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+ kvm_spapr_tce_release_vfio_group(dev->kvm, kvf);
+#endif
+ kvm_vfio_file_set_kvm(kvf->file, NULL);
+ fput(kvf->file);
+ list_del(&kvf->node);
+ kfree(kvf);
+ kvm_arch_end_assignment(dev->kvm);
+ }
+
+ kvm_vfio_update_coherency(dev);
+
+ kfree(kv);
+ kfree(dev); /* alloc by kvm_ioctl_create_device, free by .release */
+}
+
+static int kvm_vfio_create(struct kvm_device *dev, u32 type);
+
+static struct kvm_device_ops kvm_vfio_ops = {
+ .name = "kvm-vfio",
+ .create = kvm_vfio_create,
+ .release = kvm_vfio_release,
+ .set_attr = kvm_vfio_set_attr,
+ .has_attr = kvm_vfio_has_attr,
+};
+
+static int kvm_vfio_create(struct kvm_device *dev, u32 type)
+{
+ struct kvm_device *tmp;
+ struct kvm_vfio *kv;
+
+ /* Only one VFIO "device" per VM */
+ list_for_each_entry(tmp, &dev->kvm->devices, vm_node)
+ if (tmp->ops == &kvm_vfio_ops)
+ return -EBUSY;
+
+ kv = kzalloc(sizeof(*kv), GFP_KERNEL_ACCOUNT);
+ if (!kv)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&kv->file_list);
+ mutex_init(&kv->lock);
+
+ dev->private = kv;
+
+ return 0;
+}
+
+int kvm_vfio_ops_init(void)
+{
+ return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO);
+}
+
+void kvm_vfio_ops_exit(void)
+{
+ kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO);
+}