From: Paolo Bonzini <[email protected]>

Add a new VM ioctl to create a new plane. It returns a new file
descriptor which supports per-plane ioctls.

Signed-off-by: Paolo Bonzini <[email protected]>
Co-developed-by: Joerg Roedel <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
---
 include/uapi/linux/kvm.h |  2 ++
 virt/kvm/kvm_main.c      | 75 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 813f964a6dc1..24e34b8e4819 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1355,6 +1355,8 @@ struct kvm_s390_keyop {
 #define KVM_GET_DEVICE_ATTR      _IOW(KVMIO,  0xe2, struct kvm_device_attr)
 #define KVM_HAS_DEVICE_ATTR      _IOW(KVMIO,  0xe3, struct kvm_device_attr)
 
+#define KVM_CREATE_PLANE         _IO(KVMIO, 0xe4)
+
 /*
  * ioctls for vcpu fds
  */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5a0277e2ac7c..03a44ff62f0f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4843,6 +4843,34 @@ static long kvm_vcpu_compat_ioctl(struct file *filp,
 }
 #endif
 
+static long kvm_plane_ioctl(struct file *filp, unsigned int ioctl,
+                           unsigned long arg)
+{
+       struct kvm_plane *plane = filp->private_data;
+
+       if (plane->kvm->mm != current->mm || plane->kvm->vm_dead)
+               return -EIO;
+
+       switch (ioctl) {
+       default:
+               return -ENOTTY;
+       }
+}
+
+static int kvm_plane_release(struct inode *inode, struct file *filp)
+{
+       struct kvm_plane *plane = filp->private_data;
+
+       kvm_put_kvm(plane->kvm);
+       return 0;
+}
+
+static struct file_operations kvm_plane_fops = {
+       .unlocked_ioctl = kvm_plane_ioctl,
+       .release = kvm_plane_release,
+       KVM_COMPAT(kvm_plane_ioctl),
+};
+
 static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma)
 {
        struct kvm_device *dev = filp->private_data;
@@ -5288,6 +5316,49 @@ static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
        return fd;
 }
 
+static int kvm_vm_ioctl_create_plane(struct kvm *kvm, unsigned id)
+{
+       struct kvm_plane *plane;
+       struct file *file;
+       int r, fd;
+
+       if (id >= kvm_arch_max_planes(kvm) ||
+           WARN_ON_ONCE(id >= KVM_MAX_PLANES))
+               return -EINVAL;
+
+       guard(mutex)(&kvm->lock);
+       if (kvm->planes[id])
+               return -EEXIST;
+
+       fd = get_unused_fd_flags(O_CLOEXEC);
+       if (fd < 0)
+               return fd;
+
+       plane = kvm_create_plane(kvm, id);
+       if (!plane) {
+               r = -ENOMEM;
+               goto put_fd;
+       }
+
+       kvm_get_kvm(kvm);
+       file = anon_inode_getfile("kvm-plane", &kvm_plane_fops, plane, O_RDWR);
+       if (IS_ERR(file)) {
+               r = PTR_ERR(file);
+               goto put_kvm;
+       }
+
+       fd_install(fd, file);
+       return fd;
+
+put_kvm:
+       kvm_put_kvm(kvm);
+       kvm_destroy_one_plane(plane);
+put_fd:
+       put_unused_fd(fd);
+       return r;
+}
+
+
 #define SANITY_CHECK_MEM_REGION_FIELD(field)                                   
\
 do {                                                                           
\
        BUILD_BUG_ON(offsetof(struct kvm_userspace_memory_region, field) !=     
        \
@@ -5306,6 +5377,9 @@ static long kvm_vm_ioctl(struct file *filp,
        if (kvm->mm != current->mm || kvm->vm_dead)
                return -EIO;
        switch (ioctl) {
+       case KVM_CREATE_PLANE:
+               r = kvm_vm_ioctl_create_plane(kvm, arg);
+               break;
        case KVM_CREATE_VCPU:
                r = kvm_vm_ioctl_create_vcpu(kvm, arg);
                break;
@@ -6676,6 +6750,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, 
struct module *module)
        kvm_chardev_ops.owner = module;
        kvm_vm_fops.owner = module;
        kvm_vcpu_fops.owner = module;
+       kvm_plane_fops.owner = module;
        kvm_device_fops.owner = module;
 
        kvm_preempt_ops.sched_in = kvm_sched_in;
-- 
2.53.0


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