Use a run-of-the-mill anonymous inode, there is nothing useful being provided by kvm_gmem_fs. Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- include/uapi/linux/magic.h | 1 - virt/kvm/guest_mem.c | 110 ++++++++++--------------------------- virt/kvm/kvm_main.c | 6 -- 3 files changed, 30 insertions(+), 87 deletions(-) diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index afe9c376c9a5..6325d1d0e90f 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h @@ -101,6 +101,5 @@ #define DMA_BUF_MAGIC 0x444d4142 /* "DMAB" */ #define DEVMEM_MAGIC 0x454d444d /* "DMEM" */ #define SECRETMEM_MAGIC 0x5345434d /* "SECM" */ -#define KVM_GUEST_MEMORY_MAGIC 0x474d454d /* "GMEM" */ #endif /* __LINUX_MAGIC_H__ */ diff --git a/virt/kvm/guest_mem.c b/virt/kvm/guest_mem.c index a819367434e9..73b841a2e1b1 100644 --- a/virt/kvm/guest_mem.c +++ b/virt/kvm/guest_mem.c @@ -3,14 +3,10 @@ #include <linux/falloc.h> #include <linux/kvm_host.h> #include <linux/pagemap.h> -#include <linux/pseudo_fs.h> - -#include <uapi/linux/magic.h> +#include <linux/anon_inodes.h> #include "kvm_mm.h" -static struct vfsmount *kvm_gmem_mnt; - struct kvm_gmem { struct kvm *kvm; struct xarray bindings; @@ -356,23 +352,40 @@ static const struct inode_operations kvm_gmem_iops = { .setattr = kvm_gmem_setattr, }; -static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags, - struct vfsmount *mnt) +static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) { const char *anon_name = "[kvm-gmem]"; - const struct qstr qname = QSTR_INIT(anon_name, strlen(anon_name)); struct kvm_gmem *gmem; struct inode *inode; struct file *file; int fd, err; - inode = alloc_anon_inode(mnt->mnt_sb); - if (IS_ERR(inode)) - return PTR_ERR(inode); + fd = get_unused_fd_flags(0); + if (fd < 0) + return fd; - err = security_inode_init_security_anon(inode, &qname, NULL); - if (err) - goto err_inode; + gmem = kzalloc(sizeof(*gmem), GFP_KERNEL); + if (!gmem) { + err = -ENOMEM; + goto err_fd; + } + + file = anon_inode_getfile(anon_name, &kvm_gmem_fops, gmem, + O_RDWR); + if (IS_ERR(file)) { + err = PTR_ERR(file); + goto err_gmem; + } + + file->f_flags |= O_LARGEFILE; + + kvm_get_kvm(kvm); + gmem->kvm = kvm; + xa_init(&gmem->bindings); + list_add(&gmem->entry, &file->f_mapping->private_list); + + inode = file->f_inode; + WARN_ON(file->f_mapping != inode->i_mapping); inode->i_private = (void *)(unsigned long)flags; inode->i_op = &kvm_gmem_iops; @@ -385,44 +398,13 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags, /* Unmovable mappings are supposed to be marked unevictable as well. */ WARN_ON_ONCE(!mapping_unevictable(inode->i_mapping)); - fd = get_unused_fd_flags(0); - if (fd < 0) { - err = fd; - goto err_inode; - } - - file = alloc_file_pseudo(inode, mnt, "kvm-gmem", O_RDWR, &kvm_gmem_fops); - if (IS_ERR(file)) { - err = PTR_ERR(file); - goto err_fd; - } - - file->f_flags |= O_LARGEFILE; - file->f_mapping = inode->i_mapping; - - gmem = kzalloc(sizeof(*gmem), GFP_KERNEL); - if (!gmem) { - err = -ENOMEM; - goto err_file; - } - - kvm_get_kvm(kvm); - gmem->kvm = kvm; - xa_init(&gmem->bindings); - - file->private_data = gmem; - - list_add(&gmem->entry, &inode->i_mapping->private_list); - fd_install(fd, file); return fd; -err_file: - fput(file); +err_gmem: + kfree(gmem); err_fd: put_unused_fd(fd); -err_inode: - iput(inode); return err; } @@ -455,7 +437,7 @@ int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *args) if (!kvm_gmem_is_valid_size(size, flags)) return -EINVAL; - return __kvm_gmem_create(kvm, size, flags, kvm_gmem_mnt); + return __kvm_gmem_create(kvm, size, flags); } int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot, @@ -603,35 +585,3 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, return r; } EXPORT_SYMBOL_GPL(kvm_gmem_get_pfn); - -static int kvm_gmem_init_fs_context(struct fs_context *fc) -{ - if (!init_pseudo(fc, KVM_GUEST_MEMORY_MAGIC)) - return -ENOMEM; - - return 0; -} - -static struct file_system_type kvm_gmem_fs = { - .name = "kvm_guest_memory", - .init_fs_context = kvm_gmem_init_fs_context, - .kill_sb = kill_anon_super, -}; - -int kvm_gmem_init(void) -{ - kvm_gmem_mnt = kern_mount(&kvm_gmem_fs); - if (IS_ERR(kvm_gmem_mnt)) - return PTR_ERR(kvm_gmem_mnt); - - /* For giggles. Userspace can never map this anyways. */ - kvm_gmem_mnt->mnt_flags |= MNT_NOEXEC; - - return 0; -} - -void kvm_gmem_exit(void) -{ - kern_unmount(kvm_gmem_mnt); - kvm_gmem_mnt = NULL; -} diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a83dfef1316e..4a1ded1faf84 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -6424,10 +6424,6 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) if (r) goto err_async_pf; - r = kvm_gmem_init(); - if (r) - goto err_gmem; - kvm_chardev_ops.owner = module; kvm_preempt_ops.sched_in = kvm_sched_in; @@ -6454,8 +6450,6 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) err_register: kvm_vfio_ops_exit(); err_vfio: - kvm_gmem_exit(); -err_gmem: kvm_async_pf_deinit(); err_async_pf: kvm_irqfd_exit(); -- 2.39.1