diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-10-16 10:28:53 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-10-20 06:30:46 -0700 |
| commit | e66438bb81c4ca773b51292c27e6b5baa34f9a5e (patch) | |
| tree | f69b9d710956f3ed2ec820875cb520e37e8e483c | |
| parent | 38ccc50ac037ab79609c33556b696064ef52521c (diff) | |
KVM: guest_memfd: Add gmem_inode.flags field instead of using i_private
Track a guest_memfd instance's flags in gmem_inode instead of burying them
in i_private. Burning an extra 8 bytes per inode is well worth the added
clarity provided by explicit tracking.
Reviewed-by: Shivank Garg <shivankg@amd.com>
Tested-by: Shivank Garg <shivankg@amd.com>
Link: https://lore.kernel.org/r/20251016172853.52451-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | virt/kvm/guest_memfd.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 4463643bd0a2..20f6e7fab58d 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -30,6 +30,8 @@ struct gmem_file { struct gmem_inode { struct shared_policy policy; struct inode vfs_inode; + + u64 flags; }; static __always_inline struct gmem_inode *GMEM_I(struct inode *inode) @@ -154,7 +156,7 @@ static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index) static enum kvm_gfn_range_filter kvm_gmem_get_invalidate_filter(struct inode *inode) { - if ((u64)inode->i_private & GUEST_MEMFD_FLAG_INIT_SHARED) + if (GMEM_I(inode)->flags & GUEST_MEMFD_FLAG_INIT_SHARED) return KVM_FILTER_SHARED; return KVM_FILTER_PRIVATE; @@ -385,9 +387,7 @@ static inline struct file *kvm_gmem_get_file(struct kvm_memory_slot *slot) static bool kvm_gmem_supports_mmap(struct inode *inode) { - const u64 flags = (u64)inode->i_private; - - return flags & GUEST_MEMFD_FLAG_MMAP; + return GMEM_I(inode)->flags & GUEST_MEMFD_FLAG_MMAP; } static vm_fault_t kvm_gmem_fault_user_mapping(struct vm_fault *vmf) @@ -399,7 +399,7 @@ static vm_fault_t kvm_gmem_fault_user_mapping(struct vm_fault *vmf) if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode)) return VM_FAULT_SIGBUS; - if (!((u64)inode->i_private & GUEST_MEMFD_FLAG_INIT_SHARED)) + if (!(GMEM_I(inode)->flags & GUEST_MEMFD_FLAG_INIT_SHARED)) return VM_FAULT_SIGBUS; folio = kvm_gmem_get_folio(inode, vmf->pgoff); @@ -588,7 +588,6 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) goto err_fops; } - inode->i_private = (void *)(unsigned long)flags; inode->i_op = &kvm_gmem_iops; inode->i_mapping->a_ops = &kvm_gmem_aops; inode->i_mode |= S_IFREG; @@ -598,6 +597,8 @@ 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)); + GMEM_I(inode)->flags = flags; + file = alloc_file_pseudo(inode, kvm_gmem_mnt, name, O_RDWR, &kvm_gmem_fops); if (IS_ERR(file)) { err = PTR_ERR(file); @@ -917,6 +918,8 @@ static struct inode *kvm_gmem_alloc_inode(struct super_block *sb) return NULL; mpol_shared_policy_init(&gi->policy, NULL); + + gi->flags = 0; return &gi->vfs_inode; } |