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Hallyn" Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , Yu Zhang , Isaku Yamahata , Xu Yilun , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" TODO: writeme Signed-off-by: Sean Christopherson --- include/uapi/linux/kvm.h | 2 ++ virt/kvm/guest_mem.c | 54 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 51 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index b6f90a273e2e..2df18796fd8e 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -2314,6 +2314,8 @@ struct kvm_memory_attributes { =20 #define KVM_CREATE_GUEST_MEMFD _IOWR(KVMIO, 0xd4, struct kvm_create_guest= _memfd) =20 +#define KVM_GUEST_MEMFD_ALLOW_HUGEPAGE (1ULL << 0) + struct kvm_create_guest_memfd { __u64 size; __u64 flags; diff --git a/virt/kvm/guest_mem.c b/virt/kvm/guest_mem.c index 0dd3f836cf9c..a819367434e9 100644 --- a/virt/kvm/guest_mem.c +++ b/virt/kvm/guest_mem.c @@ -17,15 +17,48 @@ struct kvm_gmem { struct list_head entry; }; =20 -static struct folio *kvm_gmem_get_folio(struct file *file, pgoff_t index) +static struct folio *kvm_gmem_get_huge_folio(struct inode *inode, pgoff_t = index) { +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + unsigned long huge_index =3D round_down(index, HPAGE_PMD_NR); + unsigned long flags =3D (unsigned long)inode->i_private; + struct address_space *mapping =3D inode->i_mapping; + gfp_t gfp =3D mapping_gfp_mask(mapping); struct folio *folio; =20 - /* TODO: Support huge pages. */ - folio =3D filemap_grab_folio(file->f_mapping, index); - if (IS_ERR_OR_NULL(folio)) + if (!(flags & KVM_GUEST_MEMFD_ALLOW_HUGEPAGE)) return NULL; =20 + if (filemap_range_has_page(mapping, huge_index << PAGE_SHIFT, + (huge_index + HPAGE_PMD_NR - 1) << PAGE_SHIFT)) + return NULL; + + folio =3D filemap_alloc_folio(gfp, HPAGE_PMD_ORDER); + if (!folio) + return NULL; + + if (filemap_add_folio(mapping, folio, huge_index, gfp)) { + folio_put(folio); + return NULL; + } + + return folio; +#else + return NULL; +#endif +} + +static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index) +{ + struct folio *folio; + + folio =3D kvm_gmem_get_huge_folio(inode, index); + if (!folio) { + folio =3D filemap_grab_folio(inode->i_mapping, index); + if (IS_ERR_OR_NULL(folio)) + return NULL; + } + /* * Use the up-to-date flag to track whether or not the memory has been * zeroed before being handed off to the guest. There is no backing @@ -323,7 +356,8 @@ static const struct inode_operations kvm_gmem_iops =3D { .setattr =3D kvm_gmem_setattr, }; =20 -static int __kvm_gmem_create(struct kvm *kvm, loff_t size, struct vfsmount= *mnt) +static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags, + struct vfsmount *mnt) { const char *anon_name =3D "[kvm-gmem]"; const struct qstr qname =3D QSTR_INIT(anon_name, strlen(anon_name)); @@ -346,6 +380,7 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t si= ze, struct vfsmount *mnt) inode->i_mode |=3D S_IFREG; inode->i_size =3D size; mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); + mapping_set_large_folios(inode->i_mapping); mapping_set_unmovable(inode->i_mapping); /* Unmovable mappings are supposed to be marked unevictable as well. */ WARN_ON_ONCE(!mapping_unevictable(inode->i_mapping)); @@ -396,6 +431,12 @@ static bool kvm_gmem_is_valid_size(loff_t size, u64 fl= ags) if (size < 0 || !PAGE_ALIGNED(size)) return false; =20 +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + if ((flags & KVM_GUEST_MEMFD_ALLOW_HUGEPAGE) && + !IS_ALIGNED(size, HPAGE_PMD_SIZE)) + return false; +#endif + return true; } =20 @@ -405,6 +446,9 @@ int kvm_gmem_create(struct kvm *kvm, struct kvm_create_= guest_memfd *args) u64 flags =3D args->flags; u64 valid_flags =3D 0; =20 + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + valid_flags |=3D KVM_GUEST_MEMFD_ALLOW_HUGEPAGE; + if (flags & ~valid_flags) return -EINVAL; =20 --=20 2.42.0.283.g2d96d420d3-goog