From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- fs/squashfs/inode.c | 456 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 456 insertions(+) create mode 100644 fs/squashfs/inode.c (limited to 'fs/squashfs/inode.c') diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c new file mode 100644 index 000000000..82b687414 --- /dev/null +++ b/fs/squashfs/inode.c @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 + * Phillip Lougher + * + * inode.c + */ + +/* + * This file implements code to create and read inodes from disk. + * + * Inodes in Squashfs are identified by a 48-bit inode which encodes the + * location of the compressed metadata block containing the inode, and the byte + * offset into that block where the inode is placed (). + * + * To maximise compression there are different inodes for each file type + * (regular file, directory, device, etc.), the inode contents and length + * varying with the type. + * + * To further maximise compression, two types of regular file inode and + * directory inode are defined: inodes optimised for frequently occurring + * regular files and directories, and extended types where extra + * information has to be stored. + */ + +#include +#include +#include +#include + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "xattr.h" + +/* + * Initialise VFS inode with the base inode information common to all + * Squashfs inode types. Sqsh_ino contains the unswapped base inode + * off disk. + */ +static int squashfs_new_inode(struct super_block *sb, struct inode *inode, + struct squashfs_base_inode *sqsh_ino) +{ + uid_t i_uid; + gid_t i_gid; + int err; + + inode->i_ino = le32_to_cpu(sqsh_ino->inode_number); + if (inode->i_ino == 0) + return -EINVAL; + + err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->uid), &i_uid); + if (err) + return err; + + err = squashfs_get_id(sb, le16_to_cpu(sqsh_ino->guid), &i_gid); + if (err) + return err; + + i_uid_write(inode, i_uid); + i_gid_write(inode, i_gid); + inode_set_mtime(inode, le32_to_cpu(sqsh_ino->mtime), 0); + inode_set_atime(inode, inode_get_mtime_sec(inode), 0); + inode_set_ctime(inode, inode_get_mtime_sec(inode), 0); + inode->i_mode = le16_to_cpu(sqsh_ino->mode); + inode->i_size = 0; + + /* File type must not be set at this moment, for it will later be set by the caller. */ + if (inode->i_mode & S_IFMT) + err = -EIO; + + return err; +} + + +struct inode *squashfs_iget(struct super_block *sb, long long ino, + unsigned int ino_number) +{ + struct inode *inode = iget_locked(sb, ino_number); + int err; + + TRACE("Entered squashfs_iget\n"); + + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode_state_read_once(inode) & I_NEW)) + return inode; + + err = squashfs_read_inode(inode, ino); + if (err) { + iget_failed(inode); + return ERR_PTR(err); + } + + unlock_new_inode(inode); + return inode; +} + + +/* + * Initialise VFS inode by reading inode from inode table (compressed + * metadata). The format and amount of data read depends on type. + */ +int squashfs_read_inode(struct inode *inode, long long ino) +{ + struct super_block *sb = inode->i_sb; + struct squashfs_sb_info *msblk = sb->s_fs_info; + u64 block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; + int err, type, offset = SQUASHFS_INODE_OFFSET(ino); + union squashfs_inode squashfs_ino; + struct squashfs_base_inode *sqshb_ino = &squashfs_ino.base; + int xattr_id = SQUASHFS_INVALID_XATTR; + + TRACE("Entered squashfs_read_inode\n"); + + /* + * Read inode base common to all inode types. + */ + err = squashfs_read_metadata(sb, sqshb_ino, &block, + &offset, sizeof(*sqshb_ino)); + if (err < 0) + goto failed_read; + + err = squashfs_new_inode(sb, inode, sqshb_ino); + if (err) + goto failed_read; + + block = SQUASHFS_INODE_BLK(ino) + msblk->inode_table; + offset = SQUASHFS_INODE_OFFSET(ino); + + type = le16_to_cpu(sqshb_ino->inode_type); + switch (type) { + case SQUASHFS_REG_TYPE: { + unsigned int frag_offset, frag; + int frag_size; + u64 frag_blk; + struct squashfs_reg_inode *sqsh_ino = &squashfs_ino.reg; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + inode->i_size = le32_to_cpu(sqsh_ino->file_size); + frag = le32_to_cpu(sqsh_ino->fragment); + if (frag != SQUASHFS_INVALID_FRAG) { + /* + * the file cannot have a fragment (tailend) and have a + * file size a multiple of the block size + */ + if ((inode->i_size & (msblk->block_size - 1)) == 0) { + err = -EINVAL; + goto failed_read; + } + frag_offset = le32_to_cpu(sqsh_ino->offset); + frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); + if (frag_size < 0) { + err = frag_size; + goto failed_read; + } + } else { + frag_blk = SQUASHFS_INVALID_BLK; + frag_size = 0; + frag_offset = 0; + } + + set_nlink(inode, 1); + inode->i_fop = &squashfs_file_operations; + inode->i_mode |= S_IFREG; + inode->i_blocks = ((inode->i_size - 1) >> 9) + 1; + squashfs_i(inode)->fragment_block = frag_blk; + squashfs_i(inode)->fragment_size = frag_size; + squashfs_i(inode)->fragment_offset = frag_offset; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->block_list_start = block; + squashfs_i(inode)->offset = offset; + squashfs_i(inode)->parent = 0; + inode->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, block_list_start " + "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), + offset, squashfs_i(inode)->start, block, offset); + break; + } + case SQUASHFS_LREG_TYPE: { + unsigned int frag_offset, frag; + int frag_size; + u64 frag_blk; + struct squashfs_lreg_inode *sqsh_ino = &squashfs_ino.lreg; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + inode->i_size = le64_to_cpu(sqsh_ino->file_size); + if (inode->i_size < 0) { + err = -EINVAL; + goto failed_read; + } + frag = le32_to_cpu(sqsh_ino->fragment); + if (frag != SQUASHFS_INVALID_FRAG) { + /* + * the file cannot have a fragment (tailend) and have a + * file size a multiple of the block size + */ + if ((inode->i_size & (msblk->block_size - 1)) == 0) { + err = -EINVAL; + goto failed_read; + } + frag_offset = le32_to_cpu(sqsh_ino->offset); + frag_size = squashfs_frag_lookup(sb, frag, &frag_blk); + if (frag_size < 0) { + err = frag_size; + goto failed_read; + } + } else { + frag_blk = SQUASHFS_INVALID_BLK; + frag_size = 0; + frag_offset = 0; + } + + xattr_id = le32_to_cpu(sqsh_ino->xattr); + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_op = &squashfs_inode_ops; + inode->i_fop = &squashfs_file_operations; + inode->i_mode |= S_IFREG; + inode->i_blocks = (inode->i_size - + le64_to_cpu(sqsh_ino->sparse) + 511) >> 9; + + squashfs_i(inode)->fragment_block = frag_blk; + squashfs_i(inode)->fragment_size = frag_size; + squashfs_i(inode)->fragment_offset = frag_offset; + squashfs_i(inode)->start = le64_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->block_list_start = block; + squashfs_i(inode)->offset = offset; + squashfs_i(inode)->parent = 0; + inode->i_data.a_ops = &squashfs_aops; + + TRACE("File inode %x:%x, start_block %llx, block_list_start " + "%llx, offset %x\n", SQUASHFS_INODE_BLK(ino), + offset, squashfs_i(inode)->start, block, offset); + break; + } + case SQUASHFS_DIR_TYPE: { + struct squashfs_dir_inode *sqsh_ino = &squashfs_ino.dir; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le16_to_cpu(sqsh_ino->file_size); + inode->i_op = &squashfs_dir_inode_ops; + inode->i_fop = &squashfs_dir_ops; + inode->i_mode |= S_IFDIR; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); + squashfs_i(inode)->dir_idx_cnt = 0; + squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); + + TRACE("Directory inode %x:%x, start_block %llx, offset %x\n", + SQUASHFS_INODE_BLK(ino), offset, + squashfs_i(inode)->start, + le16_to_cpu(sqsh_ino->offset)); + break; + } + case SQUASHFS_LDIR_TYPE: { + struct squashfs_ldir_inode *sqsh_ino = &squashfs_ino.ldir; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + xattr_id = le32_to_cpu(sqsh_ino->xattr); + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_size = le32_to_cpu(sqsh_ino->file_size); + inode->i_op = &squashfs_dir_inode_ops; + inode->i_fop = &squashfs_dir_ops; + inode->i_mode |= S_IFDIR; + squashfs_i(inode)->start = le32_to_cpu(sqsh_ino->start_block); + squashfs_i(inode)->offset = le16_to_cpu(sqsh_ino->offset); + squashfs_i(inode)->dir_idx_start = block; + squashfs_i(inode)->dir_idx_offset = offset; + squashfs_i(inode)->dir_idx_cnt = le16_to_cpu(sqsh_ino->i_count); + squashfs_i(inode)->parent = le32_to_cpu(sqsh_ino->parent_inode); + + TRACE("Long directory inode %x:%x, start_block %llx, offset " + "%x\n", SQUASHFS_INODE_BLK(ino), offset, + squashfs_i(inode)->start, + le16_to_cpu(sqsh_ino->offset)); + break; + } + case SQUASHFS_SYMLINK_TYPE: + case SQUASHFS_LSYMLINK_TYPE: { + struct squashfs_symlink_inode *sqsh_ino = &squashfs_ino.symlink; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + inode->i_size = le32_to_cpu(sqsh_ino->symlink_size); + if (inode->i_size > PAGE_SIZE) { + ERROR("Corrupted symlink\n"); + return -EINVAL; + } + + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + inode->i_op = &squashfs_symlink_inode_ops; + inode_nohighmem(inode); + inode->i_data.a_ops = &squashfs_symlink_aops; + inode->i_mode |= S_IFLNK; + squashfs_i(inode)->start = block; + squashfs_i(inode)->offset = offset; + squashfs_i(inode)->parent = 0; + + if (type == SQUASHFS_LSYMLINK_TYPE) { + __le32 xattr; + + err = squashfs_read_metadata(sb, NULL, &block, + &offset, inode->i_size); + if (err < 0) + goto failed_read; + err = squashfs_read_metadata(sb, &xattr, &block, + &offset, sizeof(xattr)); + if (err < 0) + goto failed_read; + xattr_id = le32_to_cpu(xattr); + } + + TRACE("Symbolic link inode %x:%x, start_block %llx, offset " + "%x\n", SQUASHFS_INODE_BLK(ino), offset, + block, offset); + break; + } + case SQUASHFS_BLKDEV_TYPE: + case SQUASHFS_CHRDEV_TYPE: { + struct squashfs_dev_inode *sqsh_ino = &squashfs_ino.dev; + unsigned int rdev; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_CHRDEV_TYPE) + inode->i_mode |= S_IFCHR; + else + inode->i_mode |= S_IFBLK; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + rdev = le32_to_cpu(sqsh_ino->rdev); + init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); + squashfs_i(inode)->parent = 0; + + TRACE("Device inode %x:%x, rdev %x\n", + SQUASHFS_INODE_BLK(ino), offset, rdev); + break; + } + case SQUASHFS_LBLKDEV_TYPE: + case SQUASHFS_LCHRDEV_TYPE: { + struct squashfs_ldev_inode *sqsh_ino = &squashfs_ino.ldev; + unsigned int rdev; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_LCHRDEV_TYPE) + inode->i_mode |= S_IFCHR; + else + inode->i_mode |= S_IFBLK; + xattr_id = le32_to_cpu(sqsh_ino->xattr); + inode->i_op = &squashfs_inode_ops; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + rdev = le32_to_cpu(sqsh_ino->rdev); + init_special_inode(inode, inode->i_mode, new_decode_dev(rdev)); + squashfs_i(inode)->parent = 0; + + TRACE("Device inode %x:%x, rdev %x\n", + SQUASHFS_INODE_BLK(ino), offset, rdev); + break; + } + case SQUASHFS_FIFO_TYPE: + case SQUASHFS_SOCKET_TYPE: { + struct squashfs_ipc_inode *sqsh_ino = &squashfs_ino.ipc; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_FIFO_TYPE) + inode->i_mode |= S_IFIFO; + else + inode->i_mode |= S_IFSOCK; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + init_special_inode(inode, inode->i_mode, 0); + squashfs_i(inode)->parent = 0; + break; + } + case SQUASHFS_LFIFO_TYPE: + case SQUASHFS_LSOCKET_TYPE: { + struct squashfs_lipc_inode *sqsh_ino = &squashfs_ino.lipc; + + err = squashfs_read_metadata(sb, sqsh_ino, &block, &offset, + sizeof(*sqsh_ino)); + if (err < 0) + goto failed_read; + + if (type == SQUASHFS_LFIFO_TYPE) + inode->i_mode |= S_IFIFO; + else + inode->i_mode |= S_IFSOCK; + xattr_id = le32_to_cpu(sqsh_ino->xattr); + inode->i_op = &squashfs_inode_ops; + set_nlink(inode, le32_to_cpu(sqsh_ino->nlink)); + init_special_inode(inode, inode->i_mode, 0); + squashfs_i(inode)->parent = 0; + break; + } + default: + ERROR("Unknown inode type %d in squashfs_iget!\n", type); + return -EINVAL; + } + + if (xattr_id != SQUASHFS_INVALID_XATTR && msblk->xattr_id_table) { + err = squashfs_xattr_lookup(sb, xattr_id, + &squashfs_i(inode)->xattr_count, + &squashfs_i(inode)->xattr_size, + &squashfs_i(inode)->xattr); + if (err < 0) + goto failed_read; + inode->i_blocks += ((squashfs_i(inode)->xattr_size - 1) >> 9) + + 1; + } else + squashfs_i(inode)->xattr_count = 0; + + return 0; + +failed_read: + ERROR("Unable to read inode 0x%llx\n", ino); + return err; +} + + +const struct inode_operations squashfs_inode_ops = { + .listxattr = squashfs_listxattr +}; + -- cgit v1.3.1