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2024-05-07btrfs: free PERTRANS at the end of cleanup_transaction()Boris Burkov
Some of the operations after the free might convert more PERTRANS metadata. Do the freeing as late as possible to eliminate a source of leaked PERTRANS metadata. This helps with the pass rate of generic/269 and generic/475. Reviewed-by: Qu Wenruo <qwu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: compression: migrate compression/decompression paths to foliosQu Wenruo
For both compression and decompression paths, we always require a "struct page **pages" and "unsigned long nr_pages", this involves quite some part of the btrfs compression paths: - All the compression entry points - compressed_bio structure This affects both compression and decompression. - async_extent structure Unfortunately with all those involved parts, there is no good way to split the conversion into smaller patches while still passing compiling. So do this in one big conversion in one go. Please note this is direct page->folio conversion, no change on the page sized folio requirement yet. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor style fixups ] Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: introduce btrfs_alloc_folio_array()Qu Wenruo
The new helper will do the same thing as btrfs_alloc_page_array(), but with folios. One extra difference is, there is no extra helper for bulk allocation, thus it may not be as efficient as the page version. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: migrate insert_inline_extent() to folio interfacesQu Wenruo
Since insert_inline_extent() now only accepts a single page, it's much easier to convert it to use folio interfaces. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: make insert_inline_extent() accept one page directlyQu Wenruo
Since our inline extent cannot accept anything larger than a sector, there is really no need to pass all the compressed pages to insert_inline_extent(). And just in case, expand the ASSERT()s to make sure we only try inline with compressed size no larger than sectorsize. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: compression: convert page allocation to folio interfacesQu Wenruo
Currently we have two wrappers to allocate and free a page for compression usage: - btrfs_alloc_compr_page() - btrfs_free_compr_page() The allocator would try to grab a page from the pool, and only allocate a new page if the pool is empty. The reclaimer would check if the pool is full, and if not full it would put the page into the pool. This patch converts both helpers to use folio interfaces, and allowing further conversion of compression path to folios. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: compression: add error handling for missed page cacheQu Wenruo
For all the supported compression algorithms, the compression path would always need to grab the page cache, then do the compression. Normally we would get a page reference without any problem, since the write path should have already locked the pages in the write range. For the sake of error handling, we should handle the page cache miss case. Adds a common wrapper, btrfs_compress_find_get_page(), which calls find_get_page(), and do the error handling along with an error message. Callers inside compression path would only need to call btrfs_compress_find_get_page(), and error out if it returned any error. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: stop locking the source extent range during reflinkFilipe Manana
Nowadays before starting a reflink operation we do this: 1) Take the VFS lock of the inodes in exclusive mode (a rw semaphore); 2) Take the mmap lock of the inodes (struct btrfs_inode::i_mmap_lock); 3) Flush all delalloc in the source and target ranges; 4) Wait for all ordered extents in the source and target ranges to complete; 5) Lock the source and destination ranges in the inodes' io trees. In step 5 we lock the source range because: 1) We needed to serialize against mmap writes, but that is not needed anymore because nowadays we do that through the inode's i_mmap_lock (step 2). This happens since commit 8c99516a8cdd ("btrfs: exclude mmaps while doing remap"); 2) To serialize against a concurrent relocation and avoid generating a delayed ref for an extent that was just dropped by relocation, see commit d8b552424210 ("Btrfs: fix race between reflink/dedupe and relocation"). Locking the source range however blocks any concurrent reads for that range and makes test case generic/733 fail. So instead of locking the source range during reflinks, make relocation read lock the inode's i_mmap_lock, so that it serializes with a concurrent reflink while still able to run concurrently with mmap writes and allow concurrent reads too. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: qgroup: delete unnecessary check in btrfs_qgroup_check_inherit()Dan Carpenter
This check "if (inherit->num_qgroups > PAGE_SIZE)" is confusing and unnecessary. The problem with the check is that static checkers flag it as a potential mixup of between units of bytes vs number of elements. Fortunately, the check can safely be deleted because the next check is correct and applies an even stricter limit: if (size != struct_size(inherit, qgroups, inherit->num_qgroups)) return -EINVAL; The "inherit" struct ends in a variable array of __u64 and "inherit->num_qgroups" is the number of elements in the array. At the start of the function we check that: if (size < sizeof(*inherit) || size > PAGE_SIZE) return -EINVAL; Thus, since we verify that the whole struct fits within one page, that means that the number of elements in the inherit->qgroups[] array must be less than PAGE_SIZE. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: convert put_file_data() to foliosGoldwyn Rodrigues
Use folio instead of page in put_file_data(). Add a warning in case higher order folio is found, this will be implemented in the future. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: convert relocate_one_page() to folios and renameGoldwyn Rodrigues
Convert page references to folios and call the respective folio functions. Since find_or_create_page() takes a mask argument, call __filemap_get_folio() instead of filemap_grab_folio(). The patch assumes folio size is PAGE_SIZE, add a warning in case it's a higher order that will be implemented in the future. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: page to folio conversion: prealloc_file_extent_cluster()Goldwyn Rodrigues
Convert usage of page to folio in prealloc_file_extent_cluster() Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_direct_write()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in prepare_pages()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_dirty_pages()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in create_reloc_inode()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in __btrfs_end_transaction()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in convert_extent_bit()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in __set_extent_bit()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_ioctl_snap_destroy()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_cont_expand()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_rmdir()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in btrfs_initxattrs()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: warn if EXTENT_BUFFER_UPTODATE is set while readingTavian Barnes
We recently tracked down a race condition that triggered a read for an extent buffer with EXTENT_BUFFER_UPTODATE already set. While this read was in progress, other concurrent readers would see the UPTODATE bit and return early as if the read was already complete, making accesses to the extent buffer conflict with the read operation that was overwriting it. Add a WARN_ON() to end_bbio_meta_read() for this situation to make similar races easier to spot in the future. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Tavian Barnes <tavianator@tavianator.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: add helper to clear EXTENT_BUFFER_READINGTavian Barnes
We are clearing the bit and waking up any waiters in two different places. Factor that code out into a static helper function. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Tavian Barnes <tavianator@tavianator.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: avoid pointless wake ups of drew lock readersFilipe Manana
When unlocking a write lock on a drew lock, at btrfs_drew_write_unlock(), it's pointless to wake up tasks waiting to acquire a read lock if we didn't decrement the 'writers' counter down to 0, since a read lock can only be acquired when the counter reaches a value of 0. Doing so is harmless from a functional point of view, but it's not efficient due to unnecessarily waking up tasks just for them to sleep again on the waitqueue. So change this to wake up readers only if we decremented the 'writers' counter to 0. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: remove pointless writepages callback wrapperFilipe Manana
There's no point in having a static writepages callback in inode.c that does nothing besides calling extent_writepages from extent_io.c. So just remove the callback at inode.c and rename extent_writepages() to btrfs_writepages(). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: remove pointless readahead callback wrapperFilipe Manana
There's no point in having a static readahead callback in inode.c that does nothing besides calling extent_readahead() from extent_io.c. So just remove the callback at inode.c and rename extent_readahead() to btrfs_readahead(). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: locking: rename __btrfs_tree_lock() and __btrfs_tree_read_lock()Filipe Manana
The __btrfs_tree_lock() and __btrfs_tree_read_lock() are using a naming with a double underscore prefix, which is specially not proper for exported functions. Remove the double underscore prefix from their name and add the "_nested" suffix. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: locking: inline btrfs_tree_lock() and btrfs_tree_read_lock()Filipe Manana
The functions btrfs_tree_lock() and btrfs_tree_read_lock() are very trivial so that can be made inline and avoid call overhead, as they are very often called inside critical sections (when searching a btree for example, attempting to lock a child node/leaf while holding a lock on the parent). So make them static inline, which even reduces the size of the btrfs module a little bit. Before this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1718786 156276 16920 1891982 1cde8e fs/btrfs/btrfs.ko After this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1718650 156260 16920 1891830 1cddf6 fs/btrfs/btrfs.ko Running fs_mark also showed a tiny improvement with this script: $ cat test.sh #!/bin/bash DEV=/dev/nullb0 MNT=/mnt/nullb0 FILES=100000 THREADS=$(nproc --all) echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor umount $DEV &> /dev/null mkfs.btrfs -f $DEV mount $DEV $MNT OPTS="-S 0 -L 5 -n $FILES -s 0 -t $THREADS -k" for ((i = 1; i <= $THREADS; i++)); do OPTS="$OPTS -d $MNT/d$i" done fs_mark $OPTS umount $MNT Before this change: FSUse% Count Size Files/sec App Overhead 10 1200000 0 180894.0 10705410 16 2400000 0 228211.4 10765738 23 3600000 0 215969.6 11011072 30 4800000 0 199077.1 11145587 46 6000000 0 176624.1 11658470 After this change: FSUse% Count Size Files/sec App Overhead 10 1200000 0 185312.3 10708377 16 2400000 0 229320.4 10858013 23 3600000 0 217958.7 11006167 30 4800000 0 205122.9 11112899 46 6000000 0 178039.1 11438852 Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: remove pointless BUG_ON() when creating snapshotFilipe Manana
When creating a snapshot we first check with btrfs_lookup_dir_item() if there is a name collision in the parent directory and then return an error if there's a collision. Then later on when trying to insert a dir item for the snapshot we BUG_ON() if the return value is -EEXIST or -EOVERFLOW: static noinline int create_pending_snapshot(...) { (...) /* check if there is a file/dir which has the same name. */ dir_item = btrfs_lookup_dir_item(...); (...) ret = btrfs_insert_dir_item(...); /* We have check then name at the beginning, so it is impossible. */ BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } (...) } It's impossible to get the -EEXIST because we previously checked for a potential collision with btrfs_lookup_dir_item() and we know that after that no one could have added a colliding name because at this point the transaction is in its critical section, state TRANS_STATE_COMMIT_DOING, so no one can join this transaction to add a colliding name and neither can anyone start a new transaction to do that. As for the -EOVERFLOW, that can't happen as long as we have the extended references feature enabled, which is a mkfs default for many years now. In either case, the BUG_ON() is excessive as we can properly deal with any error and can abort the transaction and jump to the 'fail' label, in which case we'll also get the useful stack trace (just like a BUG_ON()) from the abort if the error is either -EEXIST or -EOVERFLOW. So remove the BUG_ON(). Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07io_uring/io-wq: Use set_bit() and test_bit() at worker->flagsBreno Leitao
Utilize set_bit() and test_bit() on worker->flags within io_uring/io-wq to address potential data races. The structure io_worker->flags may be accessed through various data paths, leading to concurrency issues. When KCSAN is enabled, it reveals data races occurring in io_worker_handle_work and io_wq_activate_free_worker functions. BUG: KCSAN: data-race in io_worker_handle_work / io_wq_activate_free_worker write to 0xffff8885c4246404 of 4 bytes by task 49071 on cpu 28: io_worker_handle_work (io_uring/io-wq.c:434 io_uring/io-wq.c:569) io_wq_worker (io_uring/io-wq.c:?) <snip> read to 0xffff8885c4246404 of 4 bytes by task 49024 on cpu 5: io_wq_activate_free_worker (io_uring/io-wq.c:? io_uring/io-wq.c:285) io_wq_enqueue (io_uring/io-wq.c:947) io_queue_iowq (io_uring/io_uring.c:524) io_req_task_submit (io_uring/io_uring.c:1511) io_handle_tw_list (io_uring/io_uring.c:1198) <snip> Line numbers against commit 18daea77cca6 ("Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm"). These races involve writes and reads to the same memory location by different tasks running on different CPUs. To mitigate this, refactor the code to use atomic operations such as set_bit(), test_bit(), and clear_bit() instead of basic "and" and "or" operations. This ensures thread-safe manipulation of worker flags. Also, move `create_index` to avoid holes in the structure. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240507170002.2269003-1-leitao@debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-07kcsan, compiler_types: Introduce __data_racy type qualifierMarco Elver
Based on the discussion at [1], it would be helpful to mark certain variables as explicitly "data racy", which would result in KCSAN not reporting data races involving any accesses on such variables. To do that, introduce the __data_racy type qualifier: struct foo { ... int __data_racy bar; ... }; In KCSAN-kernels, __data_racy turns into volatile, which KCSAN already treats specially by considering them "marked". In non-KCSAN kernels the type qualifier turns into no-op. The generated code between KCSAN-instrumented kernels and non-KCSAN kernels is already huge (inserted calls into runtime for every memory access), so the extra generated code (if any) due to volatile for few such __data_racy variables are unlikely to have measurable impact on performance. Link: https://lore.kernel.org/all/CAHk-=wi3iondeh_9V2g3Qz5oHTRjLsOpoy83hb58MVh=nRZe0A@mail.gmail.com/ [1] Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Marco Elver <elver@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-05-07KVM: SEV: Allow per-guest configuration of GHCB protocol versionMichael Roth
The GHCB protocol version may be different from one guest to the next. Add a field to track it for each KVM instance and extend KVM_SEV_INIT2 to allow it to be configured by userspace. Now that all SEV-ES support for GHCB protocol version 2 is in place, go ahead and default to it when creating SEV-ES guests through the new KVM_SEV_INIT2 interface. Keep the older KVM_SEV_ES_INIT interface restricted to GHCB protocol version 1. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240501071048.2208265-5-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: SEV: Add GHCB handling for termination requestsMichael Roth
GHCB version 2 adds support for a GHCB-based termination request that a guest can issue when it reaches an error state and wishes to inform the hypervisor that it should be terminated. Implement support for that similarly to GHCB MSR-based termination requests that are already available to SEV-ES guests via earlier versions of the GHCB protocol. See 'Termination Request' in the 'Invoking VMGEXIT' section of the GHCB specification for more details. Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240501071048.2208265-4-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: SEV: Add GHCB handling for Hypervisor Feature Support requestsBrijesh Singh
Version 2 of the GHCB specification introduced advertisement of features that are supported by the Hypervisor. Now that KVM supports version 2 of the GHCB specification, bump the maximum supported protocol version. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240501071048.2208265-3-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: SEV: Add support to handle AP reset MSR protocolTom Lendacky
Add support for AP Reset Hold being invoked using the GHCB MSR protocol, available in version 2 of the GHCB specification. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240501071048.2208265-2-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86: Explicitly zero kvm_caps during vendor module loadSean Christopherson
Zero out all of kvm_caps when loading a new vendor module to ensure that KVM can't inadvertently rely on global initialization of a field, and add a comment above the definition of kvm_caps to call out that all fields needs to be explicitly computed during vendor module load. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-ID: <20240423165328.2853870-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86: Fully re-initialize supported_mce_cap on vendor module loadSean Christopherson
Effectively reset supported_mce_cap on vendor module load to ensure that capabilities aren't unintentionally preserved across module reload, e.g. if kvm-intel.ko added a module param to control LMCE support, or if someone somehow managed to load a vendor module that doesn't support LMCE after loading and unloading kvm-intel.ko. Practically speaking, this bug is a non-issue as kvm-intel.ko doesn't have a module param for LMCE, and there is no system in the world that supports both kvm-intel.ko and kvm-amd.ko. Fixes: c45dcc71b794 ("KVM: VMX: enable guest access to LMCE related MSRs") Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-ID: <20240423165328.2853870-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86: Fully re-initialize supported_vm_types on vendor module loadSean Christopherson
Recompute the entire set of supported VM types when a vendor module is loaded, as preserving supported_vm_types across vendor module unload and reload can result in VM types being incorrectly treated as supported. E.g. if a vendor module is loaded with TDP enabled, unloaded, and then reloaded with TDP disabled, KVM_X86_SW_PROTECTED_VM will be incorrectly retained. Ditto for SEV_VM and SEV_ES_VM and their respective module params in kvm-amd.ko. Fixes: 2a955c4db1dd ("KVM: x86: Add supported_vm_types to kvm_caps") Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-ID: <20240423165328.2853870-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07Merge tag 'kvm-riscv-6.10-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.10 - Support guest breakpoints using ebreak - Introduce per-VCPU mp_state_lock and reset_cntx_lock - Virtualize SBI PMU snapshot and counter overflow interrupts - New selftests for SBI PMU and Guest ebreak
2024-05-07Merge tag 'kvm-s390-master-6.9-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix for 6.9 Fix wild read on capability check.
2024-05-07drm/connector: Add \n to message about demoting connector force-probesDouglas Anderson
The debug print clearly lacks a \n at the end. Add it. Fixes: 8f86c82aba8b ("drm/connector: demote connector force-probes for non-master clients") Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com> Reviewed-by: Simon Ser <contact@emersion.fr> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240502153234.1.I2052f01c8d209d9ae9c300b87c6e4f60bd3cc99e@changeid
2024-05-07gpiolib: fix the speed of descriptor label setting with SRCUBartosz Golaszewski
Commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU") caused a massive drop in performance of requesting GPIO lines due to the call to synchronize_srcu() on each label change. Rework the code to not wait until all read-only users are done with reading the label but instead atomically replace the label pointer and schedule its release after all read-only critical sections are done. To that end wrap the descriptor label in a struct that also contains the rcu_head struct required for deferring tasks using call_srcu() and stop using kstrdup_const() as we're required to allocate memory anyway. Just allocate enough for the label string and rcu_head in one go. Reported-by: Neil Armstrong <neil.armstrong@linaro.org> Closes: https://lore.kernel.org/linux-gpio/CAMRc=Mfig2oooDQYTqo23W3PXSdzhVO4p=G4+P8y1ppBOrkrJQ@mail.gmail.com/ Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU") Suggested-by: "Paul E. McKenney" <paulmck@kernel.org> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD Acked-by: "Paul E. McKenney" <paulmck@kernel.org> Link: https://lore.kernel.org/r/20240507121346.16969-1-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-05-07KVM: x86/mmu: Sanity check that __kvm_faultin_pfn() doesn't create noslot pfnsSean Christopherson
WARN if __kvm_faultin_pfn() generates a "no slot" pfn, and gracefully handle the unexpected behavior instead of continuing on with dangerous state, e.g. tdp_mmu_map_handle_target_level() _only_ checks fault->slot, and so could install a bogus PFN into the guest. The existing code is functionally ok, because kvm_faultin_pfn() pre-checks all of the cases that result in KVM_PFN_NOSLOT, but it is unnecessarily unsafe as it relies on __gfn_to_pfn_memslot() getting the _exact_ same memslot, i.e. not a re-retrieved pointer with KVM_MEMSLOT_INVALID set. And checking only fault->slot would fall apart if KVM ever added a flag or condition that forced emulation, similar to how KVM handles writes to read-only memslots. Cc: David Matlack <dmatlack@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240228024147.41573-17-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error valuesSean Christopherson
Explicitly set "pfn" and "hva" to error values in kvm_mmu_do_page_fault() to harden KVM against using "uninitialized" values. In quotes because the fields are actually zero-initialized, and zero is a legal value for both page frame numbers and virtual addresses. E.g. failure to set "pfn" prior to creating an SPTE could result in KVM pointing at physical address '0', which is far less desirable than KVM generating a SPTE with reserved PA bits set and thus effectively killing the VM. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240228024147.41573-16-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86/mmu: Set kvm_page_fault.hva to KVM_HVA_ERR_BAD for "no slot" faultsSean Christopherson
Explicitly set fault->hva to KVM_HVA_ERR_BAD when handling a "no slot" fault to ensure that KVM doesn't use a bogus virtual address, e.g. if there *was* a slot but it's unusable (APIC access page), or if there really was no slot, in which case fault->hva will be '0' (which is a legal address for x86). Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240228024147.41573-15-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86/mmu: Handle no-slot faults at the beginning of kvm_faultin_pfn()Sean Christopherson
Handle the "no memslot" case at the beginning of kvm_faultin_pfn(), just after the private versus shared check, so that there's no need to repeatedly query whether or not a slot exists. This also makes it more obvious that, except for private vs. shared attributes, the process of faulting in a pfn simply doesn't apply to gfns without a slot. Opportunistically stuff @fault's metadata in kvm_handle_noslot_fault() so that it doesn't need to be duplicated in all paths that invoke kvm_handle_noslot_fault(), and to minimize the probability of not stuffing the right fields. Leave the existing handle behind, but convert it to a WARN, to guard against __kvm_faultin_pfn() unexpectedly nullifying fault->slot. Cc: David Matlack <dmatlack@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240228024147.41573-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86/mmu: Move slot checks from __kvm_faultin_pfn() to kvm_faultin_pfn()Sean Christopherson
Move the checks related to the validity of an access to a memslot from the inner __kvm_faultin_pfn() to its sole caller, kvm_faultin_pfn(). This allows emulating accesses to the APIC access page, which don't need to resolve a pfn, even if there is a relevant in-progress mmu_notifier invalidation. Ditto for accesses to KVM internal memslots from L2, which KVM also treats as emulated MMIO. More importantly, this will allow for future cleanup by having the "no memslot" case bail from kvm_faultin_pfn() very early on. Go to rather extreme and gross lengths to make the change a glorified nop, e.g. call into __kvm_faultin_pfn() even when there is no slot, as the related code is very subtle. E.g. fault->slot can be nullified if it points at the APIC access page, some flows in KVM x86 expect fault->pfn to be KVM_PFN_NOSLOT, while others check only fault->slot, etc. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Message-ID: <20240228024147.41573-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-07KVM: x86/mmu: Explicitly disallow private accesses to emulated MMIOSean Christopherson
Explicitly detect and disallow private accesses to emulated MMIO in kvm_handle_noslot_fault() instead of relying on kvm_faultin_pfn_private() to perform the check. This will allow the page fault path to go straight to kvm_handle_noslot_fault() without bouncing through __kvm_faultin_pfn(). Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240228024147.41573-12-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>