kernel/linux.git/include/linux/efi.h, branch v6.12.80

efi: Avoid cold plugged memory for placing the kernel

2025-02-21T13:01:34+00:00

commit ba69e0750b0362870294adab09339a0c39c3beaf upstream. UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory regions that are 'cold plugged' at boot, i.e., hot pluggable memory that is available from early boot, and described as system RAM by the firmware. Existing loaders and EFI applications running in the boot context will happily use this memory for allocating data structures that cannot be freed or moved at runtime, and this prevents the memory from being unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute should be tested, and memory annotated as such should be avoided for such allocations. In the EFI stub, there are a couple of occurrences where, instead of the high-level AllocatePages() UEFI boot service, a low-level code sequence is used that traverses the EFI memory map and carves out the requested number of pages from a free region. This is needed, e.g., for allocating as low as possible, or for allocating pages at random. While AllocatePages() should presumably avoid special purpose memory and cold plugged regions, this manual approach needs to incorporate this logic itself, in order to prevent the kernel itself from ending up in a hot unpluggable region, preventing it from being unplugged. So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it where appropriate. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

efi: Remove unused declaration efi_initialize_iomem_resources()

2024-08-27T10:22:18+00:00

Since commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"), this is not used anymore. Signed-off-by: Yue Haibing Signed-off-by: Ard Biesheuvel

efi: Replace efi_memory_attributes_table_t 0-sized array with flexible array

2024-07-12T08:06:01+00:00

While efi_memory_attributes_table_t::entry isn't used directly as an array, it is used as a base for pointer arithmetic. The type is wrong as it's not technically an array of efi_memory_desc_t's; they could be larger. Regardless, leave the type unchanged and remove the old style "0" array size. Additionally replace the open-coded entry offset code with the existing efi_memdesc_ptr() helper. Signed-off-by: Kees Cook Signed-off-by: Ard Biesheuvel

efi: Rename efi_early_memdesc_ptr() to efi_memdesc_ptr()

2024-07-12T08:06:01+00:00

The "early" part of the helper's name isn't accurate[1]. Drop it in preparation for adding a new (not early) usage. Suggested-by: Ard Biesheuvel Link: https://lore.kernel.org/lkml/CAMj1kXEyDjH0uu3Z4eBesV3PEnKGi5ArXXMp7R-hn8HdRytiPg@mail.gmail.com [1] Signed-off-by: Kees Cook Signed-off-by: Ard Biesheuvel

x86/efistub: Call Apple set_os protocol on dual GPU Intel Macs

2024-07-08T08:17:45+00:00

0c18184de990 ("platform/x86: apple-gmux: support MMIO gmux on T2 Macs") brought support for T2 Macs in apple-gmux. But in order to use dual GPU, the integrated GPU has to be enabled. On such dual GPU EFI Macs, the EFI stub needs to report that it is booting macOS in order to prevent the firmware from disabling the iGPU. This patch is also applicable for some non T2 Intel Macs. Based on this patch for GRUB by Andreas Heider : https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html Credits also goto Kerem Karabay for helping porting the patch to the Linux kernel. Cc: Orlando Chamberlain Signed-off-by: Aditya Garg [ardb: limit scope using list of DMI matches provided by Lukas and Orlando] Reviewed-by: Lukas Wunner Tested-by: Aditya Garg Signed-off-by: Ard Biesheuvel

x86/efistub: Enable SMBIOS protocol handling for x86

2024-07-08T08:17:44+00:00

The smbios.c source file is not currently included in the x86 build, and before we can do so, it needs some tweaks to build correctly in combination with the EFI mixed mode support. Reviewed-by: Lukas Wunner Signed-off-by: Ard Biesheuvel

efi: Clear up misconceptions about a maximum variable name size

2024-04-13T08:33:02+00:00

The UEFI specification does not make any mention of a maximum variable name size, so the headers and implementation shouldn't claim that one exists either. Comments referring to this limit have been removed or rewritten, as this is an implementation detail local to the Linux kernel. Where appropriate, the magic value of 1024 has been replaced with EFI_VAR_NAME_LEN, as this is used for the efi_variable struct definition. This in itself does not change any behavior, but should serve as points of interest when making future changes in the same area. A related build-time check has been added to ensure that the special 512 byte sized buffer will not overflow with a potentially decreased EFI_VAR_NAME_LEN. Signed-off-by: Tim Schumacher Signed-off-by: Ard Biesheuvel

Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-03-15T00:43:30+00:00

Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...

efi/libstub: Add get_event_log() support for CC platforms

2024-03-09T10:37:17+00:00

To allow event log info access after boot, EFI boot stub extracts the event log information and installs it in an EFI configuration table. Currently, EFI boot stub only supports installation of event log only for TPM 1.2 and TPM 2.0 protocols. Extend the same support for CC protocol. Since CC platform also uses TCG2 format, reuse TPM2 support code as much as possible. Link: https://uefi.org/specs/UEFI/2.10/38_Confidential_Computing.html#efi-cc-measurement-protocol [1] Signed-off-by: Kuppuswamy Sathyanarayanan Link: https://lkml.kernel.org/r/0229a87e-fb19-4dad-99fc-4afd7ed4099a%40collabora.com [ardb: Split out final events table handling to avoid version confusion] Signed-off-by: Ard Biesheuvel

efi/libstub: Add Confidential Computing (CC) measurement typedefs

2024-03-09T10:36:56+00:00

If the virtual firmware implements TPM support, TCG2 protocol will be used for kernel measurements and event logging support. But in CC environment, not all platforms support or enable the TPM feature. UEFI specification [1] exposes protocol and interfaces used for kernel measurements in CC platforms without TPM support. More details about the EFI CC measurements and logging can be found in [1]. Link: https://uefi.org/specs/UEFI/2.10/38_Confidential_Computing.html#efi-cc-measurement-protocol [1] Signed-off-by: Kuppuswamy Sathyanarayanan [ardb: Drop code changes, keep typedefs and #define's only] Signed-off-by: Ard Biesheuvel