kernel.git/arch/x86/boot/compressed, branch linux-6.15.y

x86/boot/sev: Support memory acceptance in the EFI stub under SVSM

2025-05-04T06:20:27Z

Commit: d54d610243a4 ("x86/boot/sev: Avoid shared GHCB page for early memory acceptance") provided a fix for SEV-SNP memory acceptance from the EFI stub when running at VMPL #0. However, that fix was insufficient for SVSM SEV-SNP guests running at VMPL >0, as those rely on a SVSM calling area, which is a shared buffer whose address is programmed into a SEV-SNP MSR, and the SEV init code that sets up this calling area executes much later during the boot. Given that booting via the EFI stub at VMPL >0 implies that the firmware has configured this calling area already, reuse it for performing memory acceptance in the EFI stub. Fixes: fcd042e86422 ("x86/sev: Perform PVALIDATE using the SVSM when not at VMPL0") Tested-by: Tom Lendacky Co-developed-by: Tom Lendacky Signed-off-by: Tom Lendacky Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: Cc: Dionna Amalie Glaze Cc: Kevin Loughlin Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20250428174322.2780170-2-ardb+git@google.com

x86/boot/sev: Avoid shared GHCB page for early memory acceptance

2025-04-18T12:30:30Z

Communicating with the hypervisor using the shared GHCB page requires clearing the C bit in the mapping of that page. When executing in the context of the EFI boot services, the page tables are owned by the firmware, and this manipulation is not possible. So switch to a different API for accepting memory in SEV-SNP guests, one which is actually supported at the point during boot where the EFI stub may need to accept memory, but the SEV-SNP init code has not executed yet. For simplicity, also switch the memory acceptance carried out by the decompressor when not booting via EFI - this only involves the allocation for the decompressed kernel, and is generally only called after kexec, as normal boot will jump straight into the kernel from the EFI stub. Fixes: 6c3211796326 ("x86/sev: Add SNP-specific unaccepted memory support") Tested-by: Tom Lendacky Co-developed-by: Tom Lendacky Signed-off-by: Tom Lendacky Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: Cc: Dionna Amalie Glaze Cc: Kevin Loughlin Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20250404082921.2767593-8-ardb+git@google.com # discussion thread #1 Link: https://lore.kernel.org/r/20250410132850.3708703-2-ardb+git@google.com # discussion thread #2 Link: https://lore.kernel.org/r/20250417202120.1002102-2-ardb+git@google.com # final submission

Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2025-04-05T22:46:50Z

Pull Kbuild updates from Masahiro Yamada: - Improve performance in gendwarfksyms - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS - Support CONFIG_HEADERS_INSTALL for ARCH=um - Use more relative paths to sources files for better reproducibility - Support the loong64 Debian architecture - Add Kbuild bash completion - Introduce intermediate vmlinux.unstripped for architectures that need static relocations to be stripped from the final vmlinux - Fix versioning in Debian packages for -rc releases - Treat missing MODULE_DESCRIPTION() as an error - Convert Nios2 Makefiles to use the generic rule for built-in DTB - Add debuginfo support to the RPM package * tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: rpm-pkg: build a debuginfo RPM kconfig: merge_config: use an empty file as initfile nios2: migrate to the generic rule for built-in DTB rust: kbuild: skip `--remap-path-prefix` for `rustdoc` kbuild: pacman-pkg: hardcode module installation path kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally modpost: require a MODULE_DESCRIPTION() kbuild: make all file references relative to source root x86: drop unnecessary prefix map configuration kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS kbuild: Add a help message for "headers" kbuild: deb-pkg: remove "version" variable in mkdebian kbuild: deb-pkg: fix versioning for -rc releases Documentation/kbuild: Fix indentation in modules.rst example x86: Get rid of Makefile.postlink kbuild: Create intermediate vmlinux build with relocations preserved kbuild: Introduce Kconfig symbol for linking vmlinux with relocations kbuild: link-vmlinux.sh: Make output file name configurable kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y Revert "kheaders: Ignore silly-rename files" ...

Merge tag 'efi-next-for-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

2025-03-29T18:36:19Z

Pull EFI updates from Ard Biesheuvel: - Decouple mixed mode startup code from the traditional x86 decompressor - Revert zero-length file hack in efivarfs - Prevent EFI zboot from using the CopyMem/SetMem boot services after ExitBootServices() - Update EFI zboot to use the ZLIB/ZSTD library interfaces directly * tag 'efi-next-for-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi/libstub: Avoid legacy decompressor zlib/zstd wrappers efi/libstub: Avoid CopyMem/SetMem EFI services after ExitBootServices efi: efibc: change kmalloc(size * count, ...) to kmalloc_array() efivarfs: Revert "allow creation of zero length files" x86/efi/mixed: Move mixed mode startup code into libstub x86/efi/mixed: Simplify and document thunking logic x86/efi/mixed: Remove dependency on legacy startup_32 code x86/efi/mixed: Set up 1:1 mapping of lower 4GiB in the stub x86/efi/mixed: Factor out and clean up long mode entry x86/efi/mixed: Check CPU compatibility without relying on verify_cpu() x86/efistub: Merge PE and handover entrypoints

Merge tag 'x86-boot-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-03-25T05:25:21Z

Pull x86 boot code updates from Ingo Molnar: - Memblock setup and other early boot code cleanups (Mike Rapoport) - Export e820_table_kexec[] to sysfs (Dave Young) - Baby steps of adding relocate_kernel() debugging support (David Woodhouse) - Replace open-coded parity calculation with parity8() (Kuan-Wei Chiu) - Move the LA57 trampoline to separate source file (Ard Biesheuvel) - Misc micro-optimizations (Uros Bizjak) - Drop obsolete E820_TYPE_RESERVED_KERN and related code (Mike Rapoport) * tag 'x86-boot-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kexec: Add relocate_kernel() debugging support: Load a GDT x86/boot: Move the LA57 trampoline to separate source file x86/boot: Do not test if AC and ID eflags are changeable on x86_64 x86/bootflag: Replace open-coded parity calculation with parity8() x86/bootflag: Micro-optimize sbf_write() x86/boot: Add missing has_cpuflag() prototype x86/kexec: Export e820_table_kexec[] to sysfs x86/boot: Change some static bootflag functions to bool x86/e820: Drop obsolete E820_TYPE_RESERVED_KERN and related code x86/boot: Split parsing of boot_params into the parse_boot_params() helper function x86/boot: Split kernel resources setup into the setup_kernel_resources() helper function x86/boot: Move setting of memblock parameters to e820__memblock_setup()

Merge tag 'x86-build-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-03-25T05:23:23Z

Pull x86 build updates from Ingo Molnar: - Drop CRC-32 checksum and the build tool that generates it (Ard Biesheuvel) - Fix broken copy command in genimage.sh when making isoimage (Nir Lichtman) * tag 'x86-build-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Add back some padding for the CRC-32 checksum x86/boot: Drop CRC-32 checksum and the build tool that generates it x86/build: Fix broken copy command in genimage.sh when making isoimage

x86: drop unnecessary prefix map configuration

2025-03-22T14:50:58Z

The toplevel Makefile already provides -fmacro-prefix-map as part of KBUILD_CPPFLAGS. In contrast to the KBUILD_CFLAGS and KBUILD_AFLAGS variables, KBUILD_CPPFLAGS is not redefined in the architecture specific Makefiles. Therefore the toplevel KBUILD_CPPFLAGS do apply just fine, to both C and ASM sources. The custom configuration was necessary when it was added in commit 9e2276fa6eb3 ("arch/x86/boot: Use prefix map to avoid embedded paths") but has since become unnecessary in commit a716bd743210 ("kbuild: use -fmacro-prefix-map for .S sources"). Drop the now unnecessary custom prefix map configuration. Signed-off-by: Thomas Weißschuh Signed-off-by: Masahiro Yamada

Merge tag 'v6.14-rc7' into x86/core, to pick up fixes

2025-03-19T10:03:06Z

Signed-off-by: Ingo Molnar

x86: Get rid of Makefile.postlink

2025-03-16T15:29:50Z

Instead of generating the vmlinux.relocs file (needed by the decompressor build to construct the KASLR relocation tables) as a vmlinux postlink step, which is dubious because it depends on data that is stripped from vmlinux before the build completes, generate it from vmlinux.unstripped, which has been introduced specifically for this purpose. This ensures that each artifact is rebuilt as needed, rather than as a side effect of another build rule. This effectively reverts commit 9d9173e9ceb6 ("x86/build: Avoid relocation information in final vmlinux") Signed-off-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada

x86/boot: Move the LA57 trampoline to separate source file

2025-03-13T17:12:38Z

To permit the EFI stub to call this code even when building the kernel without the legacy decompressor, move the trampoline out of the latter's startup code. This is part of an ongoing WIP effort on my part to make the existing, generic EFI zboot format work on x86 as well. No functional change intended. Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250313120324.1095968-2-ardb+git@google.com