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2023-10-25x86/sev: Check for user-space IOIO pointing to kernel spaceJoerg Roedel
Upstream commit: 63e44bc52047f182601e7817da969a105aa1f721 Check the memory operand of INS/OUTS before emulating the instruction. The #VC exception can get raised from user-space, but the memory operand can be manipulated to access kernel memory before the emulation actually begins and after the exception handler has run. [ bp: Massage commit message. ] Fixes: 597cfe48212a ("x86/boot/compressed/64: Setup a GHCB-based VC Exception handler") Reported-by: Tom Dohrmann <erbse.13@gmx.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-25x86/sev: Check IOBM for IOIO exceptions from user-spaceJoerg Roedel
Upstream commit: b9cb9c45583b911e0db71d09caa6b56469eb2bdf Check the IO permission bitmap (if present) before emulating IOIO #VC exceptions for user-space. These permissions are checked by hardware already before the #VC is raised, but due to the VC-handler decoding race it needs to be checked again in software. Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: Tom Dohrmann <erbse.13@gmx.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Dohrmann <erbse.13@gmx.de> Cc: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23x86/boot/compressed: Reserve more memory for page tablesKirill A. Shutemov
[ Upstream commit f530ee95b72e77b09c141c4b1a4b94d1199ffbd9 ] The decompressor has a hard limit on the number of page tables it can allocate. This limit is defined at compile-time and will cause boot failure if it is reached. The kernel is very strict and calculates the limit precisely for the worst-case scenario based on the current configuration. However, it is easy to forget to adjust the limit when a new use-case arises. The worst-case scenario is rarely encountered during sanity checks. In the case of enabling 5-level paging, a use-case was overlooked. The limit needs to be increased by one to accommodate the additional level. This oversight went unnoticed until Aaron attempted to run the kernel via kexec with 5-level paging and unaccepted memory enabled. Update wost-case calculations to include 5-level paging. To address this issue, let's allocate some extra space for page tables. 128K should be sufficient for any use-case. The logic can be simplified by using a single value for all kernel configurations. [ Also add a warning, should this memory run low - by Dave Hansen. ] Fixes: 34bbb0009f3b ("x86/boot/compressed: Enable 5-level paging during decompression stage") Reported-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915070221.10266-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13x86/decompressor: Don't rely on upper 32 bits of GPRs being preservedArd Biesheuvel
[ Upstream commit 264b82fdb4989cf6a44a2bcd0c6ea05e8026b2ac ] The 4-to-5 level mode switch trampoline disables long mode and paging in order to be able to flick the LA57 bit. According to section 3.4.1.1 of the x86 architecture manual [0], 64-bit GPRs might not retain the upper 32 bits of their contents across such a mode switch. Given that RBP, RBX and RSI are live at this point, preserve them on the stack, along with the return address that might be above 4G as well. [0] Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 1: Basic Architecture "Because the upper 32 bits of 64-bit general-purpose registers are undefined in 32-bit modes, the upper 32 bits of any general-purpose register are not preserved when switching from 64-bit mode to a 32-bit mode (to protected mode or compatibility mode). Software must not depend on these bits to maintain a value after a 64-bit to 32-bit mode switch." Fixes: 194a9749c73d650c ("x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230807162720.545787-2-ardb@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-16x86/sev: Do not try to parse for the CC blob on non-AMD hardwareBorislav Petkov (AMD)
commit bee6cf1a80b54548a039e224c651bb15b644a480 upstream. Tao Liu reported a boot hang on an Intel Atom machine due to an unmapped EFI config table. The reason being that the CC blob which contains the CPUID page for AMD SNP guests is parsed for before even checking whether the machine runs on AMD hardware. Usually that's not a problem on !AMD hw - it simply won't find the CC blob's GUID and return. However, if any parts of the config table pointers array is not mapped, the kernel will #PF very early in the decompressor stage without any opportunity to recover. Therefore, do a superficial CPUID check before poking for the CC blob. This will fix the current issue on real hardware. It would also work as a guest on a non-lying hypervisor. For the lying hypervisor, the check is done again, *after* parsing the CC blob as the real CPUID page will be present then. Clear the #VC handler in case SEV-{ES,SNP} hasn't been detected, as a precaution. Fixes: c01fce9cef84 ("x86/compressed: Add SEV-SNP feature detection/setup") Reported-by: Tao Liu <ltao@redhat.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Tested-by: Tao Liu <ltao@redhat.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20230601072043.24439-1-ltao@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21x86/boot/compressed: prefer cc-option for CFLAGS additionsNick Desaulniers
commit 994f5f7816ff963f49269cfc97f63cb2e4edb84f upstream. as-option tests new options using KBUILD_CFLAGS, which causes problems when using as-option to update KBUILD_AFLAGS because many compiler options are not valid assembler options. This will be fixed in a follow up patch. Before doing so, move the assembler test for -Wa,-mrelax-relocations=no from using as-option to cc-option. Link: https://lore.kernel.org/llvm/CAK7LNATcHt7GcXZ=jMszyH=+M_LC9Qr6yeAGRCBbE6xriLxtUQ@mail.gmail.com/ Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01x86/sev: Add SEV-SNP guest feature negotiation supportNikunj A Dadhania
commit 8c29f016540532582721cec1dbf6d144873433ba upstream. The hypervisor can enable various new features (SEV_FEATURES[1:63]) and start a SNP guest. Some of these features need guest side implementation. If any of these features are enabled without it, the behavior of the SNP guest will be undefined. It may fail booting in a non-obvious way making it difficult to debug. Instead of allowing the guest to continue and have it fail randomly later, detect this early and fail gracefully. The SEV_STATUS MSR indicates features which the hypervisor has enabled. While booting, SNP guests should ascertain that all the enabled features have guest side implementation. In case a feature is not implemented in the guest, the guest terminates booting with GHCB protocol Non-Automatic Exit(NAE) termination request event, see "SEV-ES Guest-Hypervisor Communication Block Standardization" document (currently at https://developer.amd.com/wp-content/resources/56421.pdf), section "Termination Request". Populate SW_EXITINFO2 with mask of unsupported features that the hypervisor can easily report to the user. More details in the AMD64 APM Vol 2, Section "SEV_STATUS MSR". [ bp: - Massage. - Move snp_check_features() call to C code. Note: the CC:stable@ aspect here is to be able to protect older, stable kernels when running on newer hypervisors. Or not "running" but fail reliably and in a well-defined manner instead of randomly. ] Fixes: cbd3d4f7c4e5 ("x86/sev: Check SEV-SNP features support") Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20230118061943.534309-1-nikunj@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18x86/boot: Avoid using Intel mnemonics in AT&T syntax asmPeter Zijlstra
commit 7c6dd961d0c8e7e8f9fdc65071fb09ece702e18d upstream. With 'GNU assembler (GNU Binutils for Debian) 2.39.90.20221231' the build now reports: arch/x86/realmode/rm/../../boot/bioscall.S: Assembler messages: arch/x86/realmode/rm/../../boot/bioscall.S:35: Warning: found `movsd'; assuming `movsl' was meant arch/x86/realmode/rm/../../boot/bioscall.S:70: Warning: found `movsd'; assuming `movsl' was meant arch/x86/boot/bioscall.S: Assembler messages: arch/x86/boot/bioscall.S:35: Warning: found `movsd'; assuming `movsl' was meant arch/x86/boot/bioscall.S:70: Warning: found `movsd'; assuming `movsl' was meant Which is due to: PR gas/29525 Note that with the dropped CMPSD and MOVSD Intel Syntax string insn templates taking operands, mixed IsString/non-IsString template groups (with memory operands) cannot occur anymore. With that maybe_adjust_templates() becomes unnecessary (and is hence being removed). More details: https://sourceware.org/bugzilla/show_bug.cgi?id=29525 Borislav Petkov further explains: " the particular problem here is is that the 'd' suffix is "conflicting" in the sense that you can have SSE mnemonics like movsD %xmm... and the same thing also for string ops (which is the case here) so apparently the agreement in binutils land is to use the always accepted suffixes 'l' or 'q' and phase out 'd' slowly... " Fixes: 7a734e7dd93b ("x86, setup: "glove box" BIOS calls -- infrastructure") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/Y71I3Ex2pvIxMpsP@hirez.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-24kbuild: fix "cat: .version: No such file or directory"Masahiro Yamada
Since commit 2df8220cc511 ("kbuild: build init/built-in.a just once"), the .version file is not touched at all when KBUILD_BUILD_VERSION is given. If KBUILD_BUILD_VERSION is specified and the .version file is missing (for example right after 'make mrproper'), "No such file or director" is shown. Even if the .version exists, it is irrelevant to the version of the current build. $ make -j$(nproc) KBUILD_BUILD_VERSION=100 mrproper defconfig all [ snip ] BUILD arch/x86/boot/bzImage cat: .version: No such file or directory Kernel: arch/x86/boot/bzImage is ready (#) Show KBUILD_BUILD_VERSION if it is given. Fixes: 2df8220cc511 ("kbuild: build init/built-in.a just once") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Merge tag 'kbuild-v6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...
2022-10-04Merge tag 'x86_cleanups_for_v6.1_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: - The usual round of smaller fixes and cleanups all over the tree * tag 'x86_cleanups_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Include the header of init_ia32_feat_ctl()'s prototype x86/uaccess: Improve __try_cmpxchg64_user_asm() for x86_32 x86: Fix various duplicate-word comment typos x86/boot: Remove superfluous type casting from arch/x86/boot/bitops.h
2022-10-03x86: kmsan: disable instrumentation of unsupported codeAlexander Potapenko
Instrumenting some files with KMSAN will result in kernel being unable to link, boot or crashing at runtime for various reasons (e.g. infinite recursion caused by instrumentation hooks calling instrumented code again). Completely omit KMSAN instrumentation in the following places: - arch/x86/boot and arch/x86/realmode/rm, as KMSAN doesn't work for i386; - arch/x86/entry/vdso, which isn't linked with KMSAN runtime; - three files in arch/x86/kernel - boot problems; - arch/x86/mm/cpu_entry_area.c - recursion. Link: https://lkml.kernel.org/r/20220915150417.722975-33-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-29kbuild: build init/built-in.a just onceMasahiro Yamada
Kbuild builds init/built-in.a twice; first during the ordinary directory descending, second from scripts/link-vmlinux.sh. We do this because UTS_VERSION contains the build version and the timestamp. We cannot update it during the normal directory traversal since we do not yet know if we need to update vmlinux. UTS_VERSION is temporarily calculated, but omitted from the update check. Otherwise, vmlinux would be rebuilt every time. When Kbuild results in running link-vmlinux.sh, it increments the version number in the .version file and takes the timestamp at that time to really fix UTS_VERSION. However, updating the same file twice is a footgun. To avoid nasty timestamp issues, all build artifacts that depend on init/built-in.a are atomically generated in link-vmlinux.sh, where some of them do not need rebuilding. To fix this issue, this commit changes as follows: [1] Split UTS_VERSION out to include/generated/utsversion.h from include/generated/compile.h include/generated/utsversion.h is generated just before the vmlinux link. It is generated under include/generated/ because some decompressors (s390, x86) use UTS_VERSION. [2] Split init_uts_ns and linux_banner out to init/version-timestamp.c from init/version.c init_uts_ns and linux_banner contain UTS_VERSION. During the ordinary directory descending, they are compiled with __weak and used to determine if vmlinux needs relinking. Just before the vmlinux link, they are compiled without __weak to embed the real version and timestamp. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-08-24x86/boot: Don't propagate uninitialized boot_params->cc_blob_addressMichael Roth
In some cases, bootloaders will leave boot_params->cc_blob_address uninitialized rather than zeroing it out. This field is only meant to be set by the boot/compressed kernel in order to pass information to the uncompressed kernel when SEV-SNP support is enabled. Therefore, there are no cases where the bootloader-provided values should be treated as anything other than garbage. Otherwise, the uncompressed kernel may attempt to access this bogus address, leading to a crash during early boot. Normally, sanitize_boot_params() would be used to clear out such fields but that happens too late: sev_enable() may have already initialized it to a valid value that should not be zeroed out. Instead, have sev_enable() zero it out unconditionally beforehand. Also ensure this happens for !CONFIG_AMD_MEM_ENCRYPT as well by also including this handling in the sev_enable() stub function. [ bp: Massage commit message and comments. ] Fixes: b190a043c49a ("x86/sev: Add SEV-SNP feature detection/setup") Reported-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com> Reported-by: watnuss@gmx.de Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=216387 Link: https://lore.kernel.org/r/20220823160734.89036-1-michael.roth@amd.com
2022-08-15x86/boot: Remove superfluous type casting from arch/x86/boot/bitops.hLi kunyu
'const void *' will auto-type-convert to just about any other const pointer type, no need to force it. [ mingo: Rewrote the changelog. ] Signed-off-by: Li kunyu <kunyu@nfschina.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220725042358.3377-1-kunyu@nfschina.com
2022-08-10x86: link vdso and boot with -z noexecstack --no-warn-rwx-segmentsNick Desaulniers
Users of GNU ld (BFD) from binutils 2.39+ will observe multiple instances of a new warning when linking kernels in the form: ld: warning: arch/x86/boot/pmjump.o: missing .note.GNU-stack section implies executable stack ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker ld: warning: arch/x86/boot/compressed/vmlinux has a LOAD segment with RWX permissions Generally, we would like to avoid the stack being executable. Because there could be a need for the stack to be executable, assembler sources have to opt-in to this security feature via explicit creation of the .note.GNU-stack feature (which compilers create by default) or command line flag --noexecstack. Or we can simply tell the linker the production of such sections is irrelevant and to link the stack as --noexecstack. LLVM's LLD linker defaults to -z noexecstack, so this flag isn't strictly necessary when linking with LLD, only BFD, but it doesn't hurt to be explicit here for all linkers IMO. --no-warn-rwx-segments is currently BFD specific and only available in the current latest release, so it's wrapped in an ld-option check. While the kernel makes extensive usage of ELF sections, it doesn't use permissions from ELF segments. Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/ Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107 Link: https://github.com/llvm/llvm-project/issues/57009 Reported-and-tested-by: Jens Axboe <axboe@kernel.dk> Suggested-by: Fangrui Song <maskray@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-06x86/compressed/64: Add identity mappings for setup_data entriesMichael Roth
The decompressed kernel initially relies on the identity map set up by the boot/compressed kernel for accessing things like boot_params. With the recent introduction of SEV-SNP support, the decompressed kernel also needs to access the setup_data entries pointed to by boot_params->hdr.setup_data. This can lead to a crash in the kexec kernel during early boot due to these entries not currently being included in the initial identity map, see thread at Link below. Include mappings for the setup_data entries in the initial identity map. [ bp: Massage commit message and use a helper var for better readability. ] Fixes: b190a043c49a ("x86/sev: Add SEV-SNP feature detection/setup") Reported-by: Jun'ichi Nomura <junichi.nomura@nec.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/TYCPR01MB694815CD815E98945F63C99183B49@TYCPR01MB6948.jpnprd01.prod.outlook.com
2022-06-03Merge tag 'efi-next-for-v5.19-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull more EFI updates from Ard Biesheuvel: "Follow-up tweaks for EFI changes - they mostly address issues introduced this merge window, except for Heinrich's patch: - fix new DXE service invocations for mixed mode - use correct Kconfig symbol when setting PE header flag - clean up the drivers/firmware/efi Kconfig dependencies so that features that depend on CONFIG_EFI are hidden from the UI when the symbol is not enabled. Also included is a RISC-V bugfix from Heinrich to avoid read-write mappings of read-only firmware regions in the EFI page tables" * tag 'efi-next-for-v5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: clean up Kconfig dependencies on CONFIG_EFI efi/x86: libstub: Make DXE calls mixed mode safe efi: x86: Fix config name for setting the NX-compatibility flag in the PE header riscv: read-only pages should not be writable
2022-06-01efi: x86: Fix config name for setting the NX-compatibility flag in the PE headerLukas Bulwahn
Commit 21b68da7bf4a ("efi: x86: Set the NX-compatibility flag in the PE header") intends to set the compatibility flag, i.e., IMAGE_DLL_CHARACTERISTICS_NX_COMPAT, but this ifdef is actually dead as the CONFIG_DXE_MEM_ATTRIBUTES Kconfig option does not exist. The config is actually called EFI_DXE_MEM_ATTRIBUTES. Adjust the ifdef to use the intended config name. The issue was identified with ./scripts/checkkconfigsymbols.py. Fixes: 21b68da7bf4a ("efi: x86: Set the NX-compatibility flag in the PE header") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20220601115043.7678-1-lukas.bulwahn@gmail.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-26Merge tag 'kbuild-v5.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add HOSTPKG_CONFIG env variable to allow users to override pkg-config - Support W=e as a shorthand for KCFLAGS=-Werror - Fix CONFIG_IKHEADERS build to support toybox cpio - Add scripts/dummy-tools/pahole to ease distro packagers' life - Suppress false-positive warnings from checksyscalls.sh for W=2 build - Factor out the common code of arch/*/boot/install.sh into scripts/install.sh - Support 'kernel-install' tool in scripts/prune-kernel - Refactor module-versioning to link the symbol versions at the final link of vmlinux and modules - Remove CONFIG_MODULE_REL_CRCS because module-versioning now works in an arch-agnostic way - Refactor modpost, Makefiles * tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (56 commits) genksyms: adjust the output format to modpost kbuild: stop merging *.symversions kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS modpost: extract symbol versions from *.cmd files modpost: add sym_find_with_module() helper modpost: change the license of EXPORT_SYMBOL to bool type modpost: remove left-over cross_compile declaration kbuild: record symbol versions in *.cmd files kbuild: generate a list of objects in vmlinux modpost: move *.mod.c generation to write_mod_c_files() modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header scripts/prune-kernel: Use kernel-install if available kbuild: factor out the common installation code into scripts/install.sh modpost: split new_symbol() to symbol allocation and hash table addition modpost: make sym_add_exported() always allocate a new symbol modpost: make multiple export error modpost: dump Module.symvers in the same order of modules.order modpost: traverse the namespace_list in order modpost: use doubly linked list for dump_lists modpost: traverse unresolved symbols in order ...
2022-05-25Merge tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drmLinus Torvalds
Pull drm updates from Dave Airlie: "Intel have enabled DG2 on certain SKUs for laptops, AMD has started some new GPU support, msm has user allocated VA controls dma-buf: - add dma_resv_replace_fences - add dma_resv_get_singleton - make dma_excl_fence private core: - EDID parser refactorings - switch drivers to drm_mode_copy/duplicate - DRM managed mutex initialization display-helper: - put HDMI, SCDC, HDCP, DSC and DP into new module gem: - rework fence handling ttm: - rework bulk move handling - add common debugfs for resource managers - convert to kvcalloc format helpers: - support monochrome formats - RGB888, RGB565 to XRGB8888 conversions fbdev: - cfb/sys_imageblit fixes - pagelist corruption fix - create offb platform device - deferred io improvements sysfb: - Kconfig rework - support for VESA mode selection bridge: - conversions to devm_drm_of_get_bridge - conversions to panel_bridge - analogix_dp - autosuspend support - it66121 - audio support - tc358767 - DSI to DPI support - icn6211 - PLL/I2C fixes, DT property - adv7611 - enable DRM_BRIDGE_OP_HPD - anx7625 - fill ELD if no monitor - dw_hdmi - add audio support - lontium LT9211 support, i.MXMP LDB - it6505: Kconfig fix, DPCD set power fix - adv7511 - CEC support for ADV7535 panel: - ltk035c5444t, B133UAN01, NV3052C panel support - DataImage FG040346DSSWBG04 support - st7735r - DT bindings fix - ssd130x - fixes i915: - DG2 laptop PCI-IDs ("motherboard down") - Initial RPL-P PCI IDs - compute engine ABI - DG2 Tile4 support - DG2 CCS clear color compression support - DG2 render/media compression formats support - ATS-M platform info - RPL-S PCI IDs added - Bump ADL-P DMC version to v2.16 - Support static DRRS - Support multiple eDP/LVDS native mode refresh rates - DP HDR support for HSW+ - Lots of display refactoring + fixes - GuC hwconfig support and query - sysfs support for multi-tile - fdinfo per-client gpu utilisation - add geometry subslices query - fix prime mmap with LMEM - fix vm open count and remove vma refcounts - contiguous allocation fixes - steered register write support - small PCI BAR enablement - GuC error capture support - sunset igpu legacy mmap support for newer devices - GuC version 70.1.1 support amdgpu: - Initial SoC21 support - SMU 13.x enablement - SMU 13.0.4 support - ttm_eu cleanups - USB-C, GPUVM updates - TMZ fixes for RV - RAS support for VCN - PM sysfs code cleanup - DC FP rework - extend CG/PG flags to 64-bit - SI dpm lockdep fix - runtime PM fixes amdkfd: - RAS/SVM fixes - TLB flush fixes - CRIU GWS support - ignore bogus MEC signals more efficiently msm: - Fourcc modifier for tiled but not compressed layouts - Support for userspace allocated IOVA (GPU virtual address) - DPU: DSC (Display Stream Compression) support - DP: eDP support - DP: conversion to use drm_bridge and drm_bridge_connector - Merge DPU1 and MDP5 MDSS driver - DPU: writeback support nouveau: - make some structures static - make some variables static - switch to drm_gem_plane_helper_prepare_fb radeon: - misc fixes/cleanups mxsfb: - rework crtc mode setting - LCDIF CRC support etnaviv: - fencing improvements - fix address space collisions - cleanup MMU reference handling gma500: - GEM/GTT improvements - connector handling fixes komeda: - switch to plane reset helper mediatek: - MIPI DSI improvements omapdrm: - GEM improvements qxl: - aarch64 support vc4: - add a CL submission tracepoint - HDMI YUV support - HDMI/clock improvements - drop is_hdmi caching virtio: - remove restriction of non-zero blob types vmwgfx: - support for cursormob and cursorbypass 4 - fence improvements tidss: - reset DISPC on startup solomon: - SPI support - DT improvements sun4i: - allwinner D1 support - drop is_hdmi caching imx: - use swap() instead of open-coding - use devm_platform_ioremap_resource - remove redunant initializations ast: - Displayport support rockchip: - Refactor IOMMU initialisation - make some structures static - replace drm_detect_hdmi_monitor with drm_display_info.is_hdmi - support swapped YUV formats, - clock improvements - rk3568 support - VOP2 support mediatek: - MT8186 support tegra: - debugabillity improvements" * tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drm: (1740 commits) drm/i915/dsi: fix VBT send packet port selection for ICL+ drm/i915/uc: Fix undefined behavior due to shift overflowing the constant drm/i915/reg: fix undefined behavior due to shift overflowing the constant drm/i915/gt: Fix use of static in macro mismatch drm/i915/audio: fix audio code enable/disable pipe logging drm/i915: Fix CFI violation with show_dynamic_id() drm/i915: Fix 'mixing different enum types' warnings in intel_display_power.c drm/i915/gt: Fix build error without CONFIG_PM drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path drm/msm/dpu: add DRM_MODE_ROTATE_180 back to supported rotations drm/msm: don't free the IRQ if it was not requested drm/msm/dpu: limit writeback modes according to max_linewidth drm/amd: Don't reset dGPUs if the system is going to s2idle drm/amdgpu: Unmap legacy queue when MES is enabled drm: msm: fix possible memory leak in mdp5_crtc_cursor_set() drm/msm: Fix fb plane offset calculation drm/msm/a6xx: Fix refcount leak in a6xx_gpu_init drm/msm/dsi: don't powerup at modeset time for parade-ps8640 drm/rockchip: Change register space names in vop2 dt-bindings: display: rockchip: make reg-names mandatory for VOP2 ...
2022-05-23Merge tag 'x86_build_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build updates from Borislav Petkov: - Add a "make x86_debug.config" target which enables a bunch of useful config debug options when trying to debug an issue - A gcc-12 build warnings fix * tag 'x86_build_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Wrap literal addresses in absolute_pointer() x86/configs: Add x86 debugging Kconfig fragment plus docs
2022-05-23Merge tag 'x86_tdx_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull Intel TDX support from Borislav Petkov: "Intel Trust Domain Extensions (TDX) support. This is the Intel version of a confidential computing solution called Trust Domain Extensions (TDX). This series adds support to run the kernel as part of a TDX guest. It provides similar guest protections to AMD's SEV-SNP like guest memory and register state encryption, memory integrity protection and a lot more. Design-wise, it differs from AMD's solution considerably: it uses a software module which runs in a special CPU mode called (Secure Arbitration Mode) SEAM. As the name suggests, this module serves as sort of an arbiter which the confidential guest calls for services it needs during its lifetime. Just like AMD's SNP set, this series reworks and streamlines certain parts of x86 arch code so that this feature can be properly accomodated" * tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) x86/tdx: Fix RETs in TDX asm x86/tdx: Annotate a noreturn function x86/mm: Fix spacing within memory encryption features message x86/kaslr: Fix build warning in KASLR code in boot stub Documentation/x86: Document TDX kernel architecture ACPICA: Avoid cache flush inside virtual machines x86/tdx/ioapic: Add shared bit for IOAPIC base address x86/mm: Make DMA memory shared for TD guest x86/mm/cpa: Add support for TDX shared memory x86/tdx: Make pages shared in ioremap() x86/topology: Disable CPU online/offline control for TDX guests x86/boot: Avoid #VE during boot for TDX platforms x86/boot: Set CR0.NE early and keep it set during the boot x86/acpi/x86/boot: Add multiprocessor wake-up support x86/boot: Add a trampoline for booting APs via firmware handoff x86/tdx: Wire up KVM hypercalls x86/tdx: Port I/O: Add early boot support x86/tdx: Port I/O: Add runtime hypercalls x86/boot: Port I/O: Add decompression-time support for TDX x86/boot: Port I/O: Allow to hook up alternative helpers ...
2022-05-23Merge tag 'x86_sev_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull AMD SEV-SNP support from Borislav Petkov: "The third AMD confidential computing feature called Secure Nested Paging. Add to confidential guests the necessary memory integrity protection against malicious hypervisor-based attacks like data replay, memory remapping and others, thus achieving a stronger isolation from the hypervisor. At the core of the functionality is a new structure called a reverse map table (RMP) with which the guest has a say in which pages get assigned to it and gets notified when a page which it owns, gets accessed/modified under the covers so that the guest can take an appropriate action. In addition, add support for the whole machinery needed to launch a SNP guest, details of which is properly explained in each patch. And last but not least, the series refactors and improves parts of the previous SEV support so that the new code is accomodated properly and not just bolted on" * tag 'x86_sev_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) x86/entry: Fixup objtool/ibt validation x86/sev: Mark the code returning to user space as syscall gap x86/sev: Annotate stack change in the #VC handler x86/sev: Remove duplicated assignment to variable info x86/sev: Fix address space sparse warning x86/sev: Get the AP jump table address from secrets page x86/sev: Add missing __init annotations to SEV init routines virt: sevguest: Rename the sevguest dir and files to sev-guest virt: sevguest: Change driver name to reflect generic SEV support x86/boot: Put globals that are accessed early into the .data section x86/boot: Add an efi.h header for the decompressor virt: sevguest: Fix bool function returning negative value virt: sevguest: Fix return value check in alloc_shared_pages() x86/sev-es: Replace open-coded hlt-loop with sev_es_terminate() virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement virt: sevguest: Add support to get extended report virt: sevguest: Add support to derive key virt: Add SEV-SNP guest driver x86/sev: Register SEV-SNP guest request platform device x86/sev: Provide support for SNP guest request NAEs ...
2022-05-19x86/boot: Wrap literal addresses in absolute_pointer()Kees Cook
GCC 11 (incorrectly[1]) assumes that literal values cast to (void *) should be treated like a NULL pointer with an offset, and raises diagnostics when doing bounds checking under -Warray-bounds. GCC 12 got "smarter" about finding these: In function 'rdfs8', inlined from 'vga_recalc_vertical' at /srv/code/arch/x86/boot/video-mode.c:124:29, inlined from 'set_mode' at /srv/code/arch/x86/boot/video-mode.c:163:3: /srv/code/arch/x86/boot/boot.h:114:9: warning: array subscript 0 is outside array bounds of 'u8[0]' {aka 'unsigned char[]'} [-Warray-bounds] 114 | asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr)); | ^~~ This has been solved in other places[2] already by using the recently added absolute_pointer() macro. Do the same here. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578 [2] https://lore.kernel.org/all/20210912160149.2227137-1-linux@roeck-us.net/ Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20220227195918.705219-1-keescook@chromium.org
2022-05-11kbuild: factor out the common installation code into scripts/install.shMasahiro Yamada
Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-03efi: x86: Set the NX-compatibility flag in the PE headerPeter Jones
Following Baskov Evgeniy's "Handle UEFI NX-restricted page tables" patches, it's safe to set this compatibility flag to let loaders know they don't need to make special accommodations for kernel to load if pre-boot NX is enabled. Signed-off-by: Peter Jones <pjones@redhat.com> Link: https://lore.kernel.org/all/20220329184743.798513-1-pjones@redhat.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-04-20x86/boot: Put globals that are accessed early into the .data sectionMichael Roth
The helpers in arch/x86/boot/compressed/efi.c might be used during early boot to access the EFI system/config tables, and in some cases these EFI helpers might attempt to print debug/error messages, before console_init() has been called. __putstr() checks some variables to avoid printing anything before the console has been initialized, but this isn't enough since those variables live in .bss, which may not have been cleared yet. This can lead to a triple-fault occurring, primarily when booting in legacy/CSM mode (where EFI helpers will attempt to print some debug messages). Fix this by declaring these globals in .data section instead so there is no dependency on .bss being cleared before accessing them. Fixes: c01fce9cef849 ("x86/compressed: Add SEV-SNP feature detection/setup") Reported-by: Borislav Petkov <bp@suse.de> Suggested-by: Thomas Lendacky <Thomas.Lendacky@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220420152613.145077-1-michael.roth@amd.com
2022-04-17x86/boot: Add an efi.h header for the decompressorBorislav Petkov
Copy the needed symbols only and remove the kernel proper includes. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/YlCKWhMJEMUgJmjF@zn.tnic
2022-04-07x86/boot: Avoid #VE during boot for TDX platformsSean Christopherson
There are a few MSRs and control register bits that the kernel normally needs to modify during boot. But, TDX disallows modification of these registers to help provide consistent security guarantees. Fortunately, TDX ensures that these are all in the correct state before the kernel loads, which means the kernel does not need to modify them. The conditions to avoid are: * Any writes to the EFER MSR * Clearing CR4.MCE This theoretically makes the guest boot more fragile. If, for instance, EFER was set up incorrectly and a WRMSR was performed, it will trigger early exception panic or a triple fault, if it's before early exceptions are set up. However, this is likely to trip up the guest BIOS long before control reaches the kernel. In any case, these kinds of problems are unlikely to occur in production environments, and developers have good debug tools to fix them quickly. Change the common boot code to work on TDX and non-TDX systems. This should have no functional effect on non-TDX systems. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-24-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Set CR0.NE early and keep it set during the bootKirill A. Shutemov
TDX guest requires CR0.NE to be set. Clearing the bit triggers #GP(0). If CR0.NE is 0, the MS-DOS compatibility mode for handling floating-point exceptions is selected. In this mode, the software exception handler for floating-point exceptions is invoked externally using the processor’s FERR#, INTR, and IGNNE# pins. Using FERR# and IGNNE# to handle floating-point exception is deprecated. CR0.NE=0 also limits newer processors to operate with one logical processor active. Kernel uses CR0_STATE constant to initialize CR0. It has NE bit set. But during early boot kernel has more ad-hoc approach to setting bit in the register. During some of this ad-hoc manipulation, CR0.NE is cleared. This causes a #GP in TDX guests and makes it die in early boot. Make CR0 initialization consistent, deriving the initial value of CR0 from CR0_STATE. Since CR0_STATE always has CR0.NE=1, this ensures that CR0.NE is never 0 and avoids the #GP. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-23-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Port I/O: Add decompression-time support for TDXKirill A. Shutemov
Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Hook up TDX-specific port I/O helpers if booting in TDX environment. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-17-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Port I/O: Allow to hook up alternative helpersKirill A. Shutemov
Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Add a way to hook up alternative port I/O helpers in the boot stub with a new pio_ops structure. For now, set the ops structure to just call the normal I/O operation functions. out*()/in*() macros redefined to use pio_ops callbacks. It eliminates need in changing call sites. io_delay() changed to use port I/O helper instead of inline assembly. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-16-kirill.shutemov@linux.intel.com
2022-04-07x86: Consolidate port I/O helpersKirill A. Shutemov
There are two implementations of port I/O helpers: one in the kernel and one in the boot stub. Move the helpers required for both to <asm/shared/io.h> and use the one implementation everywhere. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-15-kirill.shutemov@linux.intel.com
2022-04-07x86/tdx: Detect TDX at early kernel decompression timeKuppuswamy Sathyanarayanan
The early decompression code does port I/O for its console output. But, handling the decompression-time port I/O demands a different approach from normal runtime because the IDT required to support #VE based port I/O emulation is not yet set up. Paravirtualizing I/O calls during the decompression step is acceptable because the decompression code doesn't have a lot of call sites to IO instruction. To support port I/O in decompression code, TDX must be detected before the decompression code might do port I/O. Detect whether the kernel runs in a TDX guest. Add an early_is_tdx_guest() interface to query the cached TDX guest status in the decompression code. TDX is detected with CPUID. Make cpuid_count() accessible outside boot/cpuflags.c. TDX detection in the main kernel is very similar. Move common bits into <asm/shared/tdx.h>. The actual port I/O paravirtualization will come later in the series. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-13-kirill.shutemov@linux.intel.com
2022-04-07x86/sev: Use firmware-validated CPUID for SEV-SNP guestsMichael Roth
SEV-SNP guests will be provided the location of special 'secrets' and 'CPUID' pages via the Confidential Computing blob. This blob is provided to the run-time kernel either through a boot_params field that was initialized by the boot/compressed kernel, or via a setup_data structure as defined by the Linux Boot Protocol. Locate the Confidential Computing blob from these sources and, if found, use the provided CPUID page/table address to create a copy that the run-time kernel will use when servicing CPUID instructions via a #VC handler. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-40-brijesh.singh@amd.com
2022-04-07x86/sev: Add SEV-SNP feature detection/setupMichael Roth
Initial/preliminary detection of SEV-SNP is done via the Confidential Computing blob. Check for it prior to the normal SEV/SME feature initialization, and add some sanity checks to confirm it agrees with SEV-SNP CPUID/MSR bits. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-39-brijesh.singh@amd.com
2022-04-07x86/compressed/64: Add identity mapping for Confidential Computing blobMichael Roth
The run-time kernel will need to access the Confidential Computing blob very early during boot to access the CPUID table it points to. At that stage, it will be relying on the identity-mapped page table set up by the boot/compressed kernel, so make sure the blob and the CPUID table it points to are mapped in advance. [ bp: Massage. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-38-brijesh.singh@amd.com
2022-04-07x86/compressed: Export and rename add_identity_map()Michael Roth
SEV-specific code will need to add some additional mappings, but doing this within ident_map_64.c requires some SEV-specific helpers to be exported and some SEV-specific struct definitions to be pulled into ident_map_64.c. Instead, export add_identity_map() so SEV-specific (and other subsystem-specific) code can be better contained outside of ident_map_64.c. While at it, rename the function to kernel_add_identity_map(), similar to the kernel_ident_mapping_init() function it relies upon. No functional changes. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-37-brijesh.singh@amd.com
2022-04-07x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guestsMichael Roth
SEV-SNP guests will be provided the location of special 'secrets' 'CPUID' pages via the Confidential Computing blob. This blob is provided to the boot kernel either through an EFI config table entry, or via a setup_data structure as defined by the Linux Boot Protocol. Locate the Confidential Computing from these sources and, if found, use the provided CPUID page/table address to create a copy that the boot kernel will use when servicing CPUID instructions via a #VC CPUID handler. [ bp: s/cpuid/CPUID/ ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-36-brijesh.singh@amd.com
2022-04-07x86/compressed: Add SEV-SNP feature detection/setupMichael Roth
Initial/preliminary detection of SEV-SNP is done via the Confidential Computing blob. Check for it prior to the normal SEV/SME feature initialization, and add some sanity checks to confirm it agrees with SEV-SNP CPUID/MSR bits. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-35-brijesh.singh@amd.com
2022-04-07x86/sev: Move MSR-based VMGEXITs for CPUID to helperMichael Roth
This code will also be used later for SEV-SNP-validated CPUID code in some cases, so move it to a common helper. While here, also add a check to terminate in cases where the CPUID function/subfunction is indexed and the subfunction is non-zero, since the GHCB MSR protocol does not support non-zero subfunctions. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-32-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI kexec handling into common codeMichael Roth
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. In this instance, the current acpi.c kexec handling is mainly used to get the alternative EFI config table address provided by kexec via a setup_data entry of type SETUP_EFI. If not present, the code then falls back to normal EFI config table address provided by EFI system table. This would need to be done by all call-sites attempting to access the EFI config table, so just have efi_get_conf_table() handle that automatically. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-29-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI vendor table lookup to helperMichael Roth
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Unbreak unnecessarily broken lines. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-28-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI config table lookup to helperMichael Roth
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Remove superfluous zeroing of a stack variable. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-27-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI system table lookup to helperMichael Roth
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-26-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI detection to helperMichael Roth
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. First, carve out the functionality which determines the EFI environment type the machine is booting on. [ bp: Massage commit message. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-25-brijesh.singh@amd.com
2022-04-06x86/compressed: Register GHCB memory when SEV-SNP is activeBrijesh Singh
The SEV-SNP guest is required by the GHCB spec to register the GHCB's Guest Physical Address (GPA). This is because the hypervisor may prefer that a guest use a consistent and/or specific GPA for the GHCB associated with a vCPU. For more information, see the GHCB specification section "GHCB GPA Registration". If hypervisor can not work with the guest provided GPA then terminate the guest boot. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com> Link: https://lore.kernel.org/r/20220307213356.2797205-17-brijesh.singh@amd.com
2022-04-06x86/compressed: Add helper for validating pages in the decompression stageBrijesh Singh
Many of the integrity guarantees of SEV-SNP are enforced through the Reverse Map Table (RMP). Each RMP entry contains the GPA at which a particular page of DRAM should be mapped. The VMs can request the hypervisor to add pages in the RMP table via the Page State Change VMGEXIT defined in the GHCB specification. Inside each RMP entry is a Validated flag; this flag is automatically cleared to 0 by the CPU hardware when a new RMP entry is created for a guest. Each VM page can be either validated or invalidated, as indicated by the Validated flag in the RMP entry. Memory access to a private page that is not validated generates a #VC. A VM must use the PVALIDATE instruction to validate a private page before using it. To maintain the security guarantee of SEV-SNP guests, when transitioning pages from private to shared, the guest must invalidate the pages before asking the hypervisor to change the page state to shared in the RMP table. After the pages are mapped private in the page table, the guest must issue a page state change VMGEXIT to mark the pages private in the RMP table and validate them. Upon boot, BIOS should have validated the entire system memory. During the kernel decompression stage, early_setup_ghcb() uses set_page_decrypted() to make the GHCB page shared (i.e. clear encryption attribute). And while exiting from the decompression, it calls set_page_encrypted() to make the page private. Add snp_set_page_{private,shared}() helpers that are used by set_page_{decrypted,encrypted}() to change the page state in the RMP table. [ bp: Massage commit message and comments. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-16-brijesh.singh@amd.com