kernel/linux.git/Documentation/x86, branch v6.1.168

x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT

2024-04-03T13:19:47+00:00

commit 29956748339aa8757a7e2f927a8679dd08f24bb6 upstream. It was meant well at the time but nothing's using it so get rid of it. Signed-off-by: Borislav Petkov (AMD) Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20240202163510.GDZb0Zvj8qOndvFOiZ@fat_crate.local Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key

2024-03-06T14:45:20+00:00

commit 6613d82e617dd7eb8b0c40b2fe3acea655b1d611 upstream. The VERW mitigation at exit-to-user is enabled via a static branch mds_user_clear. This static branch is never toggled after boot, and can be safely replaced with an ALTERNATIVE() which is convenient to use in asm. Switch to ALTERNATIVE() to use the VERW mitigation late in exit-to-user path. Also remove the now redundant VERW in exc_nmi() and arch_exit_to_user_mode(). Signed-off-by: Pawan Gupta Signed-off-by: Dave Hansen Link: https://lore.kernel.org/all/20240213-delay-verw-v8-4-a6216d83edb7%40linux.intel.com Signed-off-by: Greg Kroah-Hartman

x86/efistub: Simplify and clean up handover entry code

2024-03-06T14:45:18+00:00

From: Ard Biesheuvel [ Commit df9215f15206c2a81909ccf60f21d170801dce38 upstream ] Now that the EFI entry code in assembler is only used by the optional and deprecated EFI handover protocol, and given that the EFI stub C code no longer returns to it, most of it can simply be dropped. While at it, clarify the symbol naming, by merging efi_main() and efi_stub_entry(), making the latter the shared entry point for all different boot modes that enter via the EFI stub. The efi32_stub_entry() and efi64_stub_entry() names are referenced explicitly by the tooling that populates the setup header, so these must be retained, but can be emitted as aliases of efi_stub_entry() where appropriate. Signed-off-by: Ard Biesheuvel Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230807162720.545787-5-ardb@kernel.org Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

x86/sev: Add SEV-SNP guest feature negotiation support

2023-02-01T07:34:50+00:00

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 Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Tom Lendacky Cc: Link: https://lore.kernel.org/r/20230118061943.534309-1-nikunj@amd.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'x86_microcode_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-10-04T17:12:08+00:00

Pull x75 microcode loader updates from Borislav Petkov: - Get rid of a single ksize() usage - By popular demand, print the previous microcode revision an update was done over - Remove more code related to the now gone MICROCODE_OLD_INTERFACE - Document the problems stemming from microcode late loading * tag 'x86_microcode_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/AMD: Track patch allocation size explicitly x86/microcode: Print previous version of microcode after reload x86/microcode: Remove ->request_microcode_user() x86/microcode: Document the whole late loading problem

docs: x86: replace do_IRQ int the entry_64.rst with common_interrupt()

2022-09-27T19:21:44+00:00

do_IRQ has been replaced by common_interrupt in commit fa5e5c409213 ("x86/entry: Use idtentry for interrupts"). Signed-off-by: Tuo Cao <91tuocao@gmail.com> Link: https://lore.kernel.org/r/20220915150155.9908-1-91tuocao@gmail.com Signed-off-by: Jonathan Corbet

x86/microcode: Document the whole late loading problem

2022-08-18T13:57:53+00:00

Commit d23d33ea0fcd ("x86/microcode: Taint and warn on late loading") started tainting the kernel after microcode late loading. There is some history behind why x86 microcode started doing the late loading stop_machine() rendezvous. Document the whole situation. No functional changes. [ bp: Fix typos, heavily massage. ] Signed-off-by: Ashok Raj Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20220813223825.3164861-2-ashok.raj@intel.com

Merge tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma-mapping

2022-08-06T17:56:45+00:00

Pull dma-mapping updates from Christoph Hellwig: - convert arm32 to the common dma-direct code (Arnd Bergmann, Robin Murphy, Christoph Hellwig) - restructure the PCIe peer to peer mapping support (Logan Gunthorpe) - allow the IOMMU code to communicate an optional DMA mapping length and use that in scsi and libata (John Garry) - split the global swiotlb lock (Tianyu Lan) - various fixes and cleanup (Chao Gao, Dan Carpenter, Dongli Zhang, Lukas Bulwahn, Robin Murphy) * tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma-mapping: (45 commits) swiotlb: fix passing local variable to debugfs_create_ulong() dma-mapping: reformat comment to suppress htmldoc warning PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() RDMA/rw: drop pci_p2pdma_[un]map_sg() RDMA/core: introduce ib_dma_pci_p2p_dma_supported() nvme-pci: convert to using dma_map_sgtable() nvme-pci: check DMA ops when indicating support for PCI P2PDMA iommu/dma: support PCI P2PDMA pages in dma-iommu map_sg iommu: Explicitly skip bus address marked segments in __iommu_map_sg() dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support dma-direct: support PCI P2PDMA pages in dma-direct map_sg dma-mapping: allow EREMOTEIO return code for P2PDMA transfers PCI/P2PDMA: Introduce helpers for dma_map_sg implementations PCI/P2PDMA: Attempt to set map_type if it has not been set lib/scatterlist: add flag for indicating P2PDMA segments in an SGL swiotlb: clean up some coding style and minor issues dma-mapping: update comment after dmabounce removal scsi: sd: Add a comment about limiting max_sectors to shost optimal limit ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors scsi: scsi_transport_sas: cap shost opt_sectors according to DMA optimal limit ...

Merge tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-08-05T17:47:40+00:00

Pull x86 SGX updates from Dave Hansen: "A set of x86/sgx changes focused on implementing the "SGX2" features, plus a minor cleanup: - SGX2 ISA support which makes enclave memory management much more dynamic. For instance, enclaves can now change enclave page permissions on the fly. - Removal of an unused structure member" * tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/sgx: Drop 'page_index' from sgx_backing selftests/sgx: Page removal stress test selftests/sgx: Test reclaiming of untouched page selftests/sgx: Test invalid access to removed enclave page selftests/sgx: Test faulty enclave behavior selftests/sgx: Test complete changing of page type flow selftests/sgx: Introduce TCS initialization enclave operation selftests/sgx: Introduce dynamic entry point selftests/sgx: Test two different SGX2 EAUG flows selftests/sgx: Add test for TCS page permission changes selftests/sgx: Add test for EPCM permission changes Documentation/x86: Introduce enclave runtime management section x86/sgx: Free up EPC pages directly to support large page ranges x86/sgx: Support complete page removal x86/sgx: Support modifying SGX page type x86/sgx: Tighten accessible memory range after enclave initialization x86/sgx: Support adding of pages to an initialized enclave x86/sgx: Support restricting of enclave page permissions x86/sgx: Support VA page allocation without reclaiming x86/sgx: Export sgx_encl_page_alloc() ...

Merge tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

2022-08-03T21:41:36+00:00

Pull efivars sysfs interface removal from Ard Biesheuvel: "Remove the obsolete 'efivars' sysfs based interface to the EFI variable store, now that all users have moved to the efivarfs pseudo file system, which was created ~10 years ago to address some fundamental shortcomings in the sysfs based driver. Move the 'business logic' related to which EFI variables are important and may affect the boot flow from the efivars support layer into the efivarfs pseudo file system, so it is no longer exposed to other parts of the kernel" * tag 'efi-efivars-removal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: vars: Move efivar caching layer into efivarfs efi: vars: Switch to new wrapper layer efi: vars: Remove deprecated 'efivars' sysfs interface