kernel/linux.git/include/xen/interface/features.h, branch v6.19.11

xen: fix wrong SPDX headers of Xen related headers

2021-11-02T12:45:44+00:00

Commit b24413180f5600 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") was meant to do a tree-wide cleanup for files without any license information by adding a SPDX GPL-2.0 line to them. Unfortunately this was applied even to several Xen-related headers which have been originally under the MIT license, but obviously have been copied to the Linux tree from the Xen project without keeping the license boiler plate as required. Correct that by changing the license of those files back to "MIT". Some files still contain the MIT license text. Replace that by the related SPDX line. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20211015143312.29900-1-jgross@suse.com Signed-off-by: Boris Ostrovsky

xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped

2021-04-23T09:33:50+00:00

Newer Xen versions expose two Xen feature flags to tell us if the domain is directly mapped or not. Only when a domain is directly mapped it makes sense to enable swiotlb-xen on ARM. Introduce a function on ARM to check the new Xen feature flags and also to deal with the legacy case. Call the function xen_swiotlb_detect. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org Signed-off-by: Juergen Gross

xen/pvh: Indicate XENFEAT_linux_rsdp_unrestricted to Xen

2018-04-10T13:22:22+00:00

Pre-4.17 kernels ignored start_info's rsdp_paddr pointer and instead relied on finding RSDP in standard location in BIOS RO memory. This has worked since that's where Xen used to place it. However, with recent Xen change (commit 4a5733771e6f ("libxl: put RSDP for PVH guest near 4GB")) it prefers to keep RSDP at a "non-standard" address. Even though as of commit b17d9d1df3c3 ("x86/xen: Add pvh specific rsdp address retrieval function") Linux is able to find RSDP, for back-compatibility reasons we need to indicate to Xen that we can handle this, an we do so by setting XENFEAT_linux_rsdp_unrestricted flag in ELF notes. (Also take this opportunity and sync features.h header file with Xen) Signed-off-by: Boris Ostrovsky Reviewed-by: Juergen Gross Reviewed-by: Wei Liu

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

xen/gntdev: mark userspace PTEs as special on x86 PV guests

2015-01-28T14:04:21+00:00

In an x86 PV guest, get_user_pages_fast() on a userspace address range containing foreign mappings does not work correctly because the M2P lookup of the MFN from a userspace PTE may return the wrong page. Force get_user_pages_fast() to fail on such addresses by marking the PTEs as special. If Xen has XENFEAT_gnttab_map_avail_bits (available since at least 4.0), we can do so efficiently in the grant map hypercall. Otherwise, it needs to be done afterwards. This is both inefficient and racy (the mapping is visible to the task before we fixup the PTEs), but will be fine for well-behaved applications that do not use the mapping until after the mmap() system call returns. Guests with XENFEAT_auto_translated_physmap (ARM and x86 HVM or PVH) do not need this since get_user_pages() has always worked correctly for them. Signed-off-by: David Vrabel Reviewed-by: Stefano Stabellini

xen/arm: remove handling of XENFEAT_grant_map_identity

2014-12-04T12:41:45+00:00

The feature has been removed from Xen. Also Linux cannot use it on ARM32 without CONFIG_ARM_LPAE. Signed-off-by: Stefano Stabellini Acked-by: Ian Campbell Reviewed-by: David Vrabel Reviewed-by: Catalin Marinas

xen/arm: introduce XENFEAT_grant_map_identity

2014-09-11T18:11:52+00:00

The flag tells us that the hypervisor maps a grant page to guest physical address == machine address of the page in addition to the normal grant mapping address. It is needed to properly issue cache maintenance operation at the completion of a DMA operation involving a foreign grant. Signed-off-by: Stefano Stabellini Tested-by: Denis Schneider

xen/arm: get privilege status

2012-08-08T17:20:18+00:00

Use Xen features to figure out if we are privileged. XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg. Signed-off-by: Stefano Stabellini Acked-by: Konrad Rzeszutek Wilk

xen: support GSI -> pirq remapping in PV on HVM guests

2010-10-22T20:25:42+00:00

Disable pcifront when running on HVM: it is meant to be used with pv guests that don't have PCI bus. Use acpi_register_gsi_xen_hvm to remap GSIs into pirqs. Signed-off-by: Stefano Stabellini Reviewed-by: Konrad Rzeszutek Wilk

x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.

2010-07-27T06:13:25+00:00

Use xen_vcpuop_clockevent instead of hpet and APIC timers as main clockevent device on all vcpus, use the xen wallclock time as wallclock instead of rtc and use xen_clocksource as clocksource. The pv clock algorithm needs to work correctly for the xen_clocksource and xen wallclock to be usable, only modern Xen versions offer a reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock). Using the hpet as clocksource means a VMEXIT every time we read/write to the hpet mmio addresses, pvclock give us a better rating without VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent Signed-off-by: Stefano Stabellini Signed-off-by: Don Dutile Signed-off-by: Jeremy Fitzhardinge