kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity
No description
1,250,359 commits 117 branches 5,827 tags 6.3 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Kai Huang 5bdd181821 x86/asm: Remove the __iomem annotation of movdir64b()'s dst argument 
Commit e56d28df2f ("x86/virt/tdx: Configure global KeyID on all
packages") causes a sparse warning:

  arch/x86/virt/vmx/tdx/tdx.c:683:27: warning: incorrect type in argument 1 (different address spaces)
  arch/x86/virt/vmx/tdx/tdx.c:683:27:    expected void [noderef] __iomem *dst
  arch/x86/virt/vmx/tdx/tdx.c:683:27:    got void *

The reason is TDX must use the MOVDIR64B instruction to convert TDX
private memory (which is normal RAM but not MMIO) back to normal.  The
TDX code uses existing movdir64b() helper to do that, but the first
argument @dst of movdir64b() is annotated with __iomem.

When movdir64b() was firstly introduced in commit 0888e1030d
("x86/asm: Carve out a generic movdir64b() helper for general usage"),
it didn't have the __iomem annotation.  But this commit also introduced
the same "incorrect type" sparse warning because the iosubmit_cmds512(),
which was the solo caller of movdir64b(), has the __iomem annotation.

This was later fixed by commit 6ae58d8713 ("x86/asm: Annotate
movdir64b()'s dst argument with __iomem").  That fix was reasonable
because until TDX code the movdir64b() was only used to move data to
MMIO location, as described by the commit message:

  ... The current usages send a 64-bytes command descriptor to an MMIO
  location (portal) on a device for consumption. When future usages for
  the MOVDIR64B instruction warrant a separate variant of a memory to
  memory operation, the argument annotation can be revisited.

Now TDX code uses MOVDIR64B to move data to normal memory so it's time
to revisit.

The SDM says the destination of MOVDIR64B is "memory location specified
in a general register", thus it's more reasonable that movdir64b() does
not have the __iomem annotation on the @dst.

Remove the __iomem annotation from the @dst argument of movdir64b() to
fix the sparse warning in TDX code.  Similar to memset_io(), introduce a
new movdir64b_io() to cover the case where the destination is an MMIO
location, and change the solo caller iosubmit_cmds512() to use the new
movdir64b_io().

In movdir64b_io() explicitly use __force in the type casting otherwise
there will be below sparse warning:

  warning: cast removes address space '__iomem' of expression

[ dhansen: normal changelog tweaks ]

Closes: https://lore.kernel.org/oe-kbuild-all/202312311924.tGjsBIQD-lkp@intel.com/
Fixes: e56d28df2f ("x86/virt/tdx: Configure global KeyID on all packages")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Link: https://lore.kernel.org/all/20240126023852.11065-1-kai.huang%40intel.com
History 2024-02-22 14:52:09 -08:00
arch x86/asm: Remove the __iomem annotation of movdir64b()'s dst argument 2024-02-22 14:52:09 -08:00
block blk-iocost: Fix an UBSAN shift-out-of-bounds warning 2024-02-08 10:11:39 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: algif_hash - Remove bogus SGL free on zero-length error path 2024-02-02 18:08:12 +08:00
Documentation Kbuild fixes for v6.8 (2nd) 2024-02-18 10:09:25 -08:00
drivers - Fix GICv4.1 affinity update 2024-02-18 09:14:12 -08:00
fs bcachefs fixes for v6.8-rc5 2024-02-17 13:17:32 -08:00
include Char/Misc changes for 6.8-rc5 2024-02-17 08:52:38 -08:00
init update workarounds for gcc "asm goto" issue 2024-02-15 11:14:33 -08:00
io_uring io_uring/net: fix multishot accept overflow handling 2024-02-14 18:30:19 -07:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel Probes fixes for v6.8-rc4: 2024-02-17 07:59:47 -08:00
lib Driver core fixes for 6.8-rc5 2024-02-17 08:56:41 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/memory: Use exception ip to search exception tables 2024-02-12 23:04:42 +01:00
net Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
rust Rust changes for v6.8 2024-01-11 13:05:41 -08:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
scripts kallsyms: ignore ARMv4 thunks along with others 2024-02-15 22:44:56 +09:00
security lsm/stable-6.8 PR 20240215 2024-02-16 07:58:43 -08:00
sound ALSA: usb-audio: More relaxed check of MIDI jack names 2024-02-15 16:56:05 +01:00
tools powerpc fixes for 6.8 #3 2024-02-17 16:59:31 -08:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt Generic: 2024-01-17 13:03:37 -08:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap Including fixes from can, wireless and netfilter. 2024-02-15 11:39:27 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Driver core fixes for 6.8-rc5 2024-02-17 08:56:41 -08:00
Makefile Linux 6.8-rc5 2024-02-18 12:56:25 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.