linux-dev/arch/x86/kernel/apic, branch master

x86/apic: Don't disable x2APIC if locked

2022-08-31T21:34:11Z

The APIC supports two modes, legacy APIC (or xAPIC), and Extended APIC (or x2APIC). X2APIC mode is mostly compatible with legacy APIC, but it disables the memory-mapped APIC interface in favor of one that uses MSRs. The APIC mode is controlled by the EXT bit in the APIC MSR. The MMIO/xAPIC interface has some problems, most notably the APIC LEAK [1]. This bug allows an attacker to use the APIC MMIO interface to extract data from the SGX enclave. Introduce support for a new feature that will allow the BIOS to lock the APIC in x2APIC mode. If the APIC is locked in x2APIC mode and the kernel tries to disable the APIC or revert to legacy APIC mode a GP fault will occur. Introduce support for a new MSR (IA32_XAPIC_DISABLE_STATUS) and handle the new locked mode when the LEGACY_XAPIC_DISABLED bit is set by preventing the kernel from trying to disable the x2APIC. On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS. If legacy APIC is required, then it SGX and TDX need to be disabled in the BIOS. [1]: https://aepicleak.com/aepicleak.pdf Signed-off-by: Daniel Sneddon Signed-off-by: Dave Hansen Acked-by: Dave Hansen Tested-by: Neelima Krishnan Link: https://lkml.kernel.org/r/20220816231943.1152579-1-daniel.sneddon@linux.intel.com

Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-08-07T17:03:24Z

Pull misc updates from Andrew Morton: "Updates to various subsystems which I help look after. lib, ocfs2, fatfs, autofs, squashfs, procfs, etc. A relatively small amount of material this time" * tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) scripts/gdb: ensure the absolute path is generated on initial source MAINTAINERS: kunit: add David Gow as a maintainer of KUnit mailmap: add linux.dev alias for Brendan Higgins mailmap: update Kirill's email profile: setup_profiling_timer() is moslty not implemented ocfs2: fix a typo in a comment ocfs2: use the bitmap API to simplify code ocfs2: remove some useless functions lib/mpi: fix typo 'the the' in comment proc: add some (hopefully) insightful comments bdi: remove enum wb_congested_state kernel/hung_task: fix address space of proc_dohung_task_timeout_secs lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t() squashfs: support reading fragments in readahead call squashfs: implement readahead squashfs: always build "file direct" version of page actor Revert "squashfs: provide backing_dev_info in order to disable read-ahead" fs/ocfs2: Fix spelling typo in comment ia64: old_rr4 added under CONFIG_HUGETLB_PAGE proc: fix test for "vsyscall=xonly" boot option ...

profile: setup_profiling_timer() is moslty not implemented

2022-07-30T01:12:36Z

The setup_profiling_timer() is mostly un-implemented by many architectures. In many places it isn't guarded by CONFIG_PROFILE which is needed for it to be used. Make it a weak symbol in kernel/profile.c and remove the 'return -EINVAL' implementations from the kenrel. There are a couple of architectures which do return 0 from the setup_profiling_timer() function but they don't seem to do anything else with it. To keep the /proc compatibility for now, leave these for a future update or removal. On ARM, this fixes the following sparse warning: arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org Signed-off-by: Ben Dooks Signed-off-by: Andrew Morton

KVM: x86: lapic: Rename [GET/SET]_APIC_DEST_FIELD to [GET/SET]_XAPIC_DEST_FIELD

2022-06-24T16:44:34Z

To signify that the macros only support 8-bit xAPIC destination ID. Suggested-by: Maxim Levitsky Reviewed-by: Maxim Levitsky Reviewed-by: Pankaj Gupta Signed-off-by: Suravee Suthikulpanit Reviewed-by: Paolo Bonzini Message-Id: <20220519102709.24125-3-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini

Merge tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T02:32:59Z

Pull misc x86 updates from Borislav Petkov: "A variety of fixes which don't fit any other tip bucket: - Remove unnecessary function export - Correct asm constraint - Fix __setup handlers retval" * tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Cleanup the control_va_addr_alignment() __setup handler x86: Fix return value of __setup handlers x86/delay: Fix the wrong asm constraint in delay_loop() x86/amd_nb: Unexport amd_cache_northbridges()

Merge tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T02:16:09Z

Pull x86 APIC updates from Borislav Petkov: - Always do default APIC routing setup so that cpumasks are properly allocated and are present when later accessed ("nosmp" and x2APIC) - Clarify the bit overlap between an old APIC and a modern, integrated one * tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Do apic driver probe for "nosmp" use case x86/apic: Clarify i82489DX bit overlap in APIC_LVT0

Merge tag 'x86_platform_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T02:11:08Z

Pull x86 platform updates from Borislav Petkov: - A couple of changes enabling SGI UV5 support * tag 'x86_platform_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Log gap hole end size x86/platform/uv: Update TSC sync state for UV5 x86/platform/uv: Update NMI Handler for UV5

x86: Fix return value of __setup handlers

2022-05-04T14:47:57Z

__setup() handlers should return 1 to obsolete_checksetup() in init/main.c to indicate that the boot option has been handled. A return of 0 causes the boot option/value to be listed as an Unknown kernel parameter and added to init's (limited) argument (no '=') or environment (with '=') strings. So return 1 from these x86 __setup handlers. Examples: Unknown kernel command line parameters "apicpmtimer BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init apicpmtimer with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Fixes: 77b52b4c5c66 ("x86: add "debugpat" boot option") Fixes: e16fd002afe2 ("x86/cpufeature: Enable RING3MWAIT for Knights Landing") Fixes: b8ce33590687 ("x86_64: convert to clock events") Reported-by: Igor Zhbanov Signed-off-by: Randy Dunlap Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@infradead.org

x86/apic: Do apic driver probe for "nosmp" use case

2022-05-01T20:40:29Z

For the "nosmp" use case, the APIC initialization code selects "APIC_SYMMETRIC_IO_NO_ROUTING" as the default interrupt mode and avoids probing APIC drivers. This works well for the default APIC modes, but for the x2APIC case the probe function is required to allocate the cluster_hotplug mask. So in the APIC_SYMMETRIC_IO_NO_ROUTING case when the x2APIC is initialized it dereferences a NULL pointer and the kernel crashes. This was observed on a TDX platform where x2APIC is enabled and "nosmp" command line option is allowed. To fix this issue, probe APIC drivers via default_setup_apic_routing() for the APIC_SYMMETRIC_IO_NO_ROUTING interrupt mode too. Suggested-by: Kirill A. Shutemov Suggested-by: Rafael J. Wysocki Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Link: https://lore.kernel.org/r/a64f864e1114bcd63593286aaf61142cfce384ea.1650076869.git.sathyanarayanan.kuppuswamy@intel.com

x86/apic: Clarify i82489DX bit overlap in APIC_LVT0

2022-04-13T16:39:48Z

Daniel stumbled over the bit overlap of the i82498DX external APIC and the TSC deadline timer configuration bit in modern APICs, which is neither documented in the code nor in the current SDM. Maciej provided links to the original i82489DX/486 documentation. See Link. Remove the i82489DX macro maze, use a i82489DX specific define in the apic code and document the overlap in a comment. Reported-by: Daniel Vacek Signed-off-by: Thomas Gleixner Cc: Maciej W. Rozycki Link: https://lore.kernel.org/r/87ee22f3ci.ffs@tglx