kernel.git/arch/x86/kernel/smpboot.c, branch linux-5.19.y

Merge tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T01:17:09Z

Pull x86 cleanups from Borislav Petkov: - Serious sanitization and cleanup of the whole APERF/MPERF and frequency invariance code along with removing the need for unnecessary IPIs - Finally remove a.out support - The usual trivial cleanups and fixes all over x86 * tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86: Remove empty files x86/speculation: Add missing srbds=off to the mitigations= help text x86/prctl: Remove pointless task argument x86/aperfperf: Make it correct on 32bit and UP kernels x86/aperfmperf: Integrate the fallback code from show_cpuinfo() x86/aperfmperf: Replace arch_freq_get_on_cpu() x86/aperfmperf: Replace aperfmperf_get_khz() x86/aperfmperf: Store aperf/mperf data for cpu frequency reads x86/aperfmperf: Make parts of the frequency invariance code unconditional x86/aperfmperf: Restructure arch_scale_freq_tick() x86/aperfmperf: Put frequency invariance aperf/mperf data into a struct x86/aperfmperf: Untangle Intel and AMD frequency invariance init x86/aperfmperf: Separate AP/BP frequency invariance init x86/smp: Move APERF/MPERF code where it belongs x86/aperfmperf: Dont wake idle CPUs in arch_freq_get_on_cpu() x86/process: Fix kernel-doc warning due to a changed function name x86: Remove a.out support x86/mm: Replace nodes_weight() with nodes_empty() where appropriate x86: Replace cpumask_weight() with cpumask_empty() where appropriate x86/pkeys: Remove __arch_set_user_pkey_access() declaration ...

Merge tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-05-24T00:51:12Z

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 ...

x86/aperfmperf: Make parts of the frequency invariance code unconditional

2022-04-27T18:22:19Z

The frequency invariance support is currently limited to x86/64 and SMP, which is the vast majority of machines. arch_scale_freq_tick() is called every tick on all CPUs and reads the APERF and MPERF MSRs. The CPU frequency getters function do the same via dedicated IPIs. While it could be argued that on systems where frequency invariance support is disabled (32bit, !SMP) the per tick read of the APERF and MPERF MSRs can be avoided, it does not make sense to keep the extra code and the resulting runtime issues of mass IPIs around. As a first step split out the non frequency invariance specific initialization code and the read MSR portion of arch_scale_freq_tick(). The rest of the code is still conditional and guarded with a static key. Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220415161206.761988704@linutronix.de

x86/aperfmperf: Untangle Intel and AMD frequency invariance init

2022-04-27T18:22:19Z

AMD boot CPU initialization happens late via ACPI/CPPC which prevents the Intel parts from being marked __init. Split out the common code and provide a dedicated interface for the AMD initialization and mark the Intel specific code and data __init. The remaining text size is almost cut in half: text: 2614 -> 1350 init.text: 0 -> 786 Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220415161206.592465719@linutronix.de

x86/aperfmperf: Separate AP/BP frequency invariance init

2022-04-27T13:51:08Z

This code is convoluted and because it can be invoked post init via the ACPI/CPPC code, all of the initialization functionality is built in instead of being part of init text and init data. As a first step create separate calls for the boot and the application processors. Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220415161206.536733494@linutronix.de

x86/smp: Move APERF/MPERF code where it belongs

2022-04-27T13:51:08Z

as this can share code with the preexisting APERF/MPERF code. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220415161206.478362457@linutronix.de

x86/boot: Add a trampoline for booting APs via firmware handoff

2022-04-07T15:27:52Z

Historically, x86 platforms have booted secondary processors (APs) using INIT followed by the start up IPI (SIPI) messages. In regular VMs, this boot sequence is supported by the VMM emulation. But such a wakeup model is fatal for secure VMs like TDX in which VMM is an untrusted entity. To address this issue, a new wakeup model was added in ACPI v6.4, in which firmware (like TDX virtual BIOS) will help boot the APs. More details about this wakeup model can be found in ACPI specification v6.4, the section titled "Multiprocessor Wakeup Structure". Since the existing trampoline code requires processors to boot in real mode with 16-bit addressing, it will not work for this wakeup model (because it boots the AP in 64-bit mode). To handle it, extend the trampoline code to support 64-bit mode firmware handoff. Also, extend IDT and GDT pointers to support 64-bit mode hand off. There is no TDX-specific detection for this new boot method. The kernel will rely on it as the sole boot method whenever the new ACPI structure is present. The ACPI table parser for the MADT multiprocessor wake up structure and the wakeup method that uses this structure will be added by the following patch in this series. Signed-off-by: Sean Christopherson Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kirill A. Shutemov Signed-off-by: Dave Hansen Reviewed-by: Andi Kleen Reviewed-by: Dan Williams Reviewed-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20220405232939.73860-21-kirill.shutemov@linux.intel.com

x86/sev: Use SEV-SNP AP creation to start secondary CPUs

2022-04-06T15:06:49Z

To provide a more secure way to start APs under SEV-SNP, use the SEV-SNP AP Creation NAE event. This allows for guest control over the AP register state rather than trusting the hypervisor with the SEV-ES Jump Table address. During native_smp_prepare_cpus(), invoke an SEV-SNP function that, if SEV-SNP is active, will set/override apic->wakeup_secondary_cpu. This will allow the SEV-SNP AP Creation NAE event method to be used to boot the APs. As a result of installing the override when SEV-SNP is active, this method of starting the APs becomes the required method. The override function will fail to start the AP if the hypervisor does not have support for AP creation. [ bp: Work in forgotten review comments. ] Signed-off-by: Tom Lendacky Signed-off-by: Brijesh Singh Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20220307213356.2797205-23-brijesh.singh@amd.com

x86/ACPI: CPPC: Move init_freq_invariance_cppc() into x86 CPPC

2022-03-08T18:16:43Z

The init_freq_invariance_cppc code actually doesn't need the SMP functionality. So setting the CONFIG_SMP as the check condition for init_freq_invariance_cppc may cause the confusion to misunderstand the CPPC. And the x86 CPPC file is better space to store the CPPC related functions, while the init_freq_invariance_cppc is out of smpboot, that means, the CONFIG_SMP won't be mandatory condition any more. And It's more clear than before. Signed-off-by: Huang Rui [ rjw: Subject adjustment ] Signed-off-by: Rafael J. Wysocki

x86: Expose init_freq_invariance() to topology header

2022-03-08T18:16:43Z

The function init_freq_invariance will be used on x86 CPPC, so expose it in the topology header. Signed-off-by: Huang Rui [ rjw: Subject adjustment ] Signed-off-by: Rafael J. Wysocki