diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2023-05-13 00:07:56 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-05-15 14:45:05 +0300 |
| commit | 0c7ffa32dbd6b09a87fea4ad1de8b27145dfd9a6 (patch) | |
| tree | 640bec0ff4daf801ae9313778d27b1cab268168a /arch/x86/Kconfig | |
| parent | 7e75178a0950c5ceffa2ca3225701b69752f7d3a (diff) | |
| download | linux-0c7ffa32dbd6b09a87fea4ad1de8b27145dfd9a6.tar.xz | |
x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it
Implement the validation function which tells the core code whether
parallel bringup is possible.
The only condition for now is that the kernel does not run in an encrypted
guest as these will trap the RDMSR via #VC, which cannot be handled at that
point in early startup.
There was an earlier variant for AMD-SEV which used the GHBC protocol for
retrieving the APIC ID via CPUID, but there is no guarantee that the
initial APIC ID in CPUID is the same as the real APIC ID. There is no
enforcement from the secure firmware and the hypervisor can assign APIC IDs
as it sees fit as long as the ACPI/MADT table is consistent with that
assignment.
Unfortunately there is no RDMSR GHCB protocol at the moment, so enabling
AMD-SEV guests for parallel startup needs some more thought.
Intel-TDX provides a secure RDMSR hypercall, but supporting that is outside
the scope of this change.
Fixup announce_cpu() as e.g. on Hyper-V CPU1 is the secondary sibling of
CPU0, which makes the @cpu == 1 logic in announce_cpu() fall apart.
[ mikelley: Reported the announce_cpu() fallout
Originally-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205257.467571745@linutronix.de
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c140a73b4295..953823fdf57b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -274,8 +274,9 @@ config X86 select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO + select HOTPLUG_PARALLEL if SMP && X86_64 select HOTPLUG_SMT if SMP - select HOTPLUG_SPLIT_STARTUP if SMP + select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 select IRQ_FORCED_THREADING select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK |