Re: Assertion '!is_idle_vcpu(v)' failed after 'Remove fully_eager_fpu' commit on EFI

["Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>]

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On Fri, Jun 12, 2026 at 03:53:49PM +0200, Anthony PERARD wrote:
> Hi,
> 
> Since commit dba44e051209 ("x86: Remove fully_eager_fpu"), I can't boot
> a machine and get assertion '!is_idle_vcpu(v)' failed instead. It's
> netbooted and EFI.
> 
> Xen call trace:
>    [<ffff82d04033da2c>] R vcpu_save_fpu+0x65/0xdc
>    [<ffff82d04029c5c4>] S efi_rs_enter+0x37/0x16a
>    [<ffff82d04029c7e3>] F efi_get_time+0x19/0xb2
>    [<ffff82d04047cbf0>] F init_xen_time+0x1e3/0x2b4
>    [<ffff82d040477a49>] F __start_xen+0x1d71/0x24b8
>    [<ffff82d0402043e7>] F __high_start+0xb7/0xc0
> 
> Assertion '!is_idle_vcpu(v)' failed at arch/x86/i387.c:195
> 
> A few more lines from Xen:
>     CPU Vendor: Intel, Family 6 (0x6), Model 86 (0x56), Stepping 3 (raw 00050663)
>     Bootloader: GRUB 2.06
>     [...]
>     Enabling APIC mode.  Using 2 I/O APICs
>     ENABLING IO-APIC IRQs
>      -> Using old ACK method
>      ..TIMER: vector=0xF0 apic1=0 pin1=2 apic2=-1 pin2=-1
>     TSC deadline timer enabled
>     Assertion '!is_idle_vcpu(v)' failed at arch/x86/i387.c:195
> 
> Commit this Xen is built from: 50936ea05660.

Interesting, the efi_get_time() way is nowadays a fallback if cmos one
isn't advertised. Can you try adding `cmos-rtc-probe`?

Anyway, surely it shouldn't crash... The commit you mentioned has "No
functional change intended", but well...

> full logs at:
>     https://paste.vates.tech/?bd8a9a0955798a97#A1DU2efwUt7bbHQUxdo9UXGcsJ2XPNJNZHPz87LqLtcF

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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