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

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Fri, Jun 12, 2026 at 04:11:28PM +0200, Marek Marczykowski-Górecki wrote:
> 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`?

Yep, that works. I could boot the machine. There's not much changes in
the logs, beside different memory mapping, and otherwise this:

    TSC deadline timer enabled
    Wallclock source: CMOS RTC
    Allocated console ring of 128 KiB.
    mwait-idle: MWAIT substates: 0x2120
    mwait-idle: lapic_timer_reliable_states 0x2
    HPET: 8 timers usable for broadcast (8 total)
    [... the rest of the boot]

Thanks,


--
Anthony Perard | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

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