Messages in this thread | | | Date | Mon, 14 Nov 2022 10:32:48 +0100 | Subject | Re: [PATCH] x86/xen: call xen_set_upcall_vector() only after local apic setup | From | Jan Beulich <> |
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On 12.11.2022 14:23, Juergen Gross wrote: > Calling xen_set_upcall_vector() before the local APIC has been > initialized results in warnings when setting up the local APIC: > > [ 0.037322] APIC: Stale IRR: 00080000, ... > > Avoid this problem by moving the call of xen_set_upcall_vector() for > APs from xen_cpu_up_prepare_hvm() to a new hotplug callback called on > the AP before interrupts are enabled and after the local APIC has been > initialized. There is already a Xen specific hotplug state defined at > a matching position, but right now it is specific to Arm. So rename > the CPUHP_AP_ARM_XEN_STARTING to CPUHP_AP_XEN_STARTING and use it for > x86, too. > > On the boot processor use the x86_init.irqs.intr_mode_init hook to > call xen_set_upcall_vector() only after the local APIC initialization. > As interrupts are on already at the time when the hook is being used, > modify xen_init_setup_upcall_vector() to disable interrupts. This is > needed as the xen_percpu_upcall flag is set only after the callback > has been registered, and the flag is needed for correctly acknowledging > an interrupt. > > Fixes: b1c3497e604d ("x86/xen: Add support for HVMOP_set_evtchn_upcall_vector") > Reported-by: Jan Beulich <jbeulich@suse.com> > Signed-off-by: Juergen Gross <jgross@suse.com>
Just to mention it here - as per [1] the issue may instead result from hypervisor misbehavior, so I guess we want to investigate that route first.
Jan
[1] https://lists.xen.org/archives/html/xen-devel/2022-11/msg00783.html
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