From: Jason Andryuk Date: Fri, 17 Oct 2025 13:41:17 +0000 (-0400) Subject: xen/events: Update virq_to_irq on migration X-Git-Tag: v6.1.157~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b8291d6d98545d954f3d7fa46f5655e2b8a23973;p=thirdparty%2Fkernel%2Fstable.git xen/events: Update virq_to_irq on migration [ Upstream commit 3fcc8e146935415d69ffabb5df40ecf50e106131 ] VIRQs come in 3 flavors, per-VPU, per-domain, and global, and the VIRQs are tracked in per-cpu virq_to_irq arrays. Per-domain and global VIRQs must be bound on CPU 0, and bind_virq_to_irq() sets the per_cpu virq_to_irq at registration time Later, the interrupt can migrate, and info->cpu is updated. When calling __unbind_from_irq(), the per-cpu virq_to_irq is cleared for a different cpu. If bind_virq_to_irq() is called again with CPU 0, the stale irq is returned. There won't be any irq_info for the irq, so things break. Make xen_rebind_evtchn_to_cpu() update the per_cpu virq_to_irq mappings to keep them update to date with the current cpu. This ensures the correct virq_to_irq is cleared in __unbind_from_irq(). Fixes: e46cdb66c8fc ("xen: event channels") Cc: stable@vger.kernel.org Signed-off-by: Jason Andryuk Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20250828003604.8949-4-jason.andryuk@amd.com> [ Adjust context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index c2e41d6cab9ed..9052a4873bca8 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1807,9 +1807,20 @@ static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu) * virq or IPI channel, which don't actually need to be rebound. Ignore * it, but don't do the xenlinux-level rebind in that case. */ - if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0) + if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0) { + int old_cpu = info->cpu; + bind_evtchn_to_cpu(evtchn, tcpu, false); + if (info->type == IRQT_VIRQ) { + int virq = info->u.virq; + int irq = per_cpu(virq_to_irq, old_cpu)[virq]; + + per_cpu(virq_to_irq, old_cpu)[virq] = -1; + per_cpu(virq_to_irq, tcpu)[virq] = irq; + } + } + do_unmask(info, EVT_MASK_REASON_TEMPORARY); return 0;