I tested kernel #2 on Wily. I attached 3 legacy network adapters and all of them got IP addresses, so the changes are ok.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1508593 Title: [Hyper-V] x86/ioapic: Disable interrupts when re-routing legacy IRQs Status in linux package in Ubuntu: Triaged Status in linux source package in Trusty: In Progress Status in linux source package in Vivid: In Progress Status in linux source package in Wily: In Progress Bug description: A sporadic hang with consequent crash is observed when booting Hyper-V Gen1 guests... Sauce request for upstream submission: https://lkml.org/lkml/2015/10/15/673 From Vitaly Kuznetsov <> Subject [PATCH] x86/ioapic: Disable interrupts when re-routing legacy IRQs Date Thu, 15 Oct 2015 19:42:23 +0200 A sporadic hang with consequent crash is observed when booting Hyper-V Gen1 guests: Call Trace: <IRQ> [<ffffffff810ab68d>] ? trace_hardirqs_off+0xd/0x10 [<ffffffff8107b616>] queue_work_on+0x46/0x90 [<ffffffff81365696>] ? add_interrupt_randomness+0x176/0x1d0 ... <EOI> [<ffffffff81471ddb>] ? _raw_spin_unlock_irqrestore+0x3b/0x60 [<ffffffff810c295e>] __irq_put_desc_unlock+0x1e/0x40 [<ffffffff810c5c35>] irq_modify_status+0xb5/0xd0 [<ffffffff8104adbb>] mp_register_handler+0x4b/0x70 [<ffffffff8104c55a>] mp_irqdomain_alloc+0x1ea/0x2a0 [<ffffffff810c7f10>] irq_domain_alloc_irqs_recursive+0x40/0xa0 [<ffffffff810c860c>] __irq_domain_alloc_irqs+0x13c/0x2b0 [<ffffffff8104b070>] alloc_isa_irq_from_domain.isra.1+0xc0/0xe0 [<ffffffff8104bfa5>] mp_map_pin_to_irq+0x165/0x2d0 [<ffffffff8104c157>] pin_2_irq+0x47/0x80 [<ffffffff81744253>] setup_IO_APIC+0xfe/0x802 ... [<ffffffff814631c0>] ? rest_init+0x140/0x140 The issue is easily reproducible with a simple instrumentation: if mdelay(10) is put between mp_setup_entry() and mp_register_handler() calls in mp_irqdomain_alloc() Hyper-V guest always fails to boot when re-routing IRQ0. The issue seems to be caused by the fact that we don't disable interrupts while doing IOPIC programming for legacy IRQs and IRQ0 actually happens. Decorate manipulations with legacy IRQs with local_irq_save()/ local_irq_restore(). Cc: Thomas Gleixner <t...@linutronix.de> Cc: Ingo Molnar <mi...@redhat.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Jiang Liu <jiang....@linux.intel.com> Cc: Yinghai Lu <ying...@kernel.org> Cc: K. Y. Srinivasan <k...@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> --- It may make sense to have interrupts disabled for non-legacy IRQs as well but I'm unaware of any bugs with them at this moment. --- arch/x86/kernel/apic/io_apic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 5c60bb1..9aac777 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2907,6 +2907,7 @@ int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq, struct irq_data *irq_data; struct mp_chip_data *data; struct irq_alloc_info *info = arg; + unsigned long flags = 0; if (!info || nr_irqs > 1) return -EINVAL; @@ -2939,11 +2940,16 @@ int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq, cfg = irqd_cfg(irq_data); add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin); + + if (virq < nr_legacy_irqs()) + local_irq_save(flags); if (info->ioapic_entry) mp_setup_entry(cfg, data, info->ioapic_entry); mp_register_handler(virq, data->trigger); - if (virq < nr_legacy_irqs()) + if (virq < nr_legacy_irqs()) { legacy_pic->mask(virq); + local_irq_restore(flags); + } apic_printk(APIC_VERBOSE, KERN_DEBUG "IOAPIC[%d]: Set routing entry (%d-%d -> 0x%x -> IRQ %d Mode:%i Active:%i Dest:%d)\n", -- 2.4.3 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1508593/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
