This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- wily' to 'verification-done-wily'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-wily -- 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: Fix Committed 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 <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Jiang Liu <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: K. Y. Srinivasan <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> --- 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 : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
