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authorVitaly Kuznetsov <vkuznets@redhat.com>2015-10-15 19:42:23 +0200
committerThomas Gleixner <tglx@linutronix.de>2015-10-16 16:31:24 +0200
commitc0ff971ef9acacd4d2caa508e444edad958dead9 (patch)
tree9b9a890cfaf1c095149bdd49b50edfffeb5c8f06 /arch
parent1a800589052f03ce09008f82ad2c69f0af5d315a (diff)
x86/ioapic: Disable interrupts when re-routing legacy IRQs
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. Protect the setup sequence against concurrent interrupts. [ tglx: Make the protection unconditional and not only for legacy interrupts ] Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: K. Y. Srinivasan <kys@microsoft.com> Link: http://lkml.kernel.org/r/1444930943-19336-1-git-send-email-vkuznets@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/apic/io_apic.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 5c60bb162622..bb6bfc01cb82 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;
if (!info || nr_irqs > 1)
return -EINVAL;
@@ -2939,11 +2940,14 @@ 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);
+
+ 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())
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",