From: Andrew Cooper Date: Wed, 31 Aug 2011 14:19:24 +0000 (+0100) Subject: IRQ: manually EOI migrating line interrupts X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~9931 X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=12b6ea528fd6048bebcaee852d1b6be811907be3;p=xen.git IRQ: manually EOI migrating line interrupts When migrating IO-APIC line level interrupts between PCPUs, the migration code rewrites the IO-APIC entry to point to the new CPU/Vector before EOI'ing it. The EOI process says that EOI'ing the Local APIC will cause a broadcast with the vector number, which the IO-APIC must listen to to clear the IRR and Status bits. In the case of migrating, the IO-APIC has already been reprogrammed so the EOI broadcast with the old vector fails to match the new vector, leaving the IO-APIC with an outstanding vector, preventing any more use of that line interrupt. This causes a lockup especially when your root device is using PCI INTA (megaraid_sas driver *ehem*) However, the problem is mostly hidden because send_cleanup_vector() causes a cleanup of all moving vectors on the current PCPU in such a way which does not cause the problem, and if the problem has occured, the writes it makes to the IO-APIC clears the IRR and Status bits which unlocks the problem. This fix is distinctly a temporary hack, waiting on a cleanup of the irq code. It checks for the edge case where we have moved the irq, and manually EOI's the old vector with the IO-APIC which correctly clears the IRR and Status bits. Also, it protects the code which updates irq_cfg by disabling interrupts. Signed-off-by: Andrew Cooper --- diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c index dc92873311..a641856323 100644 --- a/xen/arch/x86/hpet.c +++ b/xen/arch/x86/hpet.c @@ -301,7 +301,7 @@ static void hpet_msi_ack(unsigned int irq) ack_APIC_irq(); } -static void hpet_msi_end(unsigned int irq) +static void hpet_msi_end(unsigned int irq, u8 vector) { } diff --git a/xen/arch/x86/i8259.c b/xen/arch/x86/i8259.c index 24f4f6d54c..55828ad633 100644 --- a/xen/arch/x86/i8259.c +++ b/xen/arch/x86/i8259.c @@ -93,7 +93,7 @@ static unsigned int startup_8259A_irq(unsigned int irq) return 0; /* never anything pending */ } -static void end_8259A_irq(unsigned int irq) +static void end_8259A_irq(unsigned int irq, u8 vector) { if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS))) enable_8259A_irq(irq); diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c index 471f7530e4..b333626791 100644 --- a/xen/arch/x86/io_apic.c +++ b/xen/arch/x86/io_apic.c @@ -1691,7 +1691,7 @@ static void mask_and_ack_level_ioapic_irq (unsigned int irq) } } -static void end_level_ioapic_irq (unsigned int irq) +static void end_level_ioapic_irq (unsigned int irq, u8 vector) { unsigned long v; int i; @@ -1740,6 +1740,14 @@ static void end_level_ioapic_irq (unsigned int irq) */ i = IO_APIC_VECTOR(irq); + /* Manually EOI the old vector if we are moving to the new */ + if ( vector && i != vector ) + { + int ioapic; + for (ioapic = 0; ioapic < nr_ioapics; ioapic++) + io_apic_eoi(ioapic, i); + } + v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1)); ack_APIC_irq(); @@ -1763,7 +1771,10 @@ static void disable_edge_ioapic_irq(unsigned int irq) { } -#define end_edge_ioapic_irq disable_edge_ioapic_irq +static void end_edge_ioapic_irq(unsigned int irq, u8 vector) +{ +} + /* * Level and edge triggered IO-APIC interrupts need different handling, @@ -1812,7 +1823,7 @@ static void ack_msi_irq(unsigned int irq) ack_APIC_irq(); /* ACKTYPE_NONE */ } -static void end_msi_irq(unsigned int irq) +static void end_msi_irq(unsigned int irq, u8 vector) { if ( !msi_maskable_irq(irq_desc[irq].msi_desc) ) ack_APIC_irq(); /* ACKTYPE_EOI */ diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c index f08137dd33..267b96faff 100644 --- a/xen/arch/x86/irq.c +++ b/xen/arch/x86/irq.c @@ -345,6 +345,7 @@ static void __do_IRQ_guest(int vector); void no_action(int cpl, void *dev_id, struct cpu_user_regs *regs) { } static void enable_none(unsigned int vector) { } +static void end_none(unsigned int irq, u8 vector) { } static unsigned int startup_none(unsigned int vector) { return 0; } static void disable_none(unsigned int vector) { } static void ack_none(unsigned int irq) @@ -353,7 +354,6 @@ static void ack_none(unsigned int irq) } #define shutdown_none disable_none -#define end_none enable_none hw_irq_controller no_irq_type = { "none", @@ -381,6 +381,7 @@ int __assign_irq_vector(int irq, struct irq_cfg *cfg, const cpumask_t *mask) static int current_vector = FIRST_DYNAMIC_VECTOR, current_offset = 0; unsigned int old_vector; int cpu, err; + unsigned long flags; cpumask_t tmp_mask; old_vector = irq_to_vector(irq); @@ -431,6 +432,7 @@ next: /* Found one! */ current_vector = vector; current_offset = offset; + local_irq_save(flags); if (old_vector) { cfg->move_in_progress = 1; cpus_copy(cfg->old_cpu_mask, cfg->cpu_mask); @@ -450,6 +452,7 @@ next: if (IO_APIC_IRQ(irq)) irq_vector[irq] = vector; err = 0; + local_irq_restore(flags); break; } return err; @@ -657,7 +660,7 @@ asmlinkage void do_IRQ(struct cpu_user_regs *regs) desc->status &= ~IRQ_INPROGRESS; out: - desc->handler->end(irq); + desc->handler->end(irq, regs->entry_vector); out_no_end: spin_unlock(&desc->lock); irq_exit(); @@ -857,7 +860,7 @@ static void irq_guest_eoi_timer_fn(void *data) switch ( action->ack_type ) { case ACKTYPE_UNMASK: - desc->handler->end(irq); + desc->handler->end(irq, 0); break; case ACKTYPE_EOI: cpu_eoi_map = action->cpu_eoi_map; @@ -885,7 +888,7 @@ static void __do_IRQ_guest(int irq) /* An interrupt may slip through while freeing an ACKTYPE_EOI irq. */ ASSERT(action->ack_type == ACKTYPE_EOI); ASSERT(desc->status & IRQ_DISABLED); - desc->handler->end(irq); + desc->handler->end(irq, vector); return; } @@ -1099,7 +1102,7 @@ static void flush_ready_eoi(void) ASSERT(irq > 0); desc = irq_to_desc(irq); spin_lock(&desc->lock); - desc->handler->end(irq); + desc->handler->end(irq, peoi[sp].vector); spin_unlock(&desc->lock); } @@ -1177,7 +1180,7 @@ void desc_guest_eoi(struct irq_desc *desc, struct pirq *pirq) if ( action->ack_type == ACKTYPE_UNMASK ) { ASSERT(cpus_empty(action->cpu_eoi_map)); - desc->handler->end(irq); + desc->handler->end(irq, 0); spin_unlock_irq(&desc->lock); return; } @@ -1431,7 +1434,7 @@ static irq_guest_action_t *__pirq_guest_unbind( case ACKTYPE_UNMASK: if ( test_and_clear_bool(pirq->masked) && (--action->in_flight == 0) ) - desc->handler->end(irq); + desc->handler->end(irq, 0); break; case ACKTYPE_EOI: /* NB. If #guests == 0 then we clear the eoi_map later on. */ diff --git a/xen/drivers/passthrough/amd/iommu_init.c b/xen/drivers/passthrough/amd/iommu_init.c index bfd60ada43..1a592329fa 100644 --- a/xen/drivers/passthrough/amd/iommu_init.c +++ b/xen/drivers/passthrough/amd/iommu_init.c @@ -441,7 +441,7 @@ static unsigned int iommu_msi_startup(unsigned int irq) return 0; } -static void iommu_msi_end(unsigned int irq) +static void iommu_msi_end(unsigned int irq, u8 vector) { iommu_msi_unmask(irq); ack_APIC_irq(); diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index c9557d12d5..44a5d317de 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -971,7 +971,7 @@ static unsigned int dma_msi_startup(unsigned int irq) return 0; } -static void dma_msi_end(unsigned int irq) +static void dma_msi_end(unsigned int irq, u8 vector) { dma_msi_unmask(irq); ack_APIC_irq(); diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h index 5aac1c94d0..647e2366b5 100644 --- a/xen/include/xen/irq.h +++ b/xen/include/xen/irq.h @@ -44,7 +44,7 @@ struct hw_interrupt_type { void (*enable)(unsigned int irq); void (*disable)(unsigned int irq); void (*ack)(unsigned int irq); - void (*end)(unsigned int irq); + void (*end)(unsigned int irq, u8 vector); void (*set_affinity)(unsigned int irq, cpumask_t mask); };