From 9facd54a45725f6d5c21c0e531b9a0f5e76ebaef Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 17 Apr 2012 15:35:39 +0200 Subject: [PATCH] x86/ioapic: Add register level checks to detect bogus io-apic entries With the recent changes to clear_IO_APIC_pin() which tries to clear remoteIRR bit explicitly, some of the users started to see "Unable to reset IRR for apic .." messages. Close look shows that these are related to bogus IO-APIC entries which returns all 1s for their io-apic registers. And the above mentioned error messages are benign. But kernel should have ignored such io-apic's in the first place. Check if register 0, 1, 2 of the listed io-apic are all 1s and ignore such io-apic. [original Linux patch:] Signed-off-by: Suresh Siddha Signed-off-by: Jan Beulich Acked-by: Keir Fraser Committed-by: Jan Beulich --- xen/arch/x86/io_apic.c | 47 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c index 72b32ce46b..32420d8ce9 100644 --- a/xen/arch/x86/io_apic.c +++ b/xen/arch/x86/io_apic.c @@ -185,7 +185,7 @@ struct IO_APIC_route_entry **alloc_ioapic_entries(void) ioapic_entries[apic] = xmalloc_array(struct IO_APIC_route_entry, nr_ioapic_entries[apic]); - if (!ioapic_entries[apic]) + if (!ioapic_entries[apic] && nr_ioapic_entries[apic]) goto nomem; } @@ -310,6 +310,9 @@ int save_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries) return -ENOMEM; for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; + if (!ioapic_entries[apic]) return -ENOMEM; @@ -331,6 +334,9 @@ void mask_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries) return; for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; + if (!ioapic_entries[apic]) break; @@ -358,6 +364,9 @@ int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries) return -ENOMEM; for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; + if (!ioapic_entries[apic]) return -ENOMEM; @@ -610,6 +619,8 @@ static int __init find_isa_irq_apic(int irq, int type) if (i < mp_irq_entries) { int apic; for(apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; if (mp_ioapics[apic].mpc_apicid == mp_irqs[i].mpc_dstapic) return apic; } @@ -1080,6 +1091,8 @@ static void /*__init*/ __print_IO_APIC(void) printk(KERN_INFO "testing the IO APIC.......................\n"); for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; spin_lock_irqsave(&ioapic_lock, flags); reg_00.raw = io_apic_read(apic, 0); @@ -1229,6 +1242,8 @@ static void __init enable_IO_APIC(void) if (directed_eoi_enabled) { for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; vector_map[apic] = xzalloc(vmask_t); BUG_ON(!vector_map[apic]); } @@ -1354,6 +1369,8 @@ static void __init setup_ioapic_ids_from_mpc(void) * Set the IOAPIC ID to the value stored in the MPC table. */ for (apic = 0; apic < nr_ioapics; apic++) { + if (!nr_ioapic_entries[apic]) + continue; /* Read the register 0 value */ spin_lock_irqsave(&ioapic_lock, flags); @@ -2038,6 +2055,8 @@ void ioapic_resume(void) spin_lock_irqsave(&ioapic_lock, flags); for (apic = 0; apic < nr_ioapics; apic++){ + if (!nr_ioapic_entries[apic]) + continue; reg_00.raw = __io_apic_read(apic, 0); if (reg_00.bits.ID != mp_ioapics[apic].mpc_apicid) { reg_00.bits.ID = mp_ioapics[apic].mpc_apicid; @@ -2225,8 +2244,12 @@ static int ioapic_physbase_to_id(unsigned long physbase) { int apic; for ( apic = 0; apic < nr_ioapics; apic++ ) + { + if ( !nr_ioapic_entries[apic] ) + continue; if ( mp_ioapics[apic].mpc_apicaddr == physbase ) return apic; + } return -EINVAL; } @@ -2444,6 +2467,22 @@ void dump_ioapic_irq_info(void) static unsigned int __initdata max_gsi_irqs; integer_param("max_gsi_irqs", max_gsi_irqs); +static __init bool_t bad_ioapic_register(unsigned int idx) +{ + union IO_APIC_reg_00 reg_00 = { .raw = io_apic_read(idx, 0) }; + union IO_APIC_reg_01 reg_01 = { .raw = io_apic_read(idx, 1) }; + union IO_APIC_reg_02 reg_02 = { .raw = io_apic_read(idx, 2) }; + + if ( reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1 ) + { + printk(KERN_WARNING "I/O APIC %#x registers return all ones, skipping!\n", + mp_ioapics[idx].mpc_apicaddr); + return 1; + } + + return 0; +} + void __init init_ioapic_mappings(void) { unsigned long ioapic_phys; @@ -2477,6 +2516,12 @@ void __init init_ioapic_mappings(void) __fix_to_virt(idx), ioapic_phys); idx++; + if ( bad_ioapic_register(i) ) + { + __set_fixmap(idx, 0, 0); + continue; + } + if ( smp_found_config ) { /* The number of IO-APIC IRQ registers (== #pins): */ -- 2.30.2