Intel VT-d driver was reworked to use common deferred flushing implementation. Previously there was one global per-cpu flush queue, afterwards - one per domain. Before deferring a flush, the queue should be allocated and initialized. Currently only domains with IOMMU_DOMAIN_DMA type initialize their flush queue. It's probably worth to init it for static or unmanaged domains too, but it may be arguable - I'm leaving it to iommu folks. Prevent queuing an iova flush if the domain doesn't have a queue. The defensive check seems to be worth to keep even if queue would be initialized for all kinds of domains. And is easy backportable. On 4.19.43 stable kernel it has a user-visible effect: previously for devices in si domain there were crashes, on sata devices: BUG: spinlock bad magic on CPU#6, swapper/0/1 lock: 0xffff88844f582008, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #1 Call Trace: <IRQ> dump_stack+0x61/0x7e spin_bug+0x9d/0xa3 do_raw_spin_lock+0x22/0x8e _raw_spin_lock_irqsave+0x32/0x3a queue_iova+0x45/0x115 intel_unmap+0x107/0x113 intel_unmap_sg+0x6b/0x76 __ata_qc_complete+0x7f/0x103 ata_qc_complete+0x9b/0x26a ata_qc_complete_multiple+0xd0/0xe3 ahci_handle_port_interrupt+0x3ee/0x48a ahci_handle_port_intr+0x73/0xa9 ahci_single_level_irq_intr+0x40/0x60 __handle_irq_event_percpu+0x7f/0x19a handle_irq_event_percpu+0x32/0x72 handle_irq_event+0x38/0x56 handle_edge_irq+0x102/0x121 handle_irq+0x147/0x15c do_IRQ+0x66/0xf2 common_interrupt+0xf/0xf RIP: 0010:__do_softirq+0x8c/0x2df The same for usb devices that use ehci-pci: BUG: spinlock bad magic on CPU#0, swapper/0/1 lock: 0xffff88844f402008, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #4 Call Trace: <IRQ> dump_stack+0x61/0x7e spin_bug+0x9d/0xa3 do_raw_spin_lock+0x22/0x8e _raw_spin_lock_irqsave+0x32/0x3a queue_iova+0x77/0x145 intel_unmap+0x107/0x113 intel_unmap_page+0xe/0x10 usb_hcd_unmap_urb_setup_for_dma+0x53/0x9d usb_hcd_unmap_urb_for_dma+0x17/0x100 unmap_urb_for_dma+0x22/0x24 __usb_hcd_giveback_urb+0x51/0xc3 usb_giveback_urb_bh+0x97/0xde tasklet_action_common.isra.4+0x5f/0xa1 tasklet_action+0x2d/0x30 __do_softirq+0x138/0x2df irq_exit+0x7d/0x8b smp_apic_timer_interrupt+0x10f/0x151 apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0010:_raw_spin_unlock_irqrestore+0x17/0x39
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| @@ -155,6 +155,7 @@ struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo, · 154 unmodified lines | |||
| 155 | void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to); | 155 | void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to); |
| 156 | void init_iova_domain(struct iova_domain *iovad, unsigned long granule, | 156 | void init_iova_domain(struct iova_domain *iovad, unsigned long granule, |
| 157 | unsigned long start_pfn); | 157 | unsigned long start_pfn); |
| 158 | bool has_iova_flush_queue(struct iova_domain *iovad); | ||
| 158 | int init_iova_flush_queue(struct iova_domain *iovad, | 159 | int init_iova_flush_queue(struct iova_domain *iovad, |
| 159 | iova_flush_cb flush_cb, iova_entry_dtor entry_dtor); | 160 | iova_flush_cb flush_cb, iova_entry_dtor entry_dtor); |
| 160 | struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn); | 161 | struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn); |
| @@ -235,6 +236,11 @@ static inline void init_iova_domain(struct iova_domain *iovad, · 74 unmodified lines | |||
| 235 | { | 236 | { |
| 236 | } | 237 | } |
| 237 | 238 | ||
| 239 | bool has_iova_flush_queue(struct iova_domain *iovad) | ||
| 240 | { | ||
| 241 | return false; | ||
| 242 | } | ||
| 243 | |||
| 238 | static inline int init_iova_flush_queue(struct iova_domain *iovad, | 244 | static inline int init_iova_flush_queue(struct iova_domain *iovad, |
| 239 | iova_flush_cb flush_cb, | 245 | iova_flush_cb flush_cb, |
| 240 | iova_entry_dtor entry_dtor) | 246 | iova_entry_dtor entry_dtor) |