On 28/09/2022 09:58, Janusz Krzysztofik wrote:
Manual revert of commit f598a497bc7d ("iova: Add CPU hotplug handler to
flush rcaches"). It is trying to instantiate a cpuhp notifier from inside
a cpuhp callback. That code replaced intel_iommu implementation of
flushing per-IOVA domain CPU rcaches which used a single instance of cpuhp
held for the module lifetime.
v2: Restore formerly reverted commit ac9a5d522bb8 "iommu/dma: Fix race
condition during iova_domain initialization" after we have this more
effective fix applied. The former occurred not sufficient and is no
longer needed once we have the latter in place.
Note: I'm no longer CCing IOMMU nor mainstream, they have been already
warned.
Will that also fix the one below?
<4> [18.297089] ================================
<4> [18.297090] WARNING: inconsistent lock state
<4> [18.297092] 6.0.0-rc2-CI_DINF_262-g320305923c88+ #1 Not tainted
<4> [18.297095] --------------------------------
<4> [18.297096] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
<4> [18.297098] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
<4> [18.297101] ffff8881030ed678 (&domain->lock){+.?.}-{2:2}, at: iommu_flush_dev_iotlb.part.61+0x23/0x80
<4> [18.297108] {SOFTIRQ-ON-W} state was registered at:
<4> [18.297110] lock_acquire+0xd3/0x310
<4> [18.297113] _raw_spin_lock+0x2a/0x40
<4> [18.297116] domain_update_iommu_cap+0x20b/0x2c0
<4> [18.297118] intel_iommu_attach_device+0x5bd/0x860
<4> [18.297121] __iommu_attach_device+0x18/0xe0
<4> [18.297124] bus_iommu_probe+0x1f3/0x2d0
<4> [18.297126] bus_set_iommu+0x82/0xd0
<4> [18.297129] intel_iommu_init+0xe45/0x102a
<4> [18.297132] pci_iommu_init+0x9/0x31
<4> [18.297135] do_one_initcall+0x53/0x2f0
<4> [18.297138] kernel_init_freeable+0x18f/0x1e1
<4> [18.297140] kernel_init+0x11/0x120
<4> [18.297143] ret_from_fork+0x1f/0x30
<4> [18.297145] irq event stamp: 512712
<4> [18.297147] hardirqs last enabled at (512712): [<ffffffff81b59254>] _raw_spin_unlock_irqrestore+0x54/0x70
<4> [18.297151] hardirqs last disabled at (512711): [<ffffffff81b58ffb>] _raw_spin_lock_irqsave+0x4b/0x50
<4> [18.297155] softirqs last enabled at (512700): [<ffffffff81e00323>] __do_softirq+0x323/0x48e
<4> [18.297158] softirqs last disabled at (512705): [<ffffffff810c16a8>] irq_exit_rcu+0xb8/0xe0
<4> [18.297162]
other info that might help us debug this:
<4> [18.297164] Possible unsafe locking scenario:
<4> [18.297166] CPU0
<4> [18.297168] ----
<4> [18.297169] lock(&domain->lock);
<4> [18.297171] <Interrupt>
<4> [18.297172] lock(&domain->lock);
<4> [18.297174]
*** DEADLOCK ***
<4> [18.297176] 1 lock held by swapper/0/0:
<4> [18.297177] #0: ffffc90000003ea8 ((&cookie->fq_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x2c0
<4> [18.297183]
stack backtrace:
<4> [18.297185] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.0.0-rc2-CI_DINF_262-g320305923c88+ #1
<4> [18.297189] Hardware name: ASUS System Product Name/ROG STRIX B660-I GAMING WIFI, BIOS 0415 09/29/2021
<4> [18.297192] Call Trace:
<4> [18.297193] <IRQ>
<4> [18.297195] dump_stack_lvl+0x56/0x7f
<4> [18.297198] mark_lock.part.47+0x8d1/0xdb0
<4> [18.297200] ? qi_submit_sync+0x3c8/0x650
<4> [18.297203] __lock_acquire+0x861/0xb90
<4> [18.297205] lock_acquire+0xd3/0x310
<4> [18.297207] ? iommu_flush_dev_iotlb.part.61+0x23/0x80
<4> [18.297211] ? iommu_dma_map_sg+0x400/0x400
<4> [18.297213] _raw_spin_lock+0x2a/0x40
<4> [18.297215] ? iommu_flush_dev_iotlb.part.61+0x23/0x80
<4> [18.297218] iommu_flush_dev_iotlb.part.61+0x23/0x80
<4> [18.297220] intel_flush_iotlb_all+0x95/0x110
<4> [18.297223] fq_flush_iotlb+0x1d/0x30
<4> [18.297225] fq_flush_timeout+0x28/0xc0
<4> [18.297227] ? iommu_dma_map_sg+0x400/0x400
<4> [18.297229] ? iommu_dma_map_sg+0x400/0x400
<4> [18.297231] call_timer_fn+0x9c/0x2c0
<4> [18.297234] run_timer_softirq+0x548/0x570
<4> [18.297237] __do_softirq+0xda/0x48e
<4> [18.297240] irq_exit_rcu+0xb8/0xe0
<4> [18.297242] sysvec_apic_timer_interrupt+0x9e/0xc0
<4> [18.297245] </IRQ>
Regards,
Tvrtko
Chris Wilson (1):
iommu: Remove iova cpu hotplugging flushing
Janusz Krzysztofik (1):
Restore "iommu/dma: Fix race condition during iova_domain
initialization"
drivers/iommu/dma-iommu.c | 17 +++++++++++++----
drivers/iommu/iova.c | 28 ----------------------------
include/linux/cpuhotplug.h | 1 -
include/linux/iova.h | 1 -
4 files changed, 13 insertions(+), 34 deletions(-)
